Help! Parking Sensor Issue Audi A6 Allroad

[mikelima]

Hoping someone can assist!

Two front parking sensors on passenger side were not working (not 'ticking' when you put your ear against them - all the others were fine. Ordered two replacement sensors, took off front bumper, replaced old sensors with new - still no 'ticking' from the new sensors and parking sensor warning light came on (as it normally does when faulty sensors are identified). Swapped working sensors from drivers side (just in case the new sensors had a problem) these didn't work on the passenger side. The sensors I'd replaced as faulty did work on the drivers side.

So the conclusion is that the problem is not the sensors. Any other ideas?

[cuprabob]

As you've proved the sensors are OK, then it really can only be the wiring or the control unit. I would check the connector where these particular sensors plug into the control unit and the wiring between them.

[drdino]

You've done A-B-A testing and confirmed it's not the sensors. Next step is to prove out the wiring; do a simple continuity check from the sensor's connector up to the control module. If that's not ok, you need to break it down and start from the sensor connector up to the next inline connector and so on, until you reach the park aid module. You can check for obvious things such as chafing in the wires, signs of moisture in the connectors etc. Can you get the codes read? If the module's diagnostics are well-developed, it should set appropriate DTCs.

[Adrian E]

Fault code memory will store DTCs for the parking sensors, down to the exact faulty one (or wiring to it), or the control module.

I seem to recall that, at least on the front, the inner and outer sensors aren't the same? Could be my memory as it's a while since I had to have some replacements for our C5 A6

[mikelima]

Thanks chaps.

Did continuity testing on the wires which seems OK. I don't have a code reader - may invest in one to see what the issue is, but it sounds potentially that it's the parking module...