Mk4 Mondeo 2.0 TDCI Limp Mode

[Tdci-Peter]

9 hours ago, Dee_82 said:

Google suggests that it might be that Engine speed data doesn't match what the ABS sensors are telling it.

Sounds a bit improbable to me. Engine speed (RPM) is linked to the wheels & ABS sensors via the gearbox, and on most manual Fords, there is no sensor saying what gear it is in. On an auto there may slip as well as gear ratios, so it could be even harder to correlate the two.

But those EML ON notes do shift attention to the ABS. It seems to be reporting two comms errors, to the SASM and to the PCM. Invalid data is more likely to mean the data packets could not be read at all, or the numbers are out of allowed range altogether (junk).

The ABS does traction control, and I would guess the algorithm to do that is in the ABS. So it will request RPM and maybe accelerator position from the PCM, and presumably effectively over-ride the accelerator when it detects wheel spin. So the problem could well be when the ABS reads RPM from the PCM, but I don't see it just being a numeric mismatch.

Faults in the wheel speed sensors usually put the ABS light on and raise suitable DTCs, so they seem to be ok. Maybe the fault is in the ABS electronic module, or in the wiring or connector.

However the PCM and/or IC are reading data from the ABS ok to get vehicle speed. So the CAN bus connections seem to be ok. Bit of a mystery why the ABS is reporting difficulty in communicating!

On the APP, do you have to move the accelerator during the BCM test? The spike in sensor E is interesting, but it is hard to link it up with the ABS comms faults that are putting the EML on.

[Dee_82]

It's all very curious isn't it

Yesterday, I did a long drive whilst recording all the ABS PIDs, the very second I engaged CC, forscan lost Comms with OBD. Reinitialised it and it worked for a short while but eventually bombed out again 5 Min later. No DTCs at all, all ABS sensors reported correct speed (within 1mph). Switched back to recording PCM and no trouble. 

Now I was using my BT adapter at the time so I'll try reproducing with my good USB elm device just incase it's BT related.

The BCM test doesn't require any input from the driver

I measured resistance to ground on the two ground pins, the power ground  was nominal, the data "ground" was 20ohms (to another ground point) since it's going through the BCM I'm not surprised its got some resistance but I'll need to find the connector and measure it end to end to be sure.

That leaves data and voltage pins, 

12.5, 11.1, GND, GND, 0.14, 5.1

I asked a mate to record his and he got similar numbers except on pin 5

12.2, 10.9, GND, GND, 0.05, 5

Its almost as if their is some noise on the CAN, which is throwing things out. Do you know of a way to mirror raw data from the CAN. 

[Tdci-Peter]

2 hours ago, Dee_82 said:

I did a long drive whilst recording all the ABS PIDs, the very second I engaged CC, forscan lost Comms with OBD. Reinitialised it and it worked for a short while but eventually bombed out again 5 Min later. No DTCs at all, all ABS sensors reported correct speed (within 1mph). Switched back to recording PCM and no trouble. 

I have been using digital bus systems since the 1970s, from 8 bit parallel to USB. But I have never had the time or opportunity to look at the CAN protocols in any detail. I have only looked at the driver specs of CAN, to see what the physical interface is like.

But HS-CAN is not really very fast at all, 1MBPS I think, compared to old USB1 which is 12MBPS. So time constraints on a heavily used bus will be significant. CC will increase the bus loading, the PCM normally has little interest in vehicle speed. If the CC algorithm is in the PCM, then it will need frequent updates of speed, if it is in the ABS, then the power (accelerator over-ride) needs frequent updates. It looks like your ABS is either a bit slow, and the ELM is timing out when requesting data from the ABS when heavily in use, or the ABS is sensitive to the extra loading of reading PIDs while doing CC, and is ignoring, corrupting or delaying the PID data requests.

Whether these problems reflect a fault in your ABS, or are just normal for the car, I can not say. A test with a USB ELM is a good idea, BT is a very poor match to CAN as BT is optimised for larger blocks of data, with very significant protocol delays between blocks, as it fights to get bandwidth on a noisy little bit of RF spectrum. WiFi is probably even worse in this respect.

I can think of some faults in an ABS that will cause errors on heavy bus loading: Open circuit de-coupling capacitors, component value changes, pin leakage current in ICs, conduction (eg contamination) between pcb traces  these could all result in CAN comms being below par, with frequent error detection & re-try. With light bus loading, all may look ok, but it will slow down to the point of not operating under heavy load.

But that is not a diagnosis, just a suggestion! There are too many other suspects in the frame at the moment, from SASM to BCM. I have vaguely heard of tools that can monitor CAN traffic, but have no experience or detailed knowledge of them.

Is there a PID that directly monitors the SASM? I think SASM is on the HS-CAN bus in the mondy, Heavily loading requests to the SASM would help push that one out of the frame.

