C4 Picasso, ABS, Electrovalves, Intermittent

[GreyElephant]

Any help please?

My C4 Grand Picasso 1.6 HDi, manual, 2007 - I've had it for nearly 16 years.

A few months ago, it had regular intermittent fault which then 'resolved itself' until last week, now the original intermittent problem has returned. It may be ok for a few miles, then the symptoms occur:

ABS, ASP and ESP warnings, auto-parking brake not working, hill start assist not working.

I have a Topdon scanner which shows up to 5 faults, all intermittent:

U1208 - Fault in communication with the Engine Management ECU or drive train ECU, data invalid.

C1385 - Electrovalves supply voltage fault, not characterised.

C1367 - Switching electrovalve 2 fault, not characterised.

C1346 - Rear RH inlet electrovalve fault, not characterised.

C1341 - Fault on the rear LH inlet electrovalve, not characterised.

I have googled it and wonder if it could be a faulty 'double relay', but no idea if this car has one or where it would be? Or if this could be the cause?

Or could it be issues with fuses or wiring?

I spoke to a Citroen specialist who suggested 99 percent chance it is faulty ABS ECU, in which case potentially terminal.

But, the thing is, it has NOT completely failed, it is intermittent, which means it also works ok at times - Is that positive?

Any experience or ideas out there, please?

I am really hoping for a quick easy remedy, or things to try.

I am an electrical DIYer, not a car tech.

But any help would be very much appreciated!

Many thanks in advance.

[RichardW]

Are there any faults on the engine ECU, particularly with the EGR valve?

[GreyElephant]

Thank you for your quick reply.

I had only recently cleared the ABS fault codes, but checking it today (after a journey when all the ABS warnings and symptoms occurred again), only 2 of the aforementioned ABS codes have returned, C1385 and U1208, both intermittent, so it is not always that all of the aforementioned codes are recorded.

In answer to your question, under engine fault codes I have:

P0409 - Permanent fault, EGR valve. Valve detected jammed shut during the ECU sleep phase.

P0490 - Intermittent, EGR valve. Position incorrect (too closed).

P0401 - Permanent fault, Air circuit. Registering of a fault on the slave node of the alternator LIN network.

Then, under Built-in Systems Interface, there is a fault code 05FF, not characterised, unexpected re-initialisation fault coming from the BSI. Don't know what this is or if is anything to do with it?

Regarding the ECU fault codes, I have noticed that I have had permanent fault codes recorded even when the ABS was temporarily behaving itself over the last few months, so, possibly wrongly, I assumed that the ECU wasn't causing these ABS problems, but who knows?

I hope this added info will help to point in the right direction?

Many Thanks.

[RichardW]

It's likely that it's the P0490 causing it. Can you read live data? If so check what the reported EGR valve position is vs the requested position as you rev the engine up and down - it should be very close. I suspect it will not be. What happens is that the EGR hiccups and this interrupts the engine signal to the ABS resulting in the U1208 which puts all the lights on. You may still have another issue with C1385, but you need to fix the EGR valve first.

[GreyElephant]

I have some more information...

I am a bit new to operating scanners and car diagnostics on post 80's / 90's electronic cars, but I do have a background in electronics/ electrical engineering, so please bear with my ignorance.

I have just been for a drive whilst using varying throttle position, engine rpm and demand on hills, whilst monitoring the live traces.

I am hoping I have used the correct traces as indicated below.

What I found is that the following three roughly track each other:
- EGR throttle opening control
- EGR throttle position opening control
- EGR valve opening control

But the following trace flat-lined, stuck at the bottom of the graph:
- EGR value (I assume that should be valve?) opening control

Am I right to assume that the EGR throttle is not the item in question here, and that it closes the air intake to force recirculation via the EGR valve?

And am I right in thinking that the that the 'opening control' is the demand signal or requested position, and that that the 'position opening control' is the actual position achieved?

If all of that above is correct, then to my novice understanding, I would hazard a guess that the ECU is requesting movement of the EGR valve, but the ECU is getting no feedback from the EGR, so it could be:
- signal not getting to the EGR
- EGR stuck or faulty
- signal being returned by the EGR, but not received by the ECU

Am I on the right tracks? If so, I've got no idea where to go from here! Can it be tested?

