PATS error code 16 - 56 Reg Mk2 Focus

[LTIronWolf]

Big news! I figured out what was causing the intermittent 1:6 problem, where the car would seem to alternate between cranking and going back to the 1:6 error - the fault lied in the connection on the PCM harness. There's a good chance this is what caused this problem in the first place and why I made this thread.

The problem/solution is this - the harness wasn't making sufficient contact where it needed to, so therefore the IC actually couldn't see the PCM because there wasn't a good enough connection when the harness was plugged in. I discovered this after rocking the connection about on the harness, and realised that certain "orientations" of the plug yielded different results. When the plug was swivelled towards the engine as shown in Fig. 1, the PCM and IC could successfully communicate and you could hear the fuel pump priming. When the connector was swivelled as shown in Fig. 2, the car would still crank but you couldn't hear the fuel pump priming. When the connector was oriented as shown in Fig. 3, the car would regress back to its 1:6 communication error and wouldn't work. 

In summary, if you are getting a 1:6 error on your Ford Focus - check the connection on your PCM harness! It sounds obvious and stupid, I know. (Assuming you've run through the other tests like checking the fuses, doing the resistance test on the OBDII port, reflowing your IC, etc.)

This led me to think - if it's just a contact issue, maybe my original PCM still works? I thought I'd give it a try and I swapped back in my PCM. This time round, I managed to knock the shearing bolt (using a hammer and chisel) to the point where it was completely flush with the PCM and there wasn't any play in the harness - it's like I never took the PCM off in the first place. I connected to the original PCM using FORScan, and sure enough - it worked. It has a few DTCs but nothing too worrying - most are triggered by the mismatched IC and PCM, which I'll reprogram soon.

So the current configuration is as follows:

• PCM - Original
• IC - Replacement
• Transponder - Replacement + original blade

Now in terms of the keys: I've got two fobs, the original and replacement, and I've got the original blade. I've ordered a blank blade off the internet which I'm waiting to arrive and I'm going to take it to an independent key cutter to get it cut to the original key (Timpson won't go anywhere near car key copying, or cutting a supplied blade - you have to buy a complete key off them if you want them to do anything) so that way I'll have two keys - the screwdriver release on the new fob is worn out, so I can't get the blade off. Regardless, I'm waiting for the new blade so I have two keys and that way I can do PATS programming. At the moment, it looks like it's just a case of reprogramming the IC and we're good to go!

Fig. 1 - Correct orientation on the harness (pictured above)

Fig. 2 - Incorrect orientation (pictured above)

Fig. 3 - Non-working orientation (pictured below)

[LTIronWolf]

One more thing - does anyone know if it's possible to re-use 2nd hand fobs for the sake of programming PATS keys? I have the original fob that's programmed to my original PCM which is currently in the car, and then I have the replacement fob that came with the new PCM and cluster that's currently installed.

The replacement key is currently programmed to a different PCM, but it's an OEM key - can it be reprogrammed as if it were a blank key? I'm waiting on a blank blade so I can get it cut and then have two keys, seeing as I need two when I initialize the cluster using FORScan.

[Tdci-Peter]

4 hours ago, LTIronWolf said:

The replacement key is currently programmed to a different PCM, but it's an OEM key - can it be reprogrammed as if it were a blank key?

When Forscan is used to add keys, it does not programme the key. That usually has a fixed code built in. It programmes the car to accept the key. Adding keys is relatively safe, it should not disable any existing keys.

It must generally be possible to re-use a key. If a key is stolen, and needs to be removed from the car's memory, the only way to do this is to erase all keys, then add all your existing keys back in. As the car will not remember whether they were used with this car before, or are new, or are from another car, it should accept all, as long as they are the right type.

There are procedures on the Forscan website to check whether a key is the right type, basically just trying it in the ignition, then reading the error code if any. A right sort of key, but not programmed in this car will give a different error code to the wrong type of key that can not be recognised.

One possible big pitfall is cloned keys. Many locksmiths and some internet sites will make you a working key, coded for your PATS, if you give them an existing working key. Certain non-OEM keys are re-programmable, and special equipment can copy the code from one key into another. This method will not yield the two keys needed after a key erase procedure. They will read as the same key.

The original key and the replacement key from the other PCM will have two different codes, they will not be clones of each other. So that should not be a worry here. But it can be a problem in other circumstances.

[Botus]

I hope I helped... ? as in encouraged you to check the order / double check were you are when you swap out stuff.

