focus mk2 error code 16 help!

[broken ford]

apologies if this request is in the wrong place.

I need help to sort, error code 16

Car is a focus mk2 1.8tdci 2006, went to start it a few days ago, started fine, was reversing up the driveway when it just went to tickover, lost the throttle connection somehow. The car was idling but would not rev so I thought turn it off and let the electrics reset. It would not start, the red light in the middle of the dash was flashing, I found out this is the immobiliser light, I read on this forum on how to read the code from this, it is 16.

I pulled and checked every fuse engine bay and inside, all good, checked all relays were seated fine, no corrosion in any pins, un/replugged the connectors in the passenger footwell, ign switch and others I could find. I checked and got 60 ohm resistance across the pins (think it was 16, 17 or such)  in the obd2 connector. I had the battery disconnected for hours, no change.

Following forum info I removed the instrument cluster and seen a few cracked pins for the multi block, mostly the top 4 and bottom two, I soldered those and all others looked good, refitted, no change, still 16 flashes.

I am truly lost now, what do I turn to next? I only ever got one key with the car, it is the first time this happened, it has been reliable for years.

Could it be a key, and the transponder ring around the lock? I have removed that as I read the pins should be soldered but I am unsure how to open it.

How could a key go faulty? are there any further checks I can do? This is my main car, I would really appreciate any advice.

 

I

[Tdci-Peter]

On 9/4/2019 at 10:12 AM, broken ford said:

I checked and got 60 ohm resistance across the pins (think it was 16, 17 or such)  in the obd2 connector. I had the battery disconnected for hours, no change.

Following forum info I removed the instrument cluster and seen a few cracked pins for the multi block, mostly the top 4 and bottom two, I soldered those and all others looked good, refitted, no change, still 16 flashes.

I am truly lost now, what do I turn to next? I only ever got one key with the car, it is the first time this happened, it has been reliable for years.

Could it be a key, and the transponder ring around the lock? I have removed that as I read the pins should be soldered but I am unsure how to open it.

From your PM, you have been getting 60ohms and 120ohms intermittently between pins 6 & 14 of the OBD. This is just what I had initially, and stacks up with a bad contact in the HS-CAN bus wires. Thumping the fascia could make it change, though mostly to the wrong value (120). It should be near 60, and rock solid (while the ignition is off).

Code 16 does not stack up with key or transponder ring faults, it is specifically for communication failures.The IC & PCM need to communicate over the HS-CAN bus to identify and accept a valid key.

I had to use Forscan to reset some permanent DTCs (CMDTCs) after I fixed the fault before it would start. Theft related DTCs tend to stay active once set, until cleared by a suitable system.

The PCM is, as Isetta said, in the left wheel arch. But the connectors are locked on to the PCM by a cover with a headless security bolt that has to be ground or drilled out. So testing circuits here is not so easy!

The C90 connector, which is the big connector in the middle of the engine bay fuse box, carries almost all the ECU wiring, so is a good place to test from.

Pins 1 & 15 on C90 are the HS-CAN bus.

Note: With C90 removed, the bus should read 120ohms in each direction (from the plug & from the socket). There is a 120 ohm terminating resistor at each end (PCM & IC), and it will only read 60 ohms when both ends are connected, ie all connectors are in and making contact.

Another view of C90 is below, as the above image may not be very visible.

[Tdci-Peter]

12 hours ago, broken ford said:

seen a few cracked pins for the multi block, mostly the top 4 and bottom two

The HS-CAN bus is two pins at one end. In the photo here, it is the two pins nearest to C19 & C21. R242 and R244 are two 60 ohm resistors, wired in series on the pcb to form the 120 ohm terminating resistor.

To resolder a pin, it ideally needs the old solder removing (sucker or wick), and fresh, cored solder used to make the joint. If the pin is corroded, remove the solder, scrape the pin with a scalpel, then try re-soldering. It can be quite easy to hide a bad joint with a ball of solder.

[broken ford]

Thank you Peter,

I am waiting delivery on an obd2 scanner you had recommended to another user previously, I have downloaded the forscan software and will use that but the older osb2 scanner gives a no link warning, I expect the new one to do the same, Do I need to get to the PCM connections first to make the obd2 port work?

I had soldered (more than) those two connections, I could still have a bad conection there and will check after using the forscan software to reset any faults.

I have the IC plugged in but just laing on top of the steering wheel so I was able to pressure the connection block around to see if I could make any change but it did not affect anything making me think the IC was ok.

