PDC an ongoing saga

billh · 3rd February 2021, 21:08

The parking sensors have not worked for some time now- a 5 second beep when reverse is engaged, telling me they aren't working. TOAF tells me all sensors are open circuit. I repaired dodgy wiring inside the rear bumper and checked continuity between the ecu and each sensor plug- all ok. I measured the supply voltage at each (sensor disconnected) sensor plug with reverse engaged and ignition on, all four were about 5.5 volts- I expected to see 12v but what should it be? I am thinking the ECU ( a black one) has gone faulty, what do others think? Thanks in advance for any ideas.
Forgot to add: There is no click from any sensor

SD1too · 4th February 2021, 08:36

Hello Rob,

I've looked but RAVE doesn't give the power supply to the sensors (brown wires). It's unwise to expect it to be 12v since we know that the ECM uses a 5v supply to sensors.

I'd expose the PDC ECU and check for water damage. If there is none, I doubt that it has failed. It's more likely to be a problem in the inhospitable area behind the bumper. Do the sensor 3 pin connectors live there or are they inside the boot?

If it wasn't for the travel restrictions you could take it to Jules for a T4 session. RAVE says that any fault codes will be stored in the PDC ECU.

Simon

MacRob · 4th February 2021, 08:53

Quote:

Originally Posted by billh

The parking sensors have not worked for some time now- a 5 second beep when reverse is engaged, telling me they aren't working. TOAF tells me all sensors are open circuit. I repaired dodgy wiring inside the rear bumper and checked continuity between the ecu and each sensor plug- all ok. I measured the supply voltage at each (sensor disconnected) sensor plug with reverse engaged and ignition on, all four were about 5.5 volts- I expected to see 12v but what should it be? I am thinking the ECU ( a black one) has gone faulty, what do others think? Thanks in advance for any ideas.
Forgot to add: There is no click from any sensor

Hope this helps you solve things

3rd February 2021, 21:08	#1
billh Regular poster Rover 75 Tourer Join Date: May 2007 Location: Denton, Manchester Posts: 79 Thanks: 14 Thanked 24 Times in 14 Posts	PDC an ongoing saga The parking sensors have not worked for some time now- a 5 second beep when reverse is engaged, telling me they aren't working. TOAF tells me all sensors are open circuit. I repaired dodgy wiring inside the rear bumper and checked continuity between the ecu and each sensor plug- all ok. I measured the supply voltage at each (sensor disconnected) sensor plug with reverse engaged and ignition on, all four were about 5.5 volts- I expected to see 12v but what should it be? I am thinking the ECU ( a black one) has gone faulty, what do others think? Thanks in advance for any ideas. Forgot to add: There is no click from any sensor Last edited by billh; 3rd February 2021 at 21:19..

4th February 2021, 08:36	#2
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,380 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Rob, I've looked but RAVE doesn't give the power supply to the sensors (brown wires). It's unwise to expect it to be 12v since we know that the ECM uses a 5v supply to sensors. I'd expose the PDC ECU and check for water damage. If there is none, I doubt that it has failed. It's more likely to be a problem in the inhospitable area behind the bumper. Do the sensor 3 pin connectors live there or are they inside the boot? If it wasn't for the travel restrictions you could take it to Jules for a T4 session. RAVE says that any fault codes will be stored in the PDC ECU. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.