 

 

[Dee_82]

Thanks Peter, 

The USB interface didn't produce the same lost comms as the BT one did when monitoring ABS so I think your correct with that part, it does have exactly the same errors with regards to forscan tests on ABS / BCM. 

there are a bunch of SASM PIDs I can monitor, I could request the lot with the USB interface then try messing around with CC. 

From my limited understanding of the way in which CAN works, each sensor relays information to its respected control module(Node), that node doesn't automatically spam out that information on to the CAN unless something requests it in which case its packaged up and relayed over CAN with an ID, everything on the network gets the packet but only the node it was intended for should acknowledge it, it can easily be overloaded, so if I gather as many PIDs as possible we could cause Some problems and on occasion I think I have seen this happen in real time, the polling of the PIDs appears to be reduced and becomes visibly slower at updating, which I think makes sense as when we get overloading there should be Error frames passed along the network to try any sort itself out (excuse the layman terms!)

But I know for a fact that the CAN BUS can cope with more than im trying to collect through it so if I can find a way to log all the frames with like Wireshark can over the TCP IP Stack, maybe I can identify whats going on...… Im pretty sure it uses simple AT commands so as long as its not encrypted it should be all there to see with the USB interface and console...

I briefly looked at the hassle of replacing the ABS and low behold, its a big job, never mind the physical side, apparently the Mondeo Mk4 uses ABS as part of the PATS system in the same way the mk 2 focus uses the IC and BCM. So changing it would require a reprograming job

[Tdci-Peter]

On 10/22/2018 at 6:55 PM, Dee_82 said:

there are a bunch of SASM PIDs I can monitor,

My thinking with the SASM is that there are reported comms errors between ABS and SASM already. There is likely to be quite a lot of traffic between these two, as the over/under steer conditions that ESP is intended to reduce are likely to be caused by rapid steering movement, and the ABS would have to react quickly to this. So it may be polling the SASM at quite a high rate. Add the demands of CC, and if either SASM or ABS CAN bus circuits are below par, there will be a lot of errors and mashed data.

If there is a possible problem with the SASM, this might be a lot easier to swap than the ABS. I don't suppose you can disable ESP on your car like I can on mine. The Mk2 Focus has an off button. It has enabled me to identify a slightly annoying hissy noise I get on bumpy bends as an over-active ESP.

I just read up a little on CAN, it uses collision detection, where multiple modules can start transmitting together. They must listen to the bus while transmitting, one bit state over-rides the other, and any module that detects its bit has been over-ridden must instantly shut up and wait, while the winner has its say. This relies on accurate bit rate synchronisation between all modules to work. Small faults in this can lead to chaos on the bus.

I don't much like CAN, compared to USB it seems slow and unreliable. The only upside is that the hardware spec for the drivers is very tough, they are intended to withstand voltages way above normal.

This is a tough nut to crack, the Turbo actuator started as main suspect, we are now relying on both Forscan and the software in the car being correct in saying the EML is on for the ABS related errors. I guess you will have to keep trying things until either you are fed up with the car, or something happens to identify the problem. I think a Ford dealer would just change expensive parts at your cost until maybe it got fixed!

 

[Dee_82]

Yeah, the SASM can easily be replaced, I took a look at it yesterday and it looks straight forward enough. The Mondeo has a notoriously shoddy SASM but it usually manifests in CC not working at all.

I have been able to interface with the CAN and have been able to read traffic

> 7E7 03 41 05 33 AA AA AA AA 
< 7DF 02 01 0B 00 00 00 00 00 
> 7E7 03 41 0B 63 AA AA AA AA 
< 7DF 02 01 0C 00 00 00 00 00 
> 7E7 04 41 0C 0C 98 AA AA AA 
< 7DF 02 01 0D 00 00 00 00 00 
> 7E7 03 41 0D 00 AA AA AA AA 
< 7DF 02 01 0E 00 00 00 00 00 
> NO DATA
< 7DF 02 01 0F 00 00 00 00 00 
> 7E7 03 41 0F 35 AA AA AA AA 
< 7DF 02 01 11 00 00 00 00 00 

7DF is the OBD Header

7E7 is a node or a control module header (I think!), which one I haven't scoobie.  In just a few seconds of collecting data I gathered over 4000 communications.  

I think the next bit is the target or destination

No Data is a response when a question was not answered within an acceptable time frame.

To tell you the truth its beyond me, I hadn't realised there would be as much flying around as this and this is before the car is even turned on!

I might just change the SASM since its relatively simple and being in front of the driver its not unrealistic to think of there being some contamination on the PCB.

The SASM and ABS are at opposite ends of the network with the SASM and  CJB at one end and the ABS and PCM at the other. its not going to be a termination problem since everything else is ok so if it is a CAN problem I think we can rule out the CJB and PCM but that also means anything along the path could be causing it.

I did replace the headunit with my old headunit from my Mk2 Focus and I swapped out the IC for a different one as well but both the IC and the Headunit are on a separate network to the SASM.

