1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

W251 R class Parking sensor control module location?

Discussion in 'Electrics, Vacuum, Ignition and ECU' started by The Rev Dr Syn, Mar 22, 2020.

  1. The Rev Dr Syn

    The Rev Dr Syn New Member

    Messages:
    4
    Likes Received:
    2
    Joined:
    Mar 22, 2020
    Your Mercedes:
    2008 R 320 L CDI
    Hi, can anyone tell me where the PCU is located in the R class?

    I picked this car up yesterday and I'm getting two red dots in the front distance indicators and a beep before the system shuts itself off. Turning the system back on has the same result. I have not yet seen any lights/noise from the rear indicators.

    The front sensors did work briefly yesterday but entered a fault state again when we next dropped below 15mph.

    I realise I could do with getting it on a diagnostic machine, but I would like to do some visual checks before I do that incase it is simply a bad connection somewhere.

    TIA for your help :)
     
  2. mioba

    mioba Senior Member

    Messages:
    1,198
    Likes Received:
    239
    Joined:
    Feb 19, 2006
    Location:
    Nottingham
    Your Mercedes:
    W124/1994/E200, W220/2004/S320CDI, W205/2016/C200, W447/2017/3.0 CDI
    Unless you are an electronics circuit guru i doubt you could spot a loose connection on the PCU.

    Best to get on diags as its probably a sensor out / loose connection in the bumper.
     
  3. OP
    The Rev Dr Syn

    The Rev Dr Syn New Member

    Messages:
    4
    Likes Received:
    2
    Joined:
    Mar 22, 2020
    Your Mercedes:
    2008 R 320 L CDI
    I decided to do a visual check as far as I could and I'm glad I did, I managed to find the problem by fluke when chasing the looms through the car and found that the loom was disconnected in the cubby behind the R/H rear lights. I connected it back up and now the system works perfectly. I'm glad I did check as the diagnostics would have probably told me all the rear sensors had failed.

    I can only assume the loom was disconnected by mistake by whoever installed the towbar for the previous owner. I'm just glad it was an easy an inexpensive fix once I found it!
     
    EmilysDad likes this.

Share This Page