So now at the page of origin PCM and still need to get the new cluster linked up.... ?    you seem happy to get stuck in and use FORscan… I expect with a good tutorials flashing the cluster will be easy.  (Make sure the key transponder is the one you need for which other bits you are trying)

[LTIronWolf]

On 7/10/2018 at 9:30 PM, Botus said:

So now at the page of origin PCM and still need to get the new cluster linked up.... ?    you seem happy to get stuck in and use FORscan… I expect with a good tutorials flashing the cluster will be easy.  (Make sure the key transponder is the one you need for which other bits you are trying)

The transponder doesn't matter too much, if at all - when you initialize the PCM or IC using FORScan, you have to erase all keys from memory and reprogram them. In the meanwhile, I'm still waiting for my blank blade to arrive so I can get it cut and get my car programmed.

[LTIronWolf]

Blank key blade arrived and I got it cut - all that’s left is to verify that both keys will work, and then it’s off to program the IC with FORScan. Fingers crossed it works!

[LTIronWolf]

And she’s alive! The replacement fob was a bit iffy at first and didn’t seem to program when programming additional ignition keys with FORScan. However, after erasing all keys and initializing the car with FORScan, she starts back up just fine - just like all those months ago before she first broke! I checked for any DTCs after everything fired up, and it’s completely clear.

Now my only question is this - the mileage is about 15k higher than it should be, and the car is currently missing its bonnet lock as it’s broken and I’n waiting for a new one. Would either of these cause a fail or advisory in the MOT?

[Botus]

bonnet lock will fail....  no one gives a stuff about mileage…. except u may when new MOT validates your mileage as 15 more than real

[LTIronWolf]

@Tdci-Peter Hello, me again!

1:6 error has returned, after the car was parked for a month untouched. I’ve checked all the fuses (with no breaks) and also disconnected + reconnected the battery to no success. I can’t connect using OBDII, however the PCM is still firmly plugged in (which was the culprit last time) and the car still primes. The secret menu displays U1900 and U2510. I have no idea what’s caused the upset - only thing that’s happened is the battery drained after sitting for month, and I went to run the car just to let it charge up when I realised the error happened.

[Tdci-Peter]

14 hours ago, LTIronWolf said:

1:6 error has returned, after the car was parked for a month untouched. I’ve checked all the fuses (with no breaks) and also disconnected + reconnected the battery to no success. I can’t connect using OBDII, however the PCM is still firmly plugged in (which was the culprit last time) and the car still primes. The secret menu displays U1900 and U2510

Sad to hear that.

The IC menu codes are kind of useful in just confirming the connection problem to the PCM.

I was a bit concerned last time about attacking the bolt with hammer & chisel! I think I would have tried to get the plug(s) fully removed to inspect them, then replaced the bolt with a proper one with a head, somehow. As moving things about in this area cured the problem before, it is the prime place to look.

Re-check the CAN bus resistance a few times, then if the bus is ok, I guess it must be a bad connection to one of the several power or ground lines to the PCM. Could be in the plug, or in the wires near the plug. Or even a bad joint inside the PCM. Locating this sort of fault is a real pain, as I know all too well. I have spent lots of time bending and feeling wires to try to replicate or cure faults.

I just re-looked at your Fig 1 photo above, of the plug. It looks like it has to be canted at an angle to make full contact. This strongly suggests a contact pin or wiring connection fault in the plug.

If there is any evidence that the cable or plug is at fault, second hand harnesses are available on eBay & other places. Though you have to be careful to identify exactly the right one for your year and engine type.

[LTIronWolf]

On 8/24/2018 at 11:21 AM, Tdci-Peter said:

Re-check the CAN bus resistance a few times, then if the bus is ok, I guess it must be a bad connection to one of the several power or ground lines to the PCM. Could be in the plug, or in the wires near the plug. Or even a bad joint inside the PCM. Locating this sort of fault is a real pain, as I know all too well. I have spent lots of time bending and feeling wires to try to replicate or cure faults.

I just re-looked at your Fig 1 photo above, of the plug. It looks like it has to be canted at an angle to make full contact. This strongly suggests a contact pin or wiring connection fault in the plug.

If there is any evidence that the cable or plug is at fault, second hand harnesses are available on Ebay & other places. Though you have to be careful to identify exactly the right one for your year and engine type.

Did a resistance test on the CAN bus: this time it was 120 ohms, so there doesn't seem to be continuation. However I tested it again and this time it's anywhere from 30-60, and then back to 0 ohms so it appears it's a CAN bus issue although I don't know how it could've happened.