However, after just checking the wiring diagrams whilst the CAN is separate the SASM physically pass through the IC as does the head unit so whilst not linked directly via CAN they are connected directly via the IC which bridges the MM-CAN and the two MS/HS-CAN along side some direct connections to the IC, audio and SASM...

----------------------------------------------------------------------------------------------------------------------------

But now Ive said that, that has got me thinking....

Below is the initial list of DTCs in the car, before this point there was no limp mode that we know of, DTCs hadn't been cleared for about 20k miles, there was hesitation but I suspect that was the EGR which has been fixed. the Fan DTC has been taken care off and the CC DTCs have now gone since I cleaned it out. 

The IC and headunit both work absolutely fine, I did swap out the IC to see if it make a difference and it didn't but I hadn't pulled the head unit though which connects to the IC and SASM, I wonder if that assumption might play in to this sorry mess albeit ive never heard of a headunit causing so much fuss..

 

 

===PCM DTC P0691:00-6C===
Code: P0691 - Fan 1 Control Circuit Low

Status: 
 - DTC Maturing - Intermittent at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC
 - Test not complete

Module: Powertrain Control Module

===END PCM DTC P0691:00-6C===

===PCM DTC U0405:00-6C===
Code: U0405 - Invalid Data Received from Cruise Control Module

Status: 
 - DTC Maturing - Intermittent at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC
 - Test not complete

Module: Powertrain Control Module

===END PCM DTC U0405:00-6C===

===PCM DTC P003A:16-28===
Code: P003A - Turbocharger/Supercharger Boost Control A Position Exceeded Learning Limit

Additional Fault Symptom:
 - Circuit Voltage Below Threshold

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Powertrain Control Module

===END PCM DTC P003A:16-28===

===OBDII DTC None===
Successful DTC reading, no error codes found

Module: On Board Diagnostic II

===END OBDII DTC None===

===SASM DTC None===
Successful DTC reading, no error codes found

Module: Steering Angle Sensor Module

===END SASM DTC None===

===ABS DTC B1B69:16-08===
Code: B1B69 - 12 Volt Supply Circuit

Additional Fault Symptom:
 - Circuit Voltage Below Threshold

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Antilock braking system

Diagnostic Trouble Code details

There could be a low supply voltage and it is below the threshold level for the system to operate.

There could be a high supply voltage and it is above the threshold level for the system to operate.

There will be other DTCs set in the ABS module.

There are DTCs for other modules.

Note: This DTC may set after a 24 volt jump start.

Discharged or faulty battery.

The generator is undercharging

DO NOT replace  the ABS module based on this DTC alone.

Perform these checks

Check Supply Voltage

Check the battery charging system.

Check the condition of the battery.

Check for non-standard accessories and vehicle modifications

Check the wiring and the appropriate fuse.

Check the terminals are secure and not corroded.

High resistance in wiring

Fully charge the battery then carry out the Battery Capacity Test.

Check the power and ground circuit.

Check the connector for damage or contamination.

Check for an open circuit in the wiring harness.

Check for a short circuit to the ground or battery.

Check the condition of all cables and connectors for broken cables, damaged insulation, contamination, water ingress and loose connections.

Check the condition of all cables and connectors for broken cables, damaged insulation, contamination and loose connections.  Make sure there is no continuity to ground or supply.

Check the ABS module connections for damage, water ingress or corrosion . If any contamination is found, clean the connector and ABS module terminals.

Check the ABS module fuse.

Check All Other Modules On The Data Bus For Function And DTCs

There will be no CAN communication.

If the DTC is CMDTCs and historically this may be an intermittent fault, the cause of which cannot be identified at this time. The customer should return the car should the fault reoccur noting the conditions at the time of the failure like the speed and application of the brakes.

Additional Information

The ABS lamp is illuminated.

The ESP lamp is illuminated.

There will be an ESP malfunction warning displayed on the driver information text panel.

The EBD Warning Lamp is illuminated.

===END ABS DTC B1B69:16-08===

===ABS DTC U3001:00-08===
Code: U3001 - Control Module Improper Shutdown

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Antilock braking system

===END ABS DTC U3001:00-08===

===BCMii DTC B10AC:95-2F===
Code: B10AC - Cruise Control Switch

Additional Fault Symptom:
 - Incorrect Assembly

Status: 
 - DTC Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Body Control Module

 Freeze Frame :
-GLOBTIM: 276073945 sec - Global real time
-TOTDIST: 162762.0 km - Total Distance
-MAINECUV: 14.50 Volt - Main ECU voltage supply
-ESTSERUN: Yes  - Engine status - engine running
-ESTSECRK: No  - Engine status - engine in crank
-INCARTMP: 25 °C - In car temperature
===END BCMii DTC B10AC:95-2F===

