C4 Grand Picasso

[nezocas]

Hello,

This was asked many times here, but I am missing wiring diagram for my car.

The problem is, ABS and ESP faults and also no automatic parking brake working.
I have U1208 error with Lexia.
My VIN is: VF7**************[VIN obfuscated, can be read by forum staff]

I have allready stripped the wire harness bewind the baterry but dindt found any broken wire.

[GiveMeABreak]

Fault Code:	U1208
Description of Fault:	No communication with the engine management ECU fault: Data invalid Description of the diagnostics Possibility 1 - The time for recording the fault code is 500 milliseconds - The clutch pedal sensor values sent by the engine management ECU are not coherent with those of the ESP ECU Possibility 2 - The time for recording the fault code is 500 milliseconds - The datastreams from the engine management ECU are not valid Possibility 3 - The time for recording the fault code is 500 milliseconds - The accelerator pedal sensor values sent by the engine management ECU are not valid Conditions of activation of the diagnostics: Ignition switched on
Conditions for Fault to clear:	Possibility 1 - Clutch pedal sensor values sent by the engine ECU coherent with those of the ESP ECU Possibility 2 - The datastreams from the engine management ECU are valid Possibility 3 - The accelerator pedal sensor values sent by the engine management ECU are valid
Downgrade Modes whilst Fault is active:	Possibility 1 - The anti-lock braking system (ABS) function switches to down-grade mode - Immediate cutting of all the speed control functions (Electronic stability control (ESP)) Possibility 2 - The anti-lock braking system (ABS) function switches to down-grade mode - Immediate cutting of all the speed control functions (Electronic stability control (ESP)) - Hill start assistance function inactive - Switching of the electric parking brake to manual mode Possibility 3 - The regulation functions remain active - 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 - Possibility 2 - Warning lamp ESP/ASR Possibility 3 - Warning lamp ESP/ASR - Electric parking brake automatic functions deactivation warning lamp - "SERVICE" warning lamp
Symptoms:	Lighting of the ABS and ESP warning lamps
Suspect Areas:	Connectors CAN network ESP ECU

[RichardW]

Check in the engine ECU for any faults first. As soon as the ECU gets upset it interrupts the data to the ABS ECU, and all the lights come on - but not always the engine management light!! Chased a similar fault on ours for ages, eventually turned out to be the EGR valve at fault.

[nezocas]

Check in the engine ECU for any faults first. As soon as the ECU gets upset it interrupts the data to the ABS ECU, and all the lights come on - but not always the engine management light!! Chased a similar fault on ours for ages, eventually turned out to be the EGR valve at fault.

Hello,

Very good tip.... Yes I have also faults on the EGR valve.
I will clean it in the ultrasonic bath and I will return with the results.

Best regards
Nezocas

[RichardW]

That will probably be it then! If you check in live data it should closely track the requested position - if it doesn't it's sticky.

[nezocas]

Hello,
Cleanning didnt work.
Before cleanning I had P0490 / P1459 / P0409

After cleannin all dtc´s remainned the same.

Waitting new EGR valve.

Regards

[nezocas]

Hello,

Just a late update on this.
After the death of 2 close family members in a short period of time, and my mechanic had time to make room for my car in is shop, the results are:

Egr changed and adapted to car with lexia and no more errors of the Hand brake ABS and ESP.
Since it was in the garage I also changed the Hidraulics fluid of the EGS actuator reservoir (1 litter was more than enougth).
Also changed the gear box oil 1.8 litters of 75W80.

Thanks to all that helped.
Best regards
Nezocas

[GiveMeABreak]

When you changed the actuator oil, I hope your mechanic depressurised the hydraulic system first! The oil level must only be checked against the reservoir guide and topped up if necessary when it has been deactivated using Lexia / Diagbox, otherwise you will over-fill the system and when re-pressurised you will likely end up with problems down the line.

[nezocas]

Hello,

The hidraulics fluid was replaced just by removing the reservoir, doing so the fluid went out.
After he reapplied the tank to its place and top it out to the max position.
Car was started and I shifted gears several times and He was loking to the fluid level, that was going down as I shifted.
As soon as the level dindt go down any more, the tank was toped up.

Not sure if it is the correct way to do.... I am no mechanic.

Regards

[GiveMeABreak]

No, it's not the correct way. As said, the fluid level must be checked and filled to the correct level with the hydraulic actuator circuit depressurised. Then the system must be pressurised and the procedure undertaken to bleed the circuit.

[nezocas]

No, it's not the correct way. As said, the fluid level must be checked and filled to the correct level with the hydraulic actuator circuit depressurised. Then the system must be pressurised and the procedure undertaken to bleed the circuit.

Thank you so much for the advice.

I have noticed, since they changed the fluid, If I maintain a steady accelarator pedal to drive normally and as soon as the 3º gear is engaged, the car seems to lose power for a microsecond, but after that all normal.

Since I have Lexia I could do the oil level check, by Depressurisation of the hydraulic circuit, and after that checking the fluid level. After that I could adjust it.
After that I will Pressurise the circuit.... and bleed.

Can this be done with the reservoir cap ON or OFF?
To bleed the circuit, is this done only with diag tool, or we need to dissassemble something fisically in the car?

Regards

[GiveMeABreak]

The procedure should be guided within Lexia / Diagbox.

Depressurizing the system

• Connect the diagnostic equipment to the vehicle’s diagnostic socket.
• Switch on the ignition.
• Using the diagnostic tool : Select : Depressurisation of the hydraulic circuit.
• All the oil contained in the electrohydraulic actuator unit and in the pressure accumulator returns to the piloting actuator hydraulic reservoir.
• The piloting actuator hydraulic circuit is no longer pressurised.

Repressurising

• Connect the diagnostic equipment to the vehicle’s diagnostic socket.
• Switch on the ignition.
• Using the diagnostic equipment: Select: Pressurising the hydraulic circuit.
• The electric motor of the electrohydraulic actuator unit operates for a few seconds.
• The piloting actuator hydraulic circuit is pressurised.

Bleeding the hydraulic circuit

• Connect the diagnostic equipment to the vehicle’s diagnostic socket.
• Switch on the ignition.
• Select: In the diagnostic tool menu:
  The vehicle
  The RPO no.
  Perform the global test.
• Using the diagnostic equipment : Select : Bleeding the hydraulic circuit.
• The diagnostic tool pressurises the piloting actuator hydraulic circuit, changing through all the gears in order to force air out of the circuit.

[nezocas]

Understood.

Can I leave the cap in the reservoir or remove it in case of excessess fluid added?

[GiveMeABreak]

I can't advise on this as all operations regarding checking / draining / refilling / topping up the hydraulic reservoir involve depressurising the hydraulic circuit first....

I would like to think that the reservoir is only slightly pressurised as it is the hydraulic accumulator that pressurises the circuit for the gearbox and clutch actuators, but I can't be 100% sure. But if you think it has been over filled, you will know soon enough when you depressurise the system again!