The only thing that's happened since I first fixed the car to now is that the bonnet on my car flew open and slammed into the windshield, to which I had to replace the windshield and both front fenders. I don't know if this would have any effect on the CAN bus as I didn't notice any visible damage to any wiring (except for the wiring by the hinge which goes to either the windscreen or the washer fluid jets) or anywhere else. Could the condition of the cluster affect the continuity? I'm thinking maybe I need to re-flow the IC again or replace it for yet another one.

[Tdci-Peter]

1 hour ago, LTIronWolf said:

Did a resistance test on the CAN bus: this time it was 120 ohms, so there doesn't seem to be continuation. However I tested it again and this time it's anywhere from 30-60, and then back to 0 ohms so it appears it's a CAN bus issue although I don't know how it could've happened.

The readings below 60 ohms are a bit odd. Was this done sufficient time after ignition off? The CAN bus remains live for 10 to 30 seconds after ignition off, while the ECU does various tests. This will corrupt any meter readings. Measuring the voltage between the CAN bus lines is an indicator, it drops to zero when the ECU shuts down.

If the low readings below 60 can be repeated, then that suggests a wiring problem in a harness, where it has been crushed or trapped, both breaking one or more wires, and shorting wires together. The CAN bus wires are thin and twisted together, so may be more vulnerable to this.

If you can get stable readings of 120, then disconnect the big plug in the engine bay fuse box. If the reading goes very high, then the problem is in the IC, or in the wiring between IC & fusebox. If it stays the same, then the problem is on the ECU side of the fusebox.

There are no CAN bus wires near the windscreen, or the front wings. So it is hard to see a connection with the bonnet problem. Bit of a nasty thing to happen though.

[LTIronWolf]

@Tdci-Peter Problem fixed - somehow the connector on the back of the cluster came loose, so it wasn’t making proper contact. All is right with the car again, with no other issues.

[martin828]

Hi, I’ve got a 2006 Ford Focus Diesel Estate with a rapidly flashing PATS LED on the Instrument Cluster which, [eventually] changes to indicate the 1:6 code – i.e. lost-communication between IC and PCM. I’ve read-up about the britleizing of the multi-pin connector on the PCB and yes, there were definite cracks in the solder around the pin/pad juncture. Anyway, I’m very competent in electronic circuity (having worked at Thorn EMI Defence Electronics & British Aerospace) so I’ve re-soldered the multi-pin socket on the PCB, but the PATS still shows a rapidly flashing LED and the 1:6 code.

I refitted the Instrument Cluster and put it into test mode and it all checks-out OK, but the PATS LED still rapidly flashes (& the 1:6 code) and the LCD just goes-back to showing - - - - - - - - where the mileage and trip figures should be.

I've also just tried the Ohm-test of pins 6 & 14 of the OBDII connector, I'm seeing 120 ohms so there a part of the CAN-circuit missing as detected in the 1:6 code.  I've unplugged the multiplug in the fuse box and I'm still seeing 120 Ohms, so where do I look now.  Where do I find that big black connector seen in a previous posting?? 

I look forward to hearing from you.

[Tdci-Peter]

On 11/30/2018 at 1:18 PM, martin828 said:

I've unplugged the multiplug in the fuse box and I'm still seeing 120 Ohms, so where do I look now.

There are two more connectors in the CAN bus from IC to PCM. They are both low down just in front of the passenger front door. Unscrew & remove the trim at the bottom of the door, then the trim in front of the door should unclip, and expose 3 large connectors. Two of these (C113 & C112, but I am not sure which is which!) carry the CAN bus. A twisted pair that is Gy-Rd & Bu-Rd will be the HS CAN bus.

Also I found I had to use Forscan to reset a CMDTC (continuous memory DTC) after fixing my IC, a basic OBD scanner would not do it. But this has nothing to do with the 120 ohm problem, your 120 ohms means the HS CAN is broken somewhere between the DLC (OBD socket) and the PCM.

The pin numbers on the Engine fusebox connector (C90) are 1 & 15 for the CAN bus, same coloured twisted pair as above. Continuity testing these could check if you have continuity to the PCM from there.

A possible layout for C90 is attached, though I have not verified it.

 

Edited November 11, 2023 by Tdci-Peter
Update Image

[martin828]

Thank you Peter, that's really useful; I'll check these out tomorrow.  As confirmation, I plugged back in the Fusebox connector (C90) and disconnected the IC multiplug, then checked the resistance of pins 6-to-14 of the OBDII connector to reveal open circuit, so this verifies the IC is OK.

When I used my OBDII scanner to read any codes it wouldn't connect; it kept saying "Make sure the ignition is turned-on and re-run diagnostics".  I haven't purchased a FORScan yet, is it worth me getting one, they don't seem too expensive to buy.  