===BCMii DTC B1108:77-68===
Code: B1108 - Driver door central locking motor

Additional Fault Symptom:
 - Commanded Position Not Reachable

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC
 - Test not complete

Module: Body Control Module

 Freeze Frame :
-GLOBTIM: 273449051 sec - Global real time
-TOTDIST: 160883.0 km - Total Distance
-MAINECUV: 12.00 Volt - Main ECU voltage supply
-ESTSERUN: No  - Engine status - engine running
-ESTSECRK: No  - Engine status - engine in crank
===END BCMii DTC B1108:77-68===

===PDM DTC None===
Successful DTC reading, no error codes found

Module: Passengers Door Control Unit

===END PDM DTC None===

===DDM DTC None===
Successful DTC reading, no error codes found

Module: Drivers Door Module

===END DDM DTC None===

===RCM DTC None===
Successful DTC reading, no error codes found

Module: Restraint Control Module

===END RCM DTC None===

===HVAC DTC None===
Successful DTC reading, no error codes found

Module: Heating Ventilation Air Conditioning

===END HVAC DTC None===

===ACM DTC None===
Successful DTC reading, no error codes found

Module: Audio Control Module

===END ACM DTC None===

===IPC DTC None===
Successful DTC reading, no error codes found

Module: Instrument Panel Control Module

===END IPC DTC None===

 

 

 

[pragmatix]

Once again im learning so much from your misfortune. Thanks 

[Tdci-Peter]

4 hours ago, Dee_82 said:

The ABS lamp is illuminated. The ESP lamp is illuminated. There will be an ESP malfunction warning displayed on the driver information text panel. The EBD Warning Lamp is illuminated. ===END ABS DTC B1B69:16-08===

It does look like the ABS voltage went out of spec., and really upset the car, those three warnings may well have triggered limp mode. No other codes claimed to have lit a warning.

B1B69 does not seem to have returned since that first time, but there are still intermittent ABS errors.

Hard to be sure what is going on, CMDTCs do not go away, and can only be cleared by a system like Forscan. (Continuous Memory DTCs.) So it could be an old code, but something put the car into limp mode, and that is the one one with visible warnings.

 

[Dee_82]

Happened again yesterday, interestingly I noticed a small but noticeable hesitation  under hard acceleration, I wasn't logging the data as it appears this BT adaptor whilst fine most of the time doesn't like recording lots of data, it bombs out quite frequently, in one case causing a weird acceleration problem, (hard acceleration to 3k, change gear, apply acceleration and you had to mash the peddle to the floor to keep it going up) That was shortly after the OBD adaptor bombed out.

So im going to try and get a USB-C to USB adaptor and connect my USB OBD cable to the phone, (its a pain in the ***** using the laptop!)

Anyhow

So I decided to run every single test available on forscan today. 

ABS logged -

Code: U0126 - Lost Communication With SASM

SASM Logged

Code: U0126 - Lost Communication With SASM

PCM Logged

Code: U0126 - Lost Communication With SASM

BCM Logged

Code: U0126 - Lost Communication With SASM

Code: B1029 - Accelerator Pedal Sensor - Signal Amplitude Less Than Minimum

Code: P2127 - Throttle/Pedal Position Sensor/Switch E Circuit Low Input

Code: P060D - Internal Control Module Accelerator Pedal Position Performance

The last 3 BCM errors only crop up under the test, albeit there are some odd irregularities like the spike I showed you the other day.

That SASM error is the one that seems to be consistant and is the one that is always present when it enters limp mode, along with the turbo actuator DTCs.

 

I can read all the PIDs from the SASM, all the sensors appear to work just fine, the CC buttons which are routed via the SASM can sometimes stop working.  Any thoughts on what I can do to test this thing? Im loathed to start replacing stuff (with second hand gear which I wont be able to verify as working) in the hope it will work 😞 

[Dee_82]

Using some ford diagnostic processes, I may have found something.

So the resistance to ground from pin 4 on the OBD port should be less than 2 ohms.

If I open the car and check it against firstly a ground point at the base of the drivers door on the floor by the seat and directly via a separate wire to the battery. I get 20ohms

Now, when the IC and presumably everything else turns off, that resistance drops to less than 1 ohm.

The guide says to check for open circuits if its more than 2ohms but it doesn't mention anything to do with lettingthe car go to sleep or disconnect the battery so im not completely sure what to do with that information!

Anyone fancy checking their own car if the have a few moments?

[Tdci-Peter]

2 hours ago, Dee_82 said:

Now, when the IC and presumably everything else turns off, that resistance drops to less than 1 ohm.

In the situation where the multimeter reads 20 ohm, switch it to voltage range, and see if there is some voltage over the circuit due to current flowing. It may only be a few mV, but it will still be enough to upset a multimeter reading on ohms range.

To do an ohms test, a multimeter energises the external circuit with a rather small voltage and small maximum current. Partly because it is battery powered, so can't put out a lot of power, but also to prevent damage to delicate circuits and avoid turning on most diode & transistor junctions, enabling better results on electronic circuit testing.

