Auto Handbrake fault

[RichardW]

No that's the yaw sensor for the ESP. ESP functions are integrated into ABS ECU. You really need a wiring diagram, since the handbrake ECU is reporting low voltage - is there a power feed missing? I'll see if I can find one later.

[Aland97]

And the abs ecu is the part by the front wheel correct?? Can’t see anything missing from what I’ve seen and the live data (to me) says that it’s getting correct voltage so I’m literally at a loss

[Aland97]

That’s brilliant I’ll have a look and a read but them wiring diagrams go right over my head sadly… I am well and truly out of my comfort zone here

[RichardW]

What happens if you try and clear the fault? That may not be possible with a generic scanner, you might need Diagbox. Can you do activation tests? What happens if you try and release the handbrake from the scan tool?

Looking at the diagram, there is only 1 power feed, pin 5 at the H/B module, which is ignition switched via Fuse 11 on the BSI. Wire should be numbered BF03. There's only 1 earth, pin 1, labelled MC60G.

Does the handbrake switch light up?

[Aland97]

The handbrake switch itself is lit up, I can hear that the switch operates as it should… I’m using a Topdon artdiag500, when I clear the code it comes back instantly as it says it’s a permanent fault… on my previous posts I put pics up of the live data images not sure if you saw it or not… have a look an see if there’s anything that doesn’t make sense as to me it means sod all lol

[RichardW]

Sorry, that's wrong, power feed is continuous from maxifuse 3. Handbrake appears to be awake as you can interrogate it.

Not sure about the live data, never had cause to look at it. Strikes me that it is saying force is 990kN, but requested is zero, i.e. it thinks it should be off, but it isn't.

P0562 is a bit confusing though, it's an ECM code, so what is it doing in the handbrake module? I wonder if your scantool is leading you astray....

Presume it will start and run?

[Aland97]

Yep car starts and ticks over perfectly, the handbrake fault sign used to come and go very briefly but it’s never got stuck on before? Could it be mechanical and be the actual brakes at the rear seized on perhaps?? I’m wanting to say no because I took it round the block and it was fine then on the same day it wouldn’t release?

[GiveMeABreak]

P0562 is a bit confusing though, it's an ECM code, so what is it doing in the handbrake module? I wonder if your scantool is leading you astray....

Presume it will start and run?

It's not Richard - the fault code is from the ESP / ABS module as this is the controlling ECU in the Master / Slave relationship, so is doing the reporting.

[GiveMeABreak]

This is the specific ABS Circuit for this specific vehicle (I've deleted that previous link to the wiring diagram Richard as it's for a C4 not a C4 Picasso) and completely different to avoid confusion.

[Aland97]

Thanks a lot for that but just for the record, after looking at that diagram I am now sat curled up rocking in the corner crying

But on a serious note, and forgive me if this is stupid as I’m just clutching at straws… the code points to ecu supply under voltage but the live data says 14,4v so could that possibly mean it is in fact the actual motor itself???

[RichardW]

Original thread referred to a C4 Picasso, and the pin out for the data wires shown is the same... That's not the full picture as there is no power supply?

[GiveMeABreak]

The power supply is made to the ESP ECU module (7800) from the Engine Fuse Box (PSF1) on pins [1] BF03U and pin [25] BF04U of the ESP ECU. The module marked 7804 is the ESP Accelerometer, even though it says ESP.

[GiveMeABreak]

7095 is the Electronic Handbrake and CAN control wires are shown from the ESP ECU and the BSI.

[Aland97]

Guys this is by far going straight over my head I’d rather do the head gasket and water pump and cambelt again lol

Apart from set fire to it, what do you think I should be looking at next?

[GiveMeABreak]

Part 2... This is the diagram for the Electronic Parking Brake Specifically. So now you have them both: