My '03 discovery has PDC that does not work. It has the 3 second audible alarm and blinking switch. According to the RAVE the system has a fault and this is how it signals a problem.

Also according to the RAVE, there does not appear to be any diagnostic test that can be performed. The sensors appear to be wired like christmas lights, and if one goes, they all go.

The question is: Do I just by one sensor and start replacing them one at a time, or can I test the sensor somehow?

Thanks,
Troy

 

IMHO they are not wired in series, like strings of lights. They all have a common input power, on pin one of the sensors, from pin 10 of the dedicated ECU for them. They all have a common ground, which is pin 3 of the sensors, from pin 8 of the module. So you can see if you have power to them. Each one has a signal going back on a separate wire. Not sue what voltage is on that, one would assume that it would be the same on each if there was no movement or vehicle within range. You could also meter the DC current going to sensors, to see that it is about the same for each one. If you have more advanced test equipment, like an oscilliscope, you can compare signals from each sensor. Of course, it could just be a bad module.

 

PDC is fixed!!

Just thougth I'd post the solution on here so future searches might turn up something useful.

Ran through the usual and checked fuses, connection etc. I accidentally left the PDC switch on, and went about taking the wiring loose from one of the sensors. I must have moved the wire just right and I started to hear clicking coming from two of the four sensors.

I then wiggled the wire harness and the clicking would stop, then start. So I knew I had a wiring issue. I took off the wiring loom and found that one of the common wires (white) was barely spliced together. The splice that was bad, was in the loom between the two driver side sensors.

Seems the factory put a splice there for the common power or ground (didn't check which). It had one metal crimp with very poor tape over it. It appeared to be factory, but it obviously did not survive the salt they put on the roads up here.

Patched it back together and it works great.

Thanks,
Troy