So an existing voltage over the circuit being tested will cause a big error in the reading. It has caught me out more than once! Car earth circuits have loads of voltage drops while anything is drawing current. I have seen 100mV or more between my engine and the bodywork, due to currents in the earth wiring.

If possible, always do resistance testing with everything shut down.

[Dee_82]

Well I think I have made some progress and it is adding up

So I disconnected the Ground strap from the body work next to the passenger door (the first of three  towards the engine) G6D139
and did a resistance check to Pin 4 on the DLC. Perfect, absolutely no problem at all.

So with the ground disconnected from the chassis  I ran a wire from the negative terminal on the battery and checked for volts OFF the ground wire directly to the battery.

~4v - Interesting.

So I then did a continuity check between the ground wire (not connected to the body) and all of the fuses in the CJB and I had continuity between  Fuse 2, 3 and 4

 

apart from the SRS (which is a little worrying) that is exactly what im getting trouble with, APP, ABS and the ground itself is directly connected to the DLC and the SASM.

In my mind this cant be a coincidence, can it?

Now, please correct me if im wrong but that suggests that at least one of those three are shorting out in one way or another? the others could be linked else where?

Im going to pull the fuses one at a time and see which one kills the 4v on the ground, that should narrow down the circuit that is I think is causing the bother. 

If you have any thoughts im all ears, I feel like im inches from know what the problem is.... fixing it is a different matter but one thing at a time!

@iantt 

Have you run in to anything similar on your travels?

 

edit, spoke to soon.

 

So pulling fuses didn't help at all and bizarrely everything was joined to the ground, and not just those three, also to note, it was 8V and not 4v this time.  I even tried all the fuses and relays in the engine bay. still the 8v persisted. short of taking the power off the battery or disconnecting the side multi pin plug on the CJB, the 8 volts stayed there. even when I did remove that plug it remained as having 2v on the ground which disappeared when I disconnected the smaller plug on the far side.

 

 

[pragmatix]

No more baffled than i was before.

[Tdci-Peter]

7 hours ago, Dee_82 said:

So pulling fuses didn't help at all and bizarrely everything was joined to the ground, and not just those three, also to note, it was 8V and not 4v this time.  I even tried all the fuses and relays in the engine bay. still the 8v persisted. short of taking the power off the battery or disconnecting the side multi pin plug on the CJB, the 8 volts stayed there. even when I did remove that plug it remained as having 2v on the ground which disappeared when I disconnected the smaller plug on the far side.

When a wire is disconnected, small currents can give all sorts of odd voltages on the wire. Putting the meter on current range and measuring current to the ground might yeild better results, though high currents (like window & door motors) might blow the fuse in the meter.

I do not have a Modeo wiring digram, so can not be sure what will be powered up via what fuse, or via igntion or battery direct. It is quite common for bus connected modules (eg SASM) to be powered from battery direct, so they can do an orderly shut down or self tests when the ignition is turned off.

[Dee_82]

Hey, so I've been doing some revision. 

Apparently volts an a ground is normal when it's not connected by increasing the resistance (DMM) we increase the bottle neck which is what the DMM is recording. I need to check a couple of things but that might be a red herring.

So going back to what I know.

Pin 4 on the obd port is a chassis ground, it connects to G6D139 on the body. There about a hundred things connected to it! With the car awake and asleep I took some resistance checks to a different ground in my car and a mate did the same in his Mondeo

Mine Asleep - 0.9ohms

Mine Awake - 20 ohms

Mates Asleep - 0.04ohms

Mates Awake - 0.14ohms

That's the same numbers when testing the accelerator power ground which uses the same ground point.

That isn't a lot but we are only looking to ever so slightly mess with the sensors.

When testing end to end on that ground wire it's 0.9ohms.

It just doesn't make much sense. What could introduce resistance in a wire and increase / decrease when the car wakes / sleeps 

[Tdci-Peter]

20 minutes ago, Dee_82 said:

What could introduce resistance in a wire and increase / decrease when the car wakes / sleeps

I doubt if the resistance is changing. More likely the current flowing in the earth wire is changing. This will look like a resistance change when a multimeter on ohms range is used.

It looks like there may be more current flowing in that earth wire on your car than on your mate's, so that might just possibly indicate a fault. But first make sure the two tests use the same, or same type, of multimeter. Different meters will respond differently to imposed voltages when in ohms range. Then you can measure the earth current directly by putting the meter on amps range from the earth wire terminal to the earth point. This is not a sure test, meters have a voltage drop ("burden") when measuring amps, that depends on range being used and type of meter. If there are parallel earth paths, most of the current will find an easier route than via your meter.

Unfortunately it is a basic physical fact that no system can ever be measured without interfering with it in some way, and multi-meters do interact with the circuits being measured quite a lot. Voltage ranges all draw a few micro-amps of current, ohms ranges inject voltage & current, and current ranges introduce a voltage drop. It can be a nightmare on sensitive circuits!

[Dee_82]

Hmm, so really I need to get our cars next to one another and use the same meter on them to compare, make sure  its not the meter.