If the EGR is just gunged up, is it possible to recover it in situ, such as a cleaner? If so, how?

And how likely is it that all of the above could be the cause of the ABS issues, especially considering that the EGR fault codes have been recorded over recent months whilst the ABS has been temporarily behaving?????

Sorry, loads of leading questions, possibly wide of the mark, but hopefully you can put me right.

Again, I appreciate your help with this.

Many Thanks,

David

[GreyElephant]

Hi Richard,

Did the live data tests which I carried out and mentioned in my previous post give any useful pointers to what is going on?

Thanks, David

[GreyElephant]

I just noticed a critical word missing in my reply above.

I repeat the clause below with the missing word in capitals:

But the following trace flat-lined, stuck at the bottom of the graph:
- EGR value (I assume that should be valve?) POSITION opening control

Therefore, as all of the other traces mentioned are roughly tracking each other, does this mean that the EGR valve is stuck in the closed position, or that there is a fault in the wiring to the EGR valve, or a fault in the wiring from the EGR?

As this EGR fault seems to be permanent, and has been showing for some time, is it possible that this could still be causing a new and intermittent problem returning on the ABS?

Is there a quick fix for the EGR, such as cleaner?

If the EGR is unlikely to be the root cause, what area of the ABS system do I need to be looking at?

Many Thanks, David

[RichardW]

I think the EGR Throttle is the the swap over valve that bypasses the intercooler to get the temp up for regen - so it's normal to see these giving flat / odd looking readings. The EGR valve sitting at 0% isn't.... It could be a broken wire, if you had a wiring diagram it should be possible to short the signal wire to the 5V reference and get a 100% reading. The valve being stuck shut is probably more likely - t's not as hard to remove as it looks, and you can take the head off and clean out the bottom part to see if that fixes the fault. It might or might not be causing the ABS issue, but you need to fix that first and see what happens to the ABS fault.

[GreyElephant]

A quick update and urgent help needed please...

The C4 Grand Picasso has been in and out of a Citroen Specialist since my last post.

They cleaned the EGR valve (and had to update software and calibrate), this cleared the EGR codes and I was assured that it would now be all ok.

Less than 20 miles later, the intermittent ABS faults returned.

Back to the garage to check it out again, they then had it in for a third time to replace the ABS ECU / pump with a secondhand unit off ebay, this had a faulty piston, so they swapped one of the pistons off of the removed unit. They also found that the mounting bracket had rusted away so made a new bracket. Then a bleed nipple was seized, so they replaced a caliper with a secondhand unit.

They still got ABS fault code C3185, then found a cable under the battery with a suspect repair, so they re-made this connection, road tested it and said that it was now all ok.

I went to pick it up yesterday and immediately found that the brake pedal went down way too far and was terribly soft, I mentioned this and was told that it was because the caliper needed to bed in and calibrate - l'm not convinced - Does that make sense, or is there still air in the system? Which I suspect.

If it is air, is it safe to drive it like this to see if it does 'bed in' as they suggest, or is that really dangerous, as it feels really bad to me.

However, I only drove it a few yards in their carpark and all the brake / ABS warnings appeared AGAIN.

So they put the scanner on and got the same code again:
C1385 - Electrovalves supply voltage fault, not characterised.

They said they now had no idea, but said that their ABS man was coming in today so would get him to look at it, but I haven't received any updates so am getting very worried now.

Regarding the fault code C3185, I have looked online and a likely culprit on various Peugeot Citroen cars seems to be a double relay on the front of the fuse box in the supply feed to the ABS ECU, but I have been unable to find it, and the garage have also been unable to find it. There is a single relay there, but I think it is for glow plugs.

Any ideas where this double relay is on the C4 Grand Picasso?

Any ideas of what can cause C3185?

Any ideas what could be going on here in general?

Also any help regarding my queries about the soft brakes and low pedal?

Of course, I really don't know if all the original fault codes have been permanently resolved yet...

Any help or support would be much appreciated.

Many Thanks,

David

[GreyElephant]

CORRECTION - I've just noticed a couple of errors in my previous message...

The error code is:

C1385 - Electrovalves supply voltage fault, not characterised.

Wherever I said C3185, it was meant to say C1385.

Does that help?

I'm desperate for help here please...

