Park Assist Service Sensors

[kozy]

Hi folks - I had the infamous “service park assist sensors” message pop up on the dash. I replaced all four rear sensors and no resolve. I checked the rear harness plug and it is dry. Problems all started after we received snow this winter. Any thoughts on what to tackle next?

 

[Tremper126]

I’d check all your grounds to the frame

 

[autoX]

I have the same issue - all four sensors show a problem in my new AlfaOBD setup!
Sensors have 3 wires:
+8.6Volts power
-ve or Ground from the module
And Signal back to the module

EDIT Module is under driver kickpanel. I'm going to test at the sensors first for +ve

Tested 8.6V at sensor is OK
Ground seemed fine

 

[autoX]

I spent two hours fiddling with the rear circuit.
One new "ebay" sensor plugged in will create 3, sometimes 4 faults. 4 ebay sensors give 4 faults.
One bad Bosch sensor, with 4 Bosch installed, will trigger 1 or 2 faults. So it's hard to isolate but I did manage to narrow it down to one suspect.
Very strange behaviour from the main CPU and not at all consistent.
The Bosch sensors did give the most reliable results however. I have ordered 2x new from NAPA I know those work OK. We'll see if I can get it work this weekend.

 

[autoX]

Solved it. I have the rear circuit working back to normal. 3 of the 4 sensors were bad!
I had to use the FRONT circuit as a test bed, & check/verify the used sensors I pulled off the back bumper

With 2 NEW Bosch sensors from Lordco auto parts ($80 each). One good sensor from front, the Rear is OK.

Front circuit is down a sensor now, but have another two on order.

I was getting "Wipe sensors" errors with 2 of the rear/used. Not a full fault. One I was getting a hard fault.

Really difficult to track. The EBAY sensors threw the whole module into a tizzy and would cascade faults. ie
Confirmed my 4 x EBAY sensors are no good at all.

 

[Tremper126]

Good to hear! Unfortunately our vehicles are becoming smarter, and if it’s not “as good as factory” it won’t like it. I put led lights in my cargo light and continued to get messages for reverse lights out!

 

[Multiplex49]

Clean your back up, camera disconnect, quick disconnect, connectors and add dielectric grease to the connections.

 

[autoX]

I cleaned all connections with LPS electric cleaner. That's all good. I marked the sensors and confirmed faulty or near faulty, swapping them into the left front. Which is easy to do, just turn the wheel, bend back the inner fender and jack up a bit. Clip in one sensor and let the mayhem begin! So it was easy to confirm good/bad.

The sensors that cause the "Wipe sensor" message don't actually throw a code, so they are hard to trace. And even when say one sensor trips a code, it can affect an adjacent channel.

So these youtube videos of guys replacing all 4 rears - not a bad idea at all.