Gentlemen,

I have an issue with a rear diff electronics. When it's wet or the car was staying on wet when I turn ignition on I have three lights poping up (diff error). But if I turn ignition off and then on - it's gone. And it happens when it's wet only (car itself is wet, not driving on a wet surface) so I suspect it's some electrical issue. Where should I check? Is there any diagram of diff wiring?

Thanks!

Anton

 

you should check the connectors on the ACD/AYC pump, located under the trunk. Clean them, you might have some water inside and the ACD ECU might think there is something wrong with the pressure sensor or valves. There are the connectors on the sensor and valve itself + a big connector on the pump housing that connects all those wires to the main harness...

 

i believe its the center diff your talking about not the rear one. a dealer can read the codes from those lights being on and should be able to tell you whats wrong with it.

 

I've checked them but it does not help Could it be some main harness in front or middle?

 

Rear... AYC codes say "short circuit" but the issue goes away after restart so very difficult to trace and fix.

 

you can check the connectors in the kick panel on the right of the passenger feet...

 

OK, so I've managed to read the AYC code - it's "74"

74 Proportioning control valve system Broken wire or short

Any idea where to look?

 

check the connector on the proportioning valve on the pump (cylinder shaped valve sticking out)... then check the resistance on the pins on the valve itself...

 

if you have ayc, you will have two proportionig valves... check them both, those are the valves with just one connector..

 

Got manual with step-by-step guide. Will do on Monday. Thanks for pointing in any case

 

Checked wiring with oscilloscope - no noise. Replaced valve with a 100% working one. The same result Any other ideas?