C5 X7 ESP/ABS fault with codes and pictures

[admiral51]

Hi All
My C5 X7 after having the starter motor replaced has now thrown up ESP/ABS warning lights. I have not yet driven it to see it happen but it popped up on Tuesday morning once and nothing showing up again until Friday morning.
Popped out with the Lexia and nothing showing on the dash when engine started and stationary but do have faults stored. Cleared all faults and another global scan came back clean.

Seems to me that it all down to the 2 Brake sensors but which one.
Hopefully not too expensive

Colin

[admiral51]

Right i have done a bit of the old google search and it seems that the Brake Pedal Switch could be the problem, someone else had the same fault code C0040. As it is a cheap part to replace and i hope easy to get at then i think i will go down that route.
Guess the switch is actually located on the passenger side of the vehicle if Citroen are true to form ?

Colin

[GiveMeABreak]

Ok, so this is a long one Colin.

1) Fault Codes
2) Part for harness / Switch
3) The TSB for a known issue concerning malfunctioning of the stop lamps and / or lighting of the ABS / ESP Warning Lamp


So here are both those faults and they are obviously related:

1) Faults:

Fault Code:	P1536
Description of Fault:	Brake pedal sensor: Incoherence between the 2 brake sensors detected when decelerating. Incoherence between the main brake and the secondary brake during a gross deceleration for 1 second. Engine running.
Conditions for Fault to clear:	Driving with engine hot for 5 minutes with numerous brakings
Downgrade Modes whilst Fault is active:	Deactivation of the injector resetting strategies Irreversible deactivation of the vehicle cruise control (Need to switch the ignition off and then on, in order to make the function available again) Deactivation of the after-sales test for detection of leaks on the diesel fuel high pressure circuit
Symptoms:	Lack of power
Suspect Areas:	Brake pedal Brake switch Electrical harness Connectors

Fault Code:	C0040
Description of Fault:	Brake pedal switch fault: Coherence with the pressure sensor. Ignition switched on. The time of appearance of the fault code is 1s Incoherence between the calculated pressure and the movement of the brake pedal Incoherence between the pressure at the master-cylinder (higher than 80 bar) and the movement of the brake pedal (zero) Warning Lights: Service ESP/traction control ABS
Conditions for Fault to clear:	Coherence between the calculated pressure and the movement of the brake pedal. Coherence between the pressure at the master-cylinder and the movement of the brake pedal.
Downgrade Modes whilst Fault is active:	The ABS operation that is current goes its term. Once it is finished, cutting of all ABS operations Immediate cutting of all the speed control functions (ESP) The electronic brakeforce distribution function is in down-grade mode Deactivation of the hill start assistance
Symptoms:	Lighting of the ABS and ESP warning lamps.
Suspect Areas:	Pressure sensor (Internal to the ECU ESP) Fuses Electrical harnesses Connectors

2) Parts
Be aware that there are 2 possible types of brake switch (manual adjustment and automatic adjustment).

This is the part:

Item (10) Strap Switch Kit, part: 453467, £55.13

3) TSB Details

Fault Origin:
Brake Switch (on braking)

Repair:

• Install an intermediate electrical harness.
• Replacement of the brake lamp switch.

Parts Needed:

• 1 Switch kit (See part no. above).
• 1 Plastic clip (Packaging of 50 - Part number 6980A1).
• 1 Foam (Packaging of 20 - Part number 936572).

Disconnect: The electrical harness (1).
Replace: The brake lamp connector (2).

Position: The intermediate electrical harness (1):

• Connect the intermediate electrical harness (1) to the stop lamp switch (2)
• Connect the other end of the intermediate electrical harness (4) to the electrical harness (1)
• Wrap the connector (3) linking the intermediate electrical harness (4) to the electrical harness (1) with the foam (5)
• Attach the 2 electrical harnesses (1), (4) together ; Using a plastic clip (6) (Moderately tighten)
• Cut the excess length from the plastic collar (6)

Check that there is no interference between the electrical harnesses and the pedal gear.