Thanks in advance

David

[GiveMeABreak]

Fault Code:	C1385
Description of Fault:	Solenoid valves supply voltage fault: Not characterised. The time for recording the fault code is 50 milliseconds after activation of the solenoid valves relay test. The solenoid valves relay test is carried out after each initialisation of the ESP ECU and then every 20 seconds. Problem on the solenoid valves supply relay supply line (Open circuit, short circuit to positive, short circuit to earth). Conditions of activation of the diagnostics: Ignition switched on. The solenoid valves relay test cannot be carried out if another test is in progress (Solenoid actuator test)
Conditions for Fault to clear:	The relays supply the ESP ECU solenoid valves correctly
Downgrade Modes whilst Fault is active:	All of the regulation functions are inactive Hill start assistance function inactive Switching of the electric parking brake to manual mode Switching on of the warning lamp and/or warning message: Possibility 1 ESP/ASR indicator lamp ABS indicator lamp Electric parking brake automatic functions deactivation warning lamp SERVICE indicator lamp Possibility 2 ESP/ASR indicator lamp ABS indicator lamp Electric parking brake automatic functions deactivation warning lamp SERVICE indicator lamp Warning lamp for handbrake, brake fluid level and brakeforce distribution malfunction STOP warning light
Symptoms:	Lighting of the ABS and ESP warning lamps
Suspect Areas:	Electrical harness Incorrect battery voltage Fuses CONNECTORS

Fault Code:	C1367
Description of Fault:	Switching electrovalve 2 fault: Not characterised. The time for recording the fault code is 3 seconds after the test has been carried out on the electrovalve by the ESP ECU. Short circuit to positive; Short circuit to earth Open circuit Resistance value outside range Conditions of activation of the diagnostics: Vehicle speed higher than 20 km/h Brake pedal not pressed No ESP regulation
Conditions for Fault to clear:	The test on the electrovalve shows that it is supplied correctly by the ESP ECU
Downgrade Modes whilst Fault is active:	Immediate cutting of all the speed control functions Electronic brakeforce distribution function inactive Hill start assistance function inactive Switching of the electric parking brake to manual mode Switching on of the warning lamp and/or warning message ESP/ASR indicator lamp ABS indicator lamp Electric parking brake automatic functions deactivation warning lamp SERVICE indicator lamp Warning lamp for handbrake, brake fluid level and brakeforce distribution malfunction Imperative stop warning lamp
Symptoms:	Lighting of the ABS and ESP warning lamps
Suspect Areas:	Battery voltage Fuses Connectors Electrical harness

Fault Code:	C1346
Description of Fault:	Rear right inlet electrovalve fault: Not characterised. Description of the diagnostics: The time for recording the fault code is 3 seconds after the test has been carried out on the electrovalve by the ESP ECU. Possibility 1 Short circuit to positive ; Short circuit to earth Possibility 2 Open circuit Possibility 3 Resistance value outside range. Conditions of activation of the diagnostics: Vehicle speed higher than 20 km/h Brake pedal not pressed No ESP regulation
Conditions for Fault to clear:	The test on the electrovalve shows that it is supplied correctly by the ESP ECU
Downgrade Modes whilst Fault is active:	Immediate cutting of all the speed control functions Electronic brakeforce distribution function inactive Hill start assistance function inactive Switching of the electric parking brake to manual mode Switching on of the warning lamp and/or warning message ESP/ASR indicator lamp ABS indicator lamp Electric parking brake automatic functions deactivation warning lamp SERVICE indicator lamp: Warning lamp for handbrake, brake fluid level and brakeforce distribution malfunction, STOP warning light
Symptoms:	Lighting of the ABS and ESP warning lamps
Suspect Areas:	Incorrect battery voltage Fuses CONNECTORS Electrical harness

Note the C1341 code is identical to that above, except it relates to the Rear LH Inlet Electrovalve.

[GreyElephant]

Thanks Mark,

Do you know exactly where I can find this relay is on the C4 Grand Picasso?

And what type of relay it is, how is it identified, such as description, part number, etc?

Thanks,

David

[GiveMeABreak]

Let me have your VIN and I'll see if it is shown on the electrical diagrams. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[GreyElephant]

I hope this helps VF7**************[VIN obfuscated, can be read by forum staff]
Thanks
David