Do you think the PCM could be at fault (there may not be a break in the CAN-bus)??  Is there anywhere I can take the PCM to for a diagnostic check.  I live in Salisbury...

[Tdci-Peter]

1 hour ago, martin828 said:

I haven't purchased a FORScan yet, is it worth me getting one, they don't seem too expensive to buy.  

If you have a Ford, an ELM327 & Forscan are always worth having! USB ELMs are more reliable, and more capable with large or critical data transfers, then BT or WiFi. The "modified" ELM gives access to the BCM (GEM or passenger fuse box), door modules, audio and other stuff, as well the the stuff on the HS-CAN bus. I can give links to ELMs & other stuff. Get Forscan direct from forscan.org, not from any dodgy intermediary.

Forscan will not connect if it can not find the PCM, very few systems will, I think Ford IDS and Snap-On systems might be able to link to other modules first.

Removing the PCM is not dead easy, there is a security bolt to drill or grind off. If the PCM was removed you could test for the 120ohm resistor direct at its pins, I can post the pin-out, but need the engine type (1.6/1.8/2). But the Engine bay fuse box is the next connector in the line, close to the PCM. The full schematics for the Mk2 (&Mk3) Focus are on this site:

I hope it is not the PCM. There are places offering to repair them, but I have no experience of them. Loss of the 120ohms can only be a wire, connector, track or solder fault, it should be directly between the CAN lines as a terminating resistor, not via any chips or other components.

[martin828]

That's all good stuff; I've got the PCM off the car (had to grind-off the shear-bolt, but I'll put a normal bolt and spacer back in when/if I get the car working again).  My PCM has the (3) connectors at the base (under that metal shield), it's a Mk2 Focus, 2007 1.8 TD - I'd be interested to know which pins output the 120-ohm resistor so I can check for its presence.  I'll also plug it back into the car and check the pins (1-to-15) of the fuse-box (C90) connector to check for continuity.  

I've seen the FORScan web page but I can't see on there where to purchase them from.  Bearing in mind my OBDII can't detect a connection will a FORScan be able to??  I have a "Formidible" program which cannot connect either.

[Tdci-Peter]

4 hours ago, martin828 said:

Mk2 Focus, 2007 1.8 TD - I'd be interested to know which pins output the 120-ohm resistor

HS-CAN should be pins A3 & A4 on C418. Faceview of C418 below. C418 is the smaller of the 3.

Forscan software for WIndows is free download, and is the most capable version. Apps for IoS & Android are available via links on the Forscan site for a small charge, but are a little more limited. All versions need an ELM327 adapter, preferably a "modified" one which gives access to the MS-CAN bus also, and preferably one that is warranted to work with Forscan. ELMs are all clones, and quality is rather hit & miss. There is an interesting (to some ) article in Wikipedia about the ELM327.

Forscan site is: http://forscan.org/download.html

There are loads & loads of ELM327s out there, one supplier of Forscan tested ELMs is:

https://tunnelrat-electronics.fwscart.com/

But it will not connect if the CAN bus to the PCM is broken, or if the PCM is broken. Forscan tries to get critical information from the PCM about the car before it does anything else.

 

[martin828]

Grateful for the info: I've just checked pins A3 to A4 and there's no 120 ohms present, just open circuit, can I assume then that the PCM is dead.  Will a PCM from a different car need to be de-programmed/re-programmed - are they dedicated to the PATS/immobiliser system??  Do you know of any trustworthy service that can repair PCMs; I've read-up on horror stories of repair agencies that take-in ECUs never to be seen again - repair agency and/or ECU.  It'd be a shame to scrap the car just for the sake of a open circuit in the PCM, and the cost of a 2p resistor on the PCM PCB [somewhere].  I'd like to open-up the PCU (bend the tabs back on the back-plate) to look inside, but that is a one-way trip; no repair agency would then look at the PCM/ECU if it's been tampered with.  Grrr, this is so annoying..... 

[Tdci-Peter]

8 hours ago, martin828 said:

I've just checked pins A3 to A4 and there's no 120 ohms present, just open circuit, can I assume then that the PCM is dead.  Will a PCM from a different car need to be de-programmed/re-programmed - are they dedicated to the PATS/immobiliser system??

Have you double checked the wiring colour on the connector on the harness match expectations, or just check resistance back through the harness to the 120ohm in the IC to verify we have got the correct pins. The wiring schematics are not 100% correct, they are pretty good but with something like this it is worth a double check.

