Park Assist Service Required

[nick257]

Hi All, 1st post on this forum...

Have an XC90, 2007, low mileage (60k miles). Got the common "Park Assist Service Required" message about 6 months ago. The car has the rear parking sensors only. The dashboard message used to go away after rain, and returns when the car is dry!

So... to tackle the problem... bought the DICE system, installed on Win7. DICE reports "parking sensor 1" faulty.

So far.. I have :

• replaced all 4 rear sensors with new ones.
• replaced the entire parking sensor wiring loom (from the Parking Module, to each of the rear sensors).
• replaced the parking module (ECU)!
• replaced the Fuse in rear fuse panel (in boot)

Have of course reset DTCs (error codes) at each step, via DICE.

What have I missed? Is there a relay, or some other component I have missed? Any help much appreciated!

[SwissXC90]

Your symptoms are a clue. Look at the Firmentitels of pod 1 sensor in the bumper

Be aware of osmosis around the sensor in the housing

[nick257]

all 4 sensors, and the wiring, have been replaced with new parts...

[gmonag]

Did you use genuine parts?

[SwissXC90]

Originally Posted by nick257

all 4 sensors, and the wiring, have been replaced with new parts...

Are the sensors in the housings snug?
There was a service bulletin about water entering the space between sensor and housing thus impacting the ultrasonic signals.

Google for a service bulletin...

[nick257]

Originally Posted by SwissXC90

Are the sensors in the housings snug?
There was a service bulletin about water entering the space between sensor and housing thus impacting the ultrasonic signals.

Google for a service bulletin...

Yes (and thanks for reply) - all sensors are snug (properly) fitted (did this myself).

The replacement wiring loom (original, but secondhand) is from a scrap yard. I continuity tested all wires before fitting.

The new sensors are from eBay, around £30 each, from a seller in Hong Kong - has good feedback, so probably not them? .Anyone know how to test them?

And is there anything else in the circuit? apart from the Fuse, the Parking Module, the wiring loom from the module to the sensors, and the 4 sensors?

[gmonag]

Do you still have the same DTC as originally?

Just because the sensors are new does not mean they work. Don't mix genuine and aftermarket sensors (not that you did!).

[Clan]

Originally Posted by nick257

Hi All, 1st post on this forum...

Have an XC90, 2007, low mileage (60k miles). Got the common "Park Assist Service Required" message about 6 months ago. The car has the rear parking sensors only. The dashboard message used to go away after rain, and returns when the car is dry!

So... to tackle the problem... bought the DICE system, installed on Win7. DICE reports "parking sensor 1" faulty.

So far.. I have :

• replaced all 4 rear sensors with new ones.
• replaced the entire parking sensor wiring loom (from the Parking Module, to each of the rear sensors).
• replaced the parking module (ECU)!
• replaced the Fuse in rear fuse panel (in boot)

Have of course reset DTCs (error codes) at each step, via DICE.

What have I missed? Is there a relay, or some other component I have missed? Any help much appreciated!

With any parking sensor problem i have found it most economic to buy the vovlo kit and replace the lot , 100% chance of it working ..
you will have to get the unique software loaded into the parking sensor control module though . It should be set for another 10 years then ...

[Caerwyn72]

With mine after replacing everything and still not working I found that the brown plug was not seating properly, so I removed it refitted it just using the black plug on the old module.
It how works a treat so not bothered putting the brown clip back just used a cable tie to hold in place🥃👍🏻