Electrical Gremlins - 2002 XC 70

lukaniuk · Post by **lukaniuk** » 23 Nov 2016, 18:33

Hello all,

I need help diagnosing an electrical issue with my 2002 XC70.

The DIM stopped working, only the check engine light will come on when I first turn the ignition, but will disappear when the car is running. Everything else in the car works normally. The radio, the AC, the windows, the power locks, lights, signals, everything works and it runs and drives like it should, just no DIM.

I tried replacing the DIM with a good used unit. That didn't work.

I had the original DIM repaired. They re-soldered, put in a new voltage regulator, replaced some lamps, and another component, but I can't recall exactly what it was. Still didn't work.

I suspected the CEM, however was told this would be very unlikely because everything else in the car still worked as it should. Also, I am not able to measure resistance between pins 6 and 14 on the OBD2 port, which I understand is supposed to measure 60 ohms. There is no connectivity between these two pins. I figured this failure of the CAN would be because of a problem in the ECM.

I found a good used ECM and sent it away with the original to Xemodex. I just got it back. DIM still doesn't work.

What to try next?

beigg · Post by **beigg** » 23 Nov 2016, 19:20

If you wiggle or slightly turn the ignition key back or forward in the run position, does it change anything?

lukaniuk · Post by **lukaniuk** » 23 Nov 2016, 20:31

wiggling and playing with the key doesn't seem to help. Is this something that commonly goes?

beigg · Post by **beigg** » 23 Nov 2016, 20:34

Not that im aware of. DIM is usually a dependable part.

lukaniuk · Post by **lukaniuk** » 23 Nov 2016, 20:41

I mean the ignition switch. Is there a way to test this if I pull the rest of the steering column apart?

Post by **abscate** » 24 Nov 2016, 06:27

You need a VIDA connection to sort out P2 modules, or else you will go around and round in troubleshooting hell

Post by **oragex** » 24 Nov 2016, 06:55

Also measure the alternator charge and check for cracks in the power cable. If charge is low or if the bearing is seizing (a/c compressor pulley has similar tendency), it will cause weird electronic issues.

Otherwise I still suspect the DIM. Mine had some tiny resistances blown. Maybe get it to another shop? The replacement DIM had the same numbers on the side and was from a 2001-2002 car ?

Post by **chrism** » 24 Nov 2016, 07:27

This sounds like one of those cases where might be money ahead to go have a system scan at the dealer or well equipped Volvo independent. Otherwise you will soon have more money invested in playing musical parts than the car is worth.

beigg · Post by **beigg** » 24 Nov 2016, 09:56

abscate wrote:You need a VIDA connection to sort out P2 modules, or else you will go around and round in troubleshooting hell

Sorta off topic, but I have to ask.

Is there a meaning to the "P" in "P2"? What does the "P" stand for? Short for a word or short for a phrase?

Post by **abscate** » 24 Nov 2016, 10:58

beigg wrote:
abscate wrote:You need a VIDA connection to sort out P2 modules, or else you will go around and round in troubleshooting hell
Sorta off topic, but I have to ask.

Is there a meaning to the "P" in "P2"? What does the "P" stand for? Short for a word or short for a phrase?

Thats a deep Volvo Guru question that is out of my league, but Im sure someone here knows the answer

My semi-educated guess is that the Swedish for 'platform' might be the answer - platform is the often used phrase for models in the automotive sector.