2004 XC70. My first Volvo

xplus93 · Post by **xplus93** » 21 Oct 2018, 17:57

I finally got a Volvo wagon. I've been wanting one for years and haven't been able to afford it. I decided to get one with issues and fix it up myself.

The major issue i'm facing is a battery drain and odd behavior whenever I try to start it. I tried to look it up, but it's pretty odd and tough to find information about.

When I exit the car and it's left to sit for a short amount of time the remote will no longer work, and the lights will no longer come on. Attempting to start the car normally I get no information on the LCDs on the DIM and it stalls shortly after starting. It then takes a few attempts to get it to start up. However, If I turn the key to position II, turn it off and then back to II I am able to start the car normally. I still have a siren communication fault in the UEM. This car had this issue when I bought it, but I think I remember it going away while fixing other issues. It may be that I never left it long enough for the problem to appear again. I also have an airbag warning light on, but no related codes in VIDA.

When I first got it I had