Thats a pain but I can work that out, lets assume for a second that there is a genuine difference and that for some reason more current is passing through that ground.

Could that then bring up errors such as?

Code: B1029 - Accelerator Pedal Sensor - Signal Amplitude Less Than Minimum 

Code: P2127 - Throttle/Pedal Position Sensor/Switch E Circuit Low Input 

Code: P060D - Internal Control Module Accelerator Pedal Position Performance

Perhaps im clutching at straws but it just seems very coincidently that this stuff is all connected to the same ground.

[Dee_82]

So I measured the current on my car from the ground wire to the ground post as well as a direct line to the battery. It was about 1A

I pulled the fuses one by one and it dropped to about 200mA when pulled the cluster fuse.

I happen to have a different Cluster, an older type 1 cluster So I swapped it with the converse+  (you can do that on the Mondeo mk4 without any bother) The current dropped to about 500mA and the resistance from pin 4 to ground dropped to 10 Ohms, the Converse unit probably requires considerably more power which may explain the drop.

It didn't help one bit with the tests, ABS still has a problem with SASM.

The CAN has a resistance of about 60 Ohms between the high and low side (pin 6 and 14) which I believe is about correct, Something I forgot to mention is that although the SASM says no DTCs, when I ran the test it generated the same ABS DTC as what is listed below. In fact running ABS, SASM, PCM and BCM test, all generate the same ABS fault with coms to SASM.

The Throttle peddle DTCs only come on with the BCM test and yet all PIDs can be read from both ABS and SASM. Turning off ESP didn't help with dropping to limp mode

 

===PCM DTC P2127:00-2E===
Code: P2127 - Throttle/Pedal Position Sensor/Switch E Circuit Low Input

Status: 
 - DTC Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Powertrain Control Module

===END PCM DTC P2127:00-2E===

===PCM DTC P060D:00-2F===
Code: P060D - Internal Control Module Accelerator Pedal Position Performance

Status: 
 - DTC Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Powertrain Control Module

===END PCM DTC P060D:00-2F===

===OBDII DTC None===
Successful DTC reading, no error codes found

Module: On Board Diagnostic II

===END OBDII DTC None===

===SASM DTC None===
Successful DTC reading, no error codes found

Module: Steering Angle Sensor Module

===END SASM DTC None===

===ABS DTC U0126:00-8A===
Code: U0126 - Lost Communication With SASM

Status: 
 - DTC Present at Time of Request
 - Malfunction Indicator Lamp is On for this DTC

Module: Antilock braking system

Diagnostic Trouble Code details

There are DTCs for other modules.

Check All Other Modules On The Data Bus For Function And DTCs

Possible causes are:

CAN communication fault

Internal fault in the SASM.

Perform these checks

Check the SASM CAN communication connections.

Check the SASM power supply connections.

Check the SASM for DTCs.

Check the SASM fuses.

Check the wiring for the SASM.

Check the electrical connections for the SASM.

Additional Information

DO NOT replace  the ABS module based on this DTC alone.

Do not replace the ABS module based on this DTC alone, unless a fault or physical damage is found.

The ABS, EBD, TCS and ESP lamps are illuminated.

There will be an ESP malfunction warning displayed on the driver information text panel.

===END ABS DTC U0126:00-8A===

===BCMii DTC None===
Successful DTC reading, no error codes found

Module: Body Control Module

===END BCMii DTC None===

===PDM DTC None===
Successful DTC reading, no error codes found

Module: Passengers Door Control Unit

===END PDM DTC None===

===DDM DTC None===
Successful DTC reading, no error codes found

Module: Drivers Door Module

===END DDM DTC None===

===RCM DTC None===
Successful DTC reading, no error codes found

Module: Restraint Control Module

===END RCM DTC None===

===HVAC DTC None===
Successful DTC reading, no error codes found

Module: Heating Ventilation Air Conditioning

===END HVAC DTC None===

===ACM DTC Error===
Unable to read DTC

Module: Audio Control Module

===END ACM DTC Error===

===IPC DTC None===
Successful DTC reading, no error codes found

Module: Instrument Panel Control Module

===END IPC DTC None===

 

[Tdci-Peter]

3 hours ago, Dee_82 said:

It didn't help one bit with the tests, ABS still has a problem with SASM.

The CAN has a resistance of about 60 Ohms between the high and low side (pin 6 and 14) which I believe is about correct,

Yes, 60ohms is right, it should be close to that when the bus is not powered.

Problems like this can often only be tracked down by elimination. So investigating odd resistances and tracing it to the current drawn by the IC is still a step forward! I assume the current dropped to a much lower value when the IC shut down. 1A would cause enough ground wire voltage drop to give resistance measurement errors. It is probably quite thin wire. Copper is expensive & heavy.