, thank you again.

[Tdci-Peter]

10 hours ago, broken ford said:

Do I need to get to the PCM connections first to make the obd2 port work?

Yes, Forscan needs to connect to and identify the PCM before it will do anything. With the IC unplugged, you should get 120ohms (rock solid reading) at pins 6-14 of the OBD. I have posted quite recently about locating the other connectors between the OBD and the PCM, C112, C113 and C90. I will find a link later. For C112 & C113:

[broken ford]

Took the IC out again to re solder the connections i made last time.

Removed the old, looked good and re soldered. I then test fitted just the circuit board in the car but still got code 16. Checked the obd2 pins 6 and 14 and still got 120 ohms.

My new OBD2 and forscan software failed to connect.

I have just tested the pins 17 and 18 that connect to the terminal resistors rz44 and rz42, I got 60 ohms to each and 120 ohms accross pins 17/18.

Does that mean the IC is good? Cant see any other cracks  but there could be some faulty compnent I can,t check. Maybe time to refit that and rule that out?

I tested the obd2 pins 6/14 with IC connected and disconnected, still 120 ohms

What is the next step to get the obd2 working and connecting, the PCM connections?

[Tdci-Peter]

1 hour ago, broken ford said:

120 ohms accross pins 17/18.

Does that mean the IC is good? Cant see any other cracks  but there could be some faulty compnent I can,t check. Maybe time to refit that and rule that out?

I tested the obd2 pins 6/14 with IC connected and disconnected, still 120 ohms

Before checking wiring to the PCM, there is an inconsistency in the sentences I have quoted.

120 ohms direct across 17/18 on the IC pcb (unplugged from car) would be correct for a working IC. If it was plugged in to the car, then 120 would be wrong, but the error could be either end or anywhere in between.

However, if the OBD reads 120 ohms both with the IC plugged in and unplugged, then the fault must be between the OBD and the IC. The 120ohm reading must be due to the PCM being connected if it is taken while the IC is unplugged.

Try repeating this test with C90 disconnected (the one in the engine bay fuse box).

With both C90 and the IC unplugged, I would expect a high reading (well over 120 ohms), because both ends of the bus are now missing from the main part of the bus where the OBD is.

If unplugging & plugging in C90 makes no difference to the reading, then the fault is between OBD & PCM.

If unplugging & plugging in the IC makes no difference to the reading, then the fault is between OBD & IC.

If readings are inconsistent, it is always worth repeating them. These electrical gremlins can be intermittent, and seem to all too often change just at the critical times that will cause maximum confusion. I have been round loops like that many times!

[broken ford]

Hi Brian,

Done a quick test this morning,

Re-soldered(again) IC connected, test pins 6/14 at OBD, 120 ohm, disconnect IC, 120 ohm. Leave IC disconnected and also disconnect C90, 120 ohm. Connect C90 120 ohm (IC still disconnected) re connect IC, 120 ohm. If IC and C90 are connected or not I get 120 ohm.

Not sure where to look next, I think the IC is working fine according to the resistance tests I carried out on the board last night, I can get 60 ohm to each resistor from pins 17/18 or 120 ohm across 17/18.

I was getting 60 ohm at the obd a few days ago, no idea what is going on now. I can't get the OBD2 tester and Forscan to work, it says it can see the switch type ELM and a com port but then says no vehicle found, turn on ignition (it is on) I tried the switch both ways, no difference.

What should be the next step?

[Tdci-Peter]

2 hours ago, broken ford said:

Re-soldered(again) IC connected, test pins 6/14 at OBD, 120 ohm, disconnect IC, 120 ohm. Leave IC disconnected and also disconnect C90, 120 ohm. Connect C90 120 ohm (IC still disconnected) re connect IC, 120 ohm. If IC and C90 are connected or not I get 120 ohm.

It it looking to me like this is a long term fault, and someone has done some sort of modification to try to solve it. Something like soldering a 120ohm resistor across the CAN bus somewhere, maybe at the OBD socket itself. Or maybe C90 has been by-passed by some added wires, but this is quite difficult as it needs access to the ECU connectors, and it does not explain the failure to connect to the ECU. My ELM & Forscan was able to connect to the ECU even when the IC was broken, so the CAN bus resistance was 120ohms.

Tracing continuity through individual wires is the next logical step.

Pin 6 on the OBD goes to pin 18 on the IC.

Pin 14 on the OBD goes to pin 17 on the IC.