The PCM certainly does contain PATS codes, and some other info like VIN. It is possible to re-programme PATS using Forscan, and maybe adjust the VIN with Forscan or ELMConfig, but it is not something I have done. Maybe buying a cheapish, near identical PCM off eBay and having a play with it is one option. You have nothing to lose apart from the cost of the PCM, and some time(!) if it all goes wrong and ruins the unit.

I must admit, in this case since the primary fault is very basic, as an electronics engineer I don't think I could resist pulling the PCM apart. The trouble could be that the the missing 120ohm could be just part of a bigger problem, like water ingress corroding multiple tracks and damaging ICs.

One repair service to avoid and also one recommended by someone is in:

One other recommendation, which was for cluster repairs, but they also seem to do ECUs:

 

[martin828]

All fixed now - I refitted and plugged-in the PCM to check for the 120-ohm resistance at the Fuse-box connector (C90), and hey presto it was there - pins 1 & 15, checked the corresponding socket and again 120-ohms, so I connected the two.  Checked Diagnostic socket and 60-ohms - whoppee.  Turned ignition back on and still no joy - non-start, but rapidly flashing PATS LED and the 1:6 code.  Anyway, by lunchtime the amazon delivery van dropped off my ELM327 interface, downloaded the FORScan software onto the laptop - and plugged the ELM327 into car.  Countless number of error codes, so I erased all DTC's.  PATS LED not flashing now and numerals in the Odometer instead of - - - - - - - - - so I turned the key and Vrooom, she started.  Deep joy.  What can I say, but many thanks to Tcdi-Peter for his wealth of knowledge, and FORScan.  I got the USB interface with the switchable CAN-bus; £20 well spent.  

[deluxor]

I would borrow this topic if i can. I have a Ford Focus 2008 2.0 tdci. Car wont start. Symptoms are if car stays disconnected from the battery over night it cranks but wont start. After 2 or 3 attemps it wont crank anymore and cluster displays code 16 via red light. Before i could connect via obd but now it wont communicate anymore, via IC i get errors a103 d900 e510, it also shows engine malf, tran malf, power steering malf. I checked IC and soldered all pins for broken joints, i checked 3 grounds in engine bay and cleaned them (below battery box, on front shock housing and in front of front left wheel where ECU is located. I also cleaned 2 grounds on front left drivers side (left hand drive). I checked all fuses on gem module and cleaned with contact spray, did the same for front fuse box.

I found this topic today and decieded to do contiunity test on obd between pins 6 and 14, it showed 120 ohms. I unplugged front box connector and still 120, then i unpluged connector in cabin bottom front left (green one) and it showed 60 ohms. I than pluged everything back together and i now the reading is 60 ohms. 

I have no clue what to do, kindly asking for help.

Best regards, Luka

[Tdci-Peter]

1 hour ago, deluxor said:

decieded to do contiunity test on obd between pins 6 and 14, it showed 120 ohms. I unplugged front box connector and still 120, then i unpluged connector in cabin bottom front left (green one) and it showed 60 ohms. I than pluged everything back together and i now the reading is 60 ohms. 

120 ohms is the reading for a broken bus. So with 120 it is likely that Forscan will not connect, at least not if the break is between the obd and the ECU.

60 ohm is the correct reading. Hopefully Forscan will connect if it stays at 60ohms.

There are three connectors down under the passenger side door trims. I suspect if you have LHD, the BCM (passenger fuse box) and the 3 connectors will be on the right (passenger side). The HS-CAN bus goes through 2 of those connectors, one of which is quite a lot higher up, nearer the top door hinge.

I do not know what the colours are, unfortunately. Look for the grey/red & blue/red twisted pairs of wires, on pins 11 & 12 on C112, and pins 17 &18 on C113.

It sounds like your investigations temporarily cured a bad contact in one of the connectors. This happens very frequently when dealing with intermittent faults, and can be very misleading. I have been sent on a wild goose chase many times!. The CAN bus can not read 60 ohms if either one of C113 or C112 is removed, it can only read 120ohms or more. Unplugging a connector that is in the bus must make the resistance rise.

From the fact that it read 120ohms with or without the engine bay fusebox connector in place tell me that the IC connections are ok, and the problem is between the OBD and the ECU. Which is where both C112 and C113 are.

A rather small image of the locations on a RHD car is below. C113 is the higher one, and C112 the lowest, at 45 deg. They should be on the other (still passenger) side on a LHD car. I can also post pin-outs of the connectors if needed.

[deluxor]

hi, thanks for your reply. c112 was the connector which helped when unpluging and pluging back. i have to check c113 in the morning. any other sugestions maybe? best regards, Luka