[admiral51]

Hi Marc
Thanks for the info think i am going to have to gain access and get some pictures of what is currently on the car.
I have spoken to the good lady and when it came up on Friday she was overtaking a car on a dual carriageway and not breaking so my head ( and wallet ) is leaning towards the Brake Switch when looking at C0040 when it states Zero movement of the brake pedal.
Would you be ok if i take some pictures of the part on the car and advise me if it is the manual or automatic version of the switch?
I guess that the price for the Strap switch kit includes everything i would need and can be ordered from my local stealers

Thanks again Marc really appreciate what you and the other Leaders do.

Colin

[GiveMeABreak]

I can't say if the clips are included or not Colin, they would have to advise you of that at parts.

As for the switch removing and fitting, I included the procedure a while ago in another thread here with pics:

viewtopic.php?p=604210#p604210

[admiral51]

Thanks Marc why every Citroen owner is not a member here escapes me

Colin

[admiral51]

Marc one last question, is it obvious to distinguish between the types of switches you know what i am like

Colin

[GiveMeABreak]

I couldn't tell you Colin, the first image in the links would just appear to show the module rotated. However the refitting part for each type is different and key to setting it correctly. So maybe you can determine this from the one you get - or get the dealer to fit it for you if unsure.

[Doo]

Hi All
My C5 X7 after having the starter motor replaced has now thrown up ESP/ABS warning lights. I have not yet driven it to see it happen but it popped up on Tuesday morning once and nothing showing up again until Friday morning.
Popped out with the Lexia and nothing showing on the dash when engine started and stationary but do have faults stored. Cleared all faults and another global scan came back clean.






Seems to me that it all down to the 2 Brake sensors but which one.
Hopefully not too expensive

Colin

I had to replace the brake switch on a C4 manual a few years back. Simple affair, if not the most comfortable due to the positions you have to assume to get to it

It was simple to adjust as it's a click click affair. Get someone to press the brake pedal, insert the switch and get them to let the pedal off slowly and the switch should adjust itself (unless the procedure has changed/is different on the C5). Plug in, switch on & test. Can't recall if you have to delete the codes, but most probably...

[admiral51]

Ok just a quick update.
Cleared all the codes yesterday and finally got chance to take it out to see if i could get it to throw up the fault.
I have only managed to get it to throw up the fault once and having done another scan it is the same 2 codes C0040 and P1536.
It only came on when i was doing maybe 5 mph and stamped on the brakes hard. Switch engine off and on again and fault has gone. I have tried standing on the brakes from various speeds up to 40 mph and the car just behaves itself.
So going to take it to work and back tomorrow and see how it behaves.
Yes i will be getting it replaced i just want to see how intermittent the problem is and knowing the car will have no ABS/ESP when the fault is active i at least know what to expect, it has brakes just no ABS.

@Doo It is a little bit different on the C5 X7 there are a couple of switches, one is plug and play the other needs manual setting knowledge gained from the ever reliable Marc.
Fingers crossed the one i have is the plug and play variety

Colin

[admiral51]

Well yesterday no issues at all, she behaved herself 100%
Today she acted like a teenager who had just been told no internet and no phone for the next 24 hrs. Touch the brakes and and it shouts it has a problem.
Calling my local stealers tomorrow with the info kindly provided by Marc and guess i am looking at a small stint of doing the twister in the passenger footwell

Colin

[admiral51]

Well called them and got nowhere with the kid fresh out of nursery so decided to go a see them today.
It is on back order, could be anywhere between 2 weeks and 2 months and they want £57.89.
I have looked online and found This one .
Think it is the right part and only £37.38 + delivery so if anyone can confirm it is correct i will order it today

Colin

[RichardW]

Looks like the right one

[KennyW]

Colin,
The guys at eurocarcare are good and will confirm if it is correct.
Kenny

[admiral51]

Thanks Kenny/Richard
I have ordered one and going by the info on the website it does look to be the right part.
I forgot but i have used them in the past for a replacement engine fuse box on my old C4 2005 and i totally agree with you Kenny a proper site that knows their stuff.

Colin