Pin 6 on the OBD goes to pin 15 on C90.

Pin 14 on the OBD goes to pin 1 on C90.

You will need an extension wire to do a continuity check from the OBD to C90, as the meter leads won't reach, I guess. I can't see for sure which part of C90 goes to the ECU, bundles of wires from both sides head in that direction.

Between the OBD & C90, the bus also passes through C112 and C113, these are behind the trim below and in front of the passenger door. Photo above. I can get pin nos and connector views if needed.

I would be tempted to remove the OBD connector, and have a look at it. Something odd is going on somewhere around there, if you get 120 ohms with both ends of the bus either disconnected or connected.

[broken ford]

just doing more testing, checked continuity from the obd to the IC socket, good on both pins, cant yet check to the C90.

Getting 120 ohm with IC connected and zero with it disconnected (C90 connected) C90 disconnected, still get 120.

Do you think I need to get to the PCM now?

Will check the passenger side panel connections and passenger fuse box again. Engine fuse box all good

[broken ford]

dug out the PCM, 3 connector plugs, all in good condition inside, no sign of any corrosion or water entry.

TESTS:

IC +PCM disconnected = 0

IC discon +PCM con =0

IC con +PCM discon =120 ohm

IC + PCM connected = 120 ohm

Is there anything that can be done now?

Getting ready to smash the car up and call the scrap dealer to remove, I can't believe how impossible this seems

 

 

 

[isetta]

I had a lengthy post on here about my brother’s focus 1.8tdci. I ended up rewiring the two canbus wires from ic via obd socket, abs,esp, elec power steering motor to Ecu. All joints soldered to reduce dodgy connections. To see if it works you could temporarily splice wires into the canbus wires by ic, run them out the window and splice to canbus wires next to ecu. Of course it will have error codes for abs and maybe more but if car runs right then you know it’s a connector somewhere or break in wire and it might give you renewed hope

[broken ford]

Thanks Isetta,

Good idea, I will give that a go, if I can get the OBD working I could maybe clear some faults.

There are three connector blocks on the PCM, I have no idea which block would have the can bus wires 😐

I noticed that the glow plug light does no longer comes on when the ignition is on yet it displays ok with the IC gauge test.

Been working on cars and bikes for decades and never been so frustrated but I appreciate all the helpful advice on here

 

[isetta]

Peters message 8 hrs ago mentions PIN numbers for canbus wires. I am pretty sure the wires are blue/red and blue/white. And the wires are thinner than a lot of other wires around them.  They are thin as they don’t carry any real current that powers anything. They carry pulses of computer data. Until I had all this hassle sorting out my brother’s car I did not realise how complicated and frustrating these things had become. What I have said is based on 2008 mk2.5 1.8tdci

[Tdci-Peter]

3 hours ago, broken ford said:

IC +PCM disconnected = 0

IC discon +PCM con =0

IC con +PCM discon =120 ohm

IC + PCM connected = 120 ohm

I am assuming that 0 is overload, ie high resistance, the same as if the meter leads are not connected to anything.

If so, those readings show a broken wire or connection between the OBD and the PCM. The most likely culprits will be the two connectors C112 & C113, pictured several posts above. The picture is small, but C113 is the one at the front centre, a bit under the dashboard. C112 is the low down one at an angle.

But there is also quite a bit of wiring inside the car, it seems to loop back to under the rear seat in between C112 & C113. This will be for the additive module used on a 1.6TDCI, but the same harness may be used on the 1.8TDCI.

The order of stuff on the CAN bus is: IC, OBD, C112, loop to back seat (possibly), C113, through the bulkhead, ABS, Steering, C90, PCM.

The CAN bus is a really terrible system, any fault in it can make it inoperative, and you are reduced to checking continuity on individual wires. A bad choice, at least in hindsight, by the car manufacturers. Slow and unreliable by nature!

C112 & C113 views are below. HS-CAN bus is 11 & 12 on C112, and 17 & 18 on C113. Testing individual wires is slow and painful work, I know, I have done too much of it! With luck moving the connectors will make a difference and show the fault location.

For the PCM connector, see:

[broken ford]

Thank you Isetta and Peter,

I will go over the individual wires tomorrow and check the connectors c112, 113, I had left off the trim panel last time.

When I wrote a reading was 0  I meant zero . All the wiring and connectors look like new but something is broken somewhere, hopefully with the good advice from you kind folks it may be found soon.

