Parking sensor issues.

[privatemeekly]

Hi.

My increasingly cranky 2012 B7 has decided to give me yeat another headache - the Parking sensor system.

Whenever you try and turn it on, you just get a long loud beep & a message that it is unavailable on screen. I've done some looking and had VCDS on it, and get this:

Address 10: Park/Steer Assist (J446)       Labels:| 3AE-919-475.clb
   Part No SW: 3AE 919 475     HW: 7N0 919 475 
   Component: PARKHILFE 8K  H04 0009  
   Revision: --------    Serial number: 77631129707624
   Coding: 118002
   Shop #: WSC 99999 123 12345
   ASAM Dataset: EV_EPHVA18VW47X0000 001003
   ROD: EV_EPHVA18VW47X0000.rod
   VCID: 7CF72BB4F70C176657-8028
2 Faults Found:
1079828 - Supply Voltage for Parking Aid Sensor(s) 
          B107A 14 [008] - Open or Short to Ground
          Intermittent - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 3
                    Fault Frequency: 254
                    Reset counter: 102
                    Mileage: 396201 km
                    Date: 2024.10.05
                    Time: 17:54:47
1079830 - Supply Voltage for Parking Aid Sensor(s) 
          B107A 16 [009] - Voltage Too Low
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 3
                    Fault Frequency: 114
                    Reset counter: 63
                    Mileage: 397565 km
                    Date: 2024.10.05
                    Time: 18:03:44

Car details:

VIN: WVWZZZ3CZCE099048 License Plate:
Mileage: 398250km-247461mi Repair Order:

I've checked all the fuses I can find (although I have no idea which one might be giving the unit power - as the fuse diagram folk keep quoting doesn't seem to match the car!), I've had the control unit out, and checked it - no green death, magic smoke escape or other signs of potential deadness.

I've done the whole 'check for the sensors clicking' thing - and none of them do. My current guess is some sort of wiring loom issue, or the control unit has just decided that it has had enough. Can someone point me in the right direction for diagnostics please?

Thank you.

[Crasher]

The unit provides the voltage, one of the sensors is causing this. You bring up the voltage in measuring blocks and unplug them one at a time waiting for the voltage to come back, I like to torture my techs so I make them start front left knowing the law according to sod dictates it is the rear right. New sensor 1S0 919 275 C GRU (primer) £139.20 all in.

[gareth23]

Could also be the plug or wire in the loom, my car is getting a new front sensor loom on Monday as the parking system stopped working. VCDS said front left sensor faulty but moving sensors around didn't change anything - it always said front left fault.

[privatemeekly]

Thanks Crasher.

Looks like that is this weekend's job then!

[privatemeekly]

Thanks Gareth - I'll swap a sensor round before I buy one to double check.

[privatemeekly]

I should probably have asked what voltage it should be.... I'm seeing 4.7v all plugged in, then 5v with the front left unplugged (what a sod they are to get at when you're making it up as you go along!)

[Crasher]

You should see circa 12v when the faulty one is unplugged.