The ABS/SASM fault still stands out as the most probable cause of the limp mode, as it seems to be putting warning lights on. One thought, the error code being in the ABS above, and not in the SASM, suggests to me that the ABS was trying to get data from the SASM, but the SASM was not aware of this, so received no valid request packets. That puts a slight bias to the SASM being at fault, as reception of CAN packets is probably more critical than transmission.

 

 

[Dee_82]

Today I decided to forget work and just concentrate on this... 

 

Checked power at SASM (Pin1) and IC (Pin 32). Both displayed 12.3v to both modules

Checked Current at Power Ground (G6D139) 300mA when off, 500mA when ignition on engine off, 5-10A when blower is engaged. (this is with the old IC in place, the newer one adds about 500mA more.

Checked Current at 2 Grounds on Drivers side (G3D134 and G3D135) both reading 0-100mA, turning to 0 shortly after powered up.

resistance between DLC HS-CAN + and - (Pin 6 and 14) with no power (I didn't turn the power off when I mentioned this yesterday so re tested) 61 Ohms

Resistance between SASM HS-CAN + and - (Pin 4 and 5) with no power, 61 ohms 

Resistance to Power Ground G6D139 from SASM (Pin 14) and IC (Pin 6) 0.3 ohms

Resistance to Power Ground G3D134 From APP (pin 4) 0.7 ohms 

 

So the SASM is getting volts, its grounded via a ground point that is in my opinion getting absolutely hammered (up to 10 amps with the blower on) I have nothing to compare that too just now so it might be normal.

Im still getting the ABS / SASM error when running tests as well as the APP error so since it was cheap I have taken a gamble on a second hand SASM to see if makes any difference at all.

the SASM has a good physical connection to the CAN so unless something is interfering with the signal the SASM might be faulty....

 

 

 

 

 

 

[Dee_82]

Another idea out the window!

So the replacement SASM turned up today, works fine but the problem persists between the ABS and SASM.

Unless ive managed to pick up the a SASM with the exact same problem I know the SASM is good.

I know the HS-CAN loop is good,

I know the link from the HS-CAN to the SASM is good.

I dont know if the connection from the ABS module to the HS-CAN is good.

I dont know If the ABS module is nackard but again, the PIDs all work

I dont know if the data packets are being corrupted or lost in a sea of invalid messages

I dont know what it is the ABS module is asking for so it could be something that is connected to the SASM  but there isnt much that makes sense.(see pic)

The only thing that links the SASM to the other problems is G6D139 power ground (thats the one with 8v 10 amps on it when the blower motor is on) and G3D134 the signal ground.

 

Not sure when ill get a chance to test the ABS to HS-CAN link as thats a PITA to get to.  But if anyone knows if what is going on with that ground is normal im all ears.

 

 

 

[Tdci-Peter]

2 hours ago, Dee_82 said:

I dont know what it is the ABS module is asking for so it could be something that is connected to the SASM  but there isnt much that makes sense.(see pic)

The only thing that links the SASM to the other problems is G6D139 power ground (thats the one with 8v 10 amps on it when the blower motor is on) and G3D134 the signal ground.

Somewhere there is a steering wheel angle sensor. It is usually part of, or adjacent to, the clockspring unit. And as the SASM drawn in the pic includes the clockspring connections, it will likely be in there. The ABS uses steering wheel angle, along with a yaw rate sensor (gyroscope) to do the ESP function.

On the Focus, the heater blower wiring is 4mm^2, which is heavy stuff, and it has a 30A fuse. It may draw 10A on full speed. The ground wire on your pic is 0.5mm^2, not enough for 10A. But Ford have a nasty habit of hiding wiring joints (splices) in the looms, so the heavy blower motor cable might join this wire somewhere between SASM & the ground point. You might be able to tell from the colour code and wire conductor thickness. 0.5mm^2 is under 1mm dia (copper), 4mm^2 is over 2mm dia.

If the blower motor current is supposed to be there, then it makes the earthing resistance more critical. Motor currents are usually quite noisy, brushes and commutators are electrically noisy over a wide bandwidth. Poor earth could then interfere with CAN comms. But I doubt if there is a correlation between running the blower and error codes or limp mode. It might be worth a bit of testing though.

If the blower motor current is not supposed to be there, then it is even more of a problem in that thinner wiring. A poor earth connection on the normal earth point might just do this, and somehow it finds an alternative path to earth. But it sounds a bit unlikely.

Other than this, it does look like suspicion is moving steadily toward the dreaded ABS unit. I bet it is hard to get at, I have not even really seen mine, it is well tucked away.

 

 

[Dee_82]

I replaced the complete SASM, I think ill double check inside the old one and see if I can see the damaged Thermal Fuse which plagued this model of car.

Interestingly the Yaw sensor is connected directly the HS-CAN, it doesn't connect to the SASM at all but it does share a signal Ground with the APP Sensor. 