[broken ford]

so far today I located connectors c112 and 113, all look good, dissconnected and reconnected both. When disconnected I done a continuity test to the correct wires that come from the obd pair (grey blue/grey red) continuity was good for both wires from obd to c112/113.

I don't have any long wires here to bypass existing wires, is there anything else I should look at?

Not sure where to find the wires for the power steering etc, will scrabble around. As I mentioned before, the glow plug light no longer comes on with the ign but the engine warning light does, that is new.

I don't think this problem is going to be solved 😞 6 days all spare time on it so far

 

[broken ford]

found some LAN cable to use, identified the same blue red/grey red wires (this is correct colour combo not as i mentioned before) at the PCM, tested but got 0 zero no 120 ohm

[broken ford]

Found and tested same wires from fuse box connector down to PCM, got contunuity and also tested successful for 120 ohm. So it seems good continuity everywhere but getting 120 everywhere I can check, still 120 at obd. If I could get the obd connector to work I think I could clear faults but not possible so far.

[broken ford]

Have to give up now. Will try putting the car on Gumtree for someone who wants a dementing project, if no interest then off to the crusher.

I hate this car, low mileage but screwed up due to some unfathomable electric issue, I don't want to go through all the rewiring Isetta carried out, I will get more pleasure from taking a sledge hammer to it. at least I learned never to buy a relatively modern ford again, such a waste. Thanks to everyone

a

[isetta]

in case you did not see my thread on my brother's focus it is here

sorry in my post 21 hours ago I got the canbus wire colours wrong didn't I.

I did give up on my brother's car at one point but after a couple of days thinking about it all the time I thought I am not going to let it beat me so that's when I rewired the canbus. 

"at least I learned never to buy a relatively modern ford again, such a waste"  I know what you mean.

There must be loads of cars going to the scrap yard these days because of annoying electrical problems 

[broken ford]

Thanks Isetta,

I read your post this afternoon, after seeing what you went through with all the wiring and still not reliable, I think I am best to give up.

It means I lose £1000 or whatever it is worth...painful. I have never had to scrap a car for a repair problem, still can't belive how poor this design is.

Need to find my sledgehammer now

 

 

[broken ford]

Had another go on sunday, removed the battery to check the ABS connector, all good, like new inside, I could see the twisted wire pair, checking on the plug gave me 120 ohms so I put all back. Next opened the engine bay fuse box at the catches and able to see underneath all the connections, all looked good, no corrosion, no sign of any breaks in the twisted wire pair anywhere. put all back together and still getting 120 ohm at the obd connector which still can't communicate with the ELM reader.

I found and checked the connector high up in the LH footwell, that was good, no corrosion same with the lower two. Looked for more connectors towards the rear but found none, all wiring dry and in good condition.

I have not yet checked the ABS connector, I think Peter said the twisted pair go there, can anyone tell me where to find that connector please, it is the very last one I can check, all others look good still cant understand this.

Regards

 

[Tdci-Peter]

1 hour ago, broken ford said:

I have not yet checked the ABS connector, I think Peter said the twisted pair go there, can anyone tell me where to find that connector please,

The ABS is a pig to get to, up under the bulkhead below the battery. I have only partially seen mine, with all the brake pipes going to it.

The ABS is a spur off the bus, the main bus you are trying to follow does not pass through the ABS connector from plug to socket, I expect two wires to be crimped into the loom connector for each bus line. So just unplugging it and reconnecting it will not alter your fault.

Checking the continuity of the individual bus lines at the more accessible points (C90, C113, C112, OBD and IC) would be an easier way to narrow down the locataion of a break without having to access the ABS from under the car, or the EHPAS (steering) from under the headlight. The engine bay wiring is thicker, and better protected. I think faults inside the cabin area are more likely here, and certainly a bit easier to trace.

The ABS will look something like this:

[isetta]

broken ford, I'm confused. The first paragraph of your message says you have checked abs connector but the last paragraph says you can't find the abs.

this bit below assumes you have reconnected the ECU and everything else:

Now unplug the big plug in the engine bay fusebox.  find the terminals in the plug for the canbus wires, I can't recall exactly where they are but I know they are towards the engine end of the plug, not the end nearest the wing. measure ohms across those two terminals. 

Also whilst the plug is disconnected measure the ohms across two correspending canbus terminals in the socket in the engine bay fuse box. 

Both readings should be 120ohms.

Apologies if you have already done this, the thread is getting so long it's hard to keep in mind everything that's been covered so far.