broken ford

focus mk2 error code 16 help!

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Hi Peter/ Isetta,

I confused myself, it is the power steering connector I am looking for.

Yes I have reconnected everything though the IC is connected I am leaving it perched on the steering wheel in case I need to strip it yet again.

I already found the ABS connector. I did the check you mentioned and got a reading of 120 ohms but not sure if that can point to a fault location.

Funny thing is that I had 60 ohms at the obd when I first began fault finding, it was after re soldering the IC that I noticed I was getting 120 ohms.

I really appreciate the time and advice to help me sort this

 

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1 hour ago, broken ford said:

it is the power steering connector I am looking for.

Underneath the right hand (driver's side in UK) headlight.

1 hour ago, broken ford said:

I did the check you mentioned and got a reading of 120 ohms

Isetta suggested doing the C90 test both ways, both from the plug and from the socket of C90 itself. One way tests continuity to the ECU, the other way tests continuity back to the IC.

I have had trouble with the original picture of C90 I posted, going all black when zoomed in. I have redone it below. Pins 1 & 15 should be the bus.

C90-1.PNG

If the reading is still 120 both ways from C90 (unplugged), and yet stays 120 when C90 is plugged back in, then the conclusion I have to come to is that the wiring has been previously modified to by-pass C90, and possibly some of the other connectors (C112, C113). So removing C90 has no effect, but still one end of the bus does not have its terminating resistor.

The next test is to disconnect the PCM again, I believe you have already managed to gain access. The bus is on pins A3 & A4 of the smaller of the three connectors:

C418-1-8.PNG

Again test both ways at the pins of the ECU, into the ECU and back into the loom. If the resistance direct into the ECU at its own pins (A3, A4) is high, then I am at a loss to know how to fix this. I do not know whether it is possible to get access to the ECU pcbs. I have left mine well alone, on the "if its not broke, don't fiddle with it" principle! Some places do claim to be able to repair them, but I have heard mixed reports.

One thing I have thought of, measure across these pins with the DMM on voltage range. If the ECU is staying powered up for any reason despite the ign being off, it will put a voltage out on the bus lines, and this will corrupt all resistance measurements. You can only measure resistances with a DMM on circuits that are completely dead (no power in them). If there is any voltage present (more then 1 or 2 milli volts), then unplug all ECU connectors, leave it a few minutes, and try again.

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Hi,  

Just measured the ohms across two correspending canbus terminals in the C90 socket in the engine bay fuse box but had no reading, the connector plug gives 120 ohms but nothing when measuring resistance on the fuse board pins. Does that mean the fault is between the engine bay fuse box connector C90 and the PCM? or to the IC? I had assembled all the PCM unit again but I am happy to do again if needed.

Checked resistance from the OBD and still get 120 ohms no matter if the C90 is plugged in or not.

I checked the other two (MS?) pins on the OBD and got 60 ohms, not sure if that is helpful

When the PCM was out before I did a continuity check from the lowest footwell connector to the PCM and it was fine. It does not look like anyone has added any extra wires in any place I can see, it all seems fairly untouched but there is a connection problem somewhere for sure

I don't think anyone has had problems like this but at least this thread will help them trace faults

 

 

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1 hour ago, broken ford said:

the connector plug gives 120 ohms but nothing when measuring resistance on the fuse board pins. Does that mean the fault is between the engine bay fuse box connector C90 and the PCM? or to the IC? I had assembled all the PCM unit again but I am happy to do again if needed.

Checked resistance from the OBD and still get 120 ohms no matter if the C90 is plugged in or not.

I checked the other two (MS?) pins on the OBD and got 60 ohms, not sure if that is helpful

The added wiring suggestion I made above was based on reading 120ohms both ways from C90. Since you have read high resistance one way and 120 the other, it does not really apply.

Some way above, when the IC was unplugged, you got high resistance (no reading) at the OBD. I would just try unplugging the IC again, as it is easy, and rechecking at C90 both ways again. I would expect it to read high (no reading) both ways then.

If that is true, then we have, unfortunately, narrowed it down to the PCM. Check at the PCM connector itself just to confirm.

The PCM is the last unit I always suspect, they are usually robust & reliable, at least when compared to the rest of Ford's wiring, connectors, and the IC.

The 60ohms on the MS bus is a good sanity check, when jobs go like this, I do begin to wonder if I have gone mad, or just the rest of the world! One sensible reading does help in that respect, at least.

 

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checked the car this morning before work.

Disconnected the IC:   disconnected C90 read 120 ohms from the lead end of the connector block, read 0 at the pins on the fuse board socket.

OBD read at 0 HS pins, and 120 ohms at MS pins

Reconnected the IC:    disconnected C90 read 120 ohms from the lead end of the connector block, read 0 at the pins on the fuse board socket

OBD read 120 ohm at HS pins, I forgot to check the MS pins but I expect they will be 60 as usual, will confirm after work.

Does that mean the PCM is faulty? if so is it possible to replace it with a used unit and reconfigure it?

Thank you once again, if this fault can be sorted then no one else should need to look any further than the good advice I have received here

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1 hour ago, broken ford said:

Disconnected the IC:   disconnected C90 read 120 ohms from the lead end of the connector block, read 0 at the pins on the fuse board socket.

OBD read at 0 HS pins, and 120 ohms at MS pins

Reconnected the IC:    disconnected C90 read 120 ohms from the lead end of the connector block, read 0 at the pins on the fuse board socket

That sounds like very good news. I was expecting an open circuit reading both ways from C90 with the IC disconnected.

In fact, open circuit at the OBD combined with 120 at C90 virtually proves that the PCM is not causing this fault. The 120 at C90 has to be due to the PCM if the IC is disconnected.