As for the blower, your correct, the blower does connect between  the SASM and the ground point, its joined by two splices , SP195and SP518, the wire gets heavier as it passes down. Curiously a thought came to me, the previous owner didn't use the fan on anything higher than the first couple of settings which might explain why he didn't experience the problems.... being in Scotland I use it a lot, its not something ive kept an eye on so ill keep it set to its lowest setting and see what happens, turning it off makes no material difference to the tests, albeit I haven't tried testing without the fuse which might be worth a shot as the blower controller is a simple resister connected to the CJB with a signal wire from the HVEC controller, disconnecting that controller just turns the fan on full. Ill give that a go tomorrow. Isolating the HVEC controls first, then the blower fuse

Im in two minds about the ABS, ill test the HS CAN connection but im still drawn to this electrical problem . The IC has an LCD display that looks "Noisy" its not transitioning in a fluid way and it takes second between menus to clear up. The APP peddle response, picked up as a problem by the BCM and occasionally noticeable on traces. the Blower motor and LCD HVEC display can sometimes dim a little in a pulsating pattern.  The Turbo vanes, which move freely until it decides that they aren't. The car can on occasion, normally just after starting stall IF I blip the accelerator, it rises then falls as it hits idle it drops off, no DTCs, restarting no problem. Im actually wondering if the door lock error might have something to do with this as well now since it sometimes locks and sometimes doesn't. 

The loom is probably in the most horrible of all places in a car, its virtually impossible to get to although I might have access to about 1 foot of it behind the head unit if I remove the cage so looking for errors is going to be a challenge 😞

I removed the chassis ground and cleaned it today, resistance is now 0.3 Ohms from the strut tower to the Ground Point G6D139 with the battery disconnected, when connected and ignition off, that resistance increases 1.7 Ohms, thats effectively through the chassis, if I kill the power to the interior lights it drops to 1.3 Ohms, nothing else changes it unless I pull the connector c1bp02-A which is the main connector to the power distribution board (its not the main source of power though, that is two 30A wires on c1bp02-G) when pulling that plug along with the lights and ignition OFF, it drops to about 0.7 Ohms which is more or less the same as everything else.

 

not sure thats useful information or not but hey, it doesn't hurt

 

 

 

[Tdci-Peter]

4 hours ago, Dee_82 said:

The loom is probably in the most horrible of all places in a car, its virtually impossible to get to although I might have access to about 1 foot of it behind the head unit if I remove the cage so looking for errors is going to be a challenge 😞

One way to assist in looking for bad earths, as you have the wiring info, is to measure voltages between earthed points while turning loads on & off.  Voltage between the DLC (OBD) ground pin and either the G6D139 earth or some good contact point near it, would test most of the common earth wiring, through those two big splices. There is normally no current in the DLC wire, so the voltage at the DLC would be the same as the voltage at SP195. The cigar lighter earth is another handy test point, for SP518.

6mm^2 wire has a resistance of under 0.003 ohms per metre, so should be small. Maybe 30mV at 10A & 1 metre. 1.5mm^2 wire has a resistance of about 0.012 ohm per metre, That's 12mV at 1A and 1m. That gives some very rough guidance for voltage drops to be expected. Measuring currents and estimating lengths as best you can would refine it a bit.

Much higher voltage drops might indicate a bad splice. If you do not want to rip out the looms behind the facsia (who would!), an additional heavy earth cable could be added, say from the 4mm^2 wiring to the heating control head / blower module, if that is accessible, to a handy bit of decent bodywork.

 

[Dee_82]

18 hours ago, Tdci-Peter said:

One way to assist in looking for bad earths, as you have the wiring info, is to measure voltages between earthed points while turning loads on & off.  Voltage between the DLC (OBD) ground pin and either the G6D139 earth or some good contact point near it, would test most of the common earth wiring, through those two big splices. There is normally no current in the DLC wire, so the voltage at the DLC would be the same as the voltage at SP195. The cigar lighter earth is another handy test point, for SP518.

6mm^2 wire has a resistance of under 0.003 ohms per metre, so should be small. Maybe 30mV at 10A & 1 metre. 1.5mm^2 wire has a resistance of about 0.012 ohm per metre, That's 12mV at 1A and 1m. That gives some very rough guidance for voltage drops to be expected. Measuring currents and estimating lengths as best you can would refine it a bit.

Much higher voltage drops might indicate a bad splice. If you do not want to rip out the looms behind the facsia (who would!), an additional heavy earth cable could be added, say from the 4mm^2 wiring to the heating control head / blower module, if that is accessible, to a handy bit of decent bodywork.

 

So rather than write this out I thought id enlist the aid of Excel.

This is all measured from what I think is the signal Ground on the drivers side, I need to double check that. The current ratings are from the G6D139 Power Ground, I connected between the wire and the correct grounding point, was getting a little curious when I hit 17Amps, my meter is only rated to 20! 

Everything apart from that last set of data with the fan on against the ground point is right. im going to go double check that but its getting to dark for faffing around in the road so it will need to wait.

If it is right, then we are still getting 60 ohms of resistance between two chassis ground points but only under heavy load. 

That sound about right to you?!