If unplugging the IC makes no change in the readings at C90, then the break must be somewhere between the IC & C90.

I would unplug C113 (the higher connector, nearest the bulkhead grommet) next, and make measurements both ways from C113, with C90 plugged and unplugged, and also (separately) with the IC plugged and unplugged.

HS-CAN bus is 17 & 18 on C113. The smaller, inner part of C113 goes to the engine bay, if I am interpreting the picture correctly.

C113.PNG

A problem I have with C90 is I can not tell either from the diagrams or from looking at my car which end goes to the PCM, and which goes to the rest of the car. There are cable looms running from both the fuse box and the cable side of C90 towards the PCM, and the actual wires are all hidden inside. As my engine is working quite well at the moment (!), and disconnecting C90 could power down the PCM and reset the KAM (learnt memory), it is not something I particularly want to do just now. But your tests suggest that the lead end of C90 goes to the PCM, which is what I would expect.

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Thanks Peter,

You give me hope ! 🙂

I think the C90 does go down to the PCM as I followed that large cable bunch when I had the air filter and PCM out.

I will make the checks you suggest as soon as I get home, if I had to make new twisted pairs going from the OBD - IC - C113  that would be reasonably easy.

Kind regards,

Alex

 

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Just checked again.

C113 opened, C90 and IC connected

c113 to bulkhead connector = 120

c113 to footwell connector =120

C90 DISCONNECTED IC CONNECTED

c113 to bulkhead connector = 0

c113 to footwell connector = 120

C90 CONNECTED   IC DISCONNECTED  

c113 to bulkhead connector = 120

c113 to footwell connector = 0

I noticed there is another pair of grey/red and blue/red wires going into 8 and 9 of the C113 connector going to the footwell, they are part of the stock wiring bundle but there are no corresponding pins in the other half of the connector.

I will now go check the other two lower footwell connectors

 

 

 

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Lower (smaller) connector in passenger footwell.

IC + C90 connected

plug end to bulkhead direction =120 ohm

plug end to floor direction - 0

IC connnected, C90 disconnected

to bulkhead = 120 ohm

to floor = 0

IC disconnected, C90 connected

to bulkhead = 0

to floor =0

I then used some lan cable twisted pair wires to connect between C90 and the IC but it made no difference, I still got 120 ohm at the OBD.

The connection was temp and not the best, used paper clips into the c90 end and made a nick in each of the twisted pair just before the IC but I think I made the connection ok. Not sure doing that was useful or not

 

 

 

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3 hours ago, broken ford said:

C113 opened, C90 and IC connected

c113 to bulkhead connector = 120

c113 to footwell connector =120

That is a bit unexpected. Clearly, from those results there is a good path from one side of C113 to C90 and on to the PCM. And there is also a good path from the other side of C113 to the IC. Confirmed by changes to high reading on disconnecting either C90 or the IC.

Either the gremlin is moving about, trying to escape detection (!), or the problem is that one of those contacts in C113 is not actually making contact when plugged together.

1 hour ago, broken ford said:

Lower (smaller) connector in passenger footwell.

IC + C90 connected

plug end to bulkhead direction =120 ohm

plug end to floor direction - 0

The floor direction from C112 is towards C113, C90 & the PCM. And seems to still be broken, which stacks up with the fault being in C113.

The bulkhead direction from C112 is actually towards the OBD and the IC. And that direction is ok, as expected.

It is worth re-testing the C113 again, to make sure the gremlin is still there. And have a really close look at the pins. Just one a bit bent out of shape, or a trace of tough dirt could cause the open circuit. If the measurements stay consistent as you have reported them, then I would use scotchloks to connect a very short bit of twisted wire from one side of C113 to the other side. Or just cut the two wires each side and solder them. The only use for C113 normally is when assembling the car, harnesses can be installed while building up sections, then plugged in when the sections are joined up. Once built, it must be very rare to need to disconnect, except for diagnosis tests like here.

 

Pins 8 & 9 on C113 are for a separate circuit between the ABS and the Yaw rate sensor, part of the ESP system. On the diagram it says fitted from Oct 2008, so it may not be there on a 2006 car, explaining the pins on one harness but not on the other. This is the circuit that is still causing trouble for Isetta's brother. But I don't think it has anything to do with the main HS-CAN bus.

 

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Respect for you and your knowledge, really appreciate the experience and time you are giving

I will thoroughly check C113 tomorrow, it is in such a difficult location but well worth checking all again, feeling confident now 🙂

If I cant see anything I will solder new wires across as you suggest. Lets hope for good news tomorrow !

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IT IS FIXED!!

Looks like it was the lower connecor in the passenger footwell (c112 I think) for the first time I managed to get a couple of wires from the OBD to a multimeter so I could see the ohm output as I was playing with connectors c113 and c112. I was about the make a wire bypass for C113 and went for one last wiggle check where I could see the result on the DVM, nothing on c113 so reconnected, it was C112 was nearly at closed that my seem it went to 60 ohms from 120, I tried closing the connector...120 ohms, went back to nearly closed...60 ohms. Tried that a few times, it was quite sensitive. Quickly got the laptop and obd reader and (eventually worked out how to )cleared the fault codes, the car then started !

Kept the engine running and closed c112. it kept running, no warnings, moved it around a it and still running, no errors.

For a connector that would only give 60 ohms if very carefully positioned it seemed fine and robust after the car was running and the faults cleared.

I have left it like this, run the car around, stopped and started a few times...what the heck happened?

I am happy but dont get what is going on with a very sensitive connector that can now be closed and moved without disruption. Not sure if I should make some new bypass connectors for this connector or just leave it.

Anyway, it runs 🙂 I would like to thank Peter and Isetta sincerely for the good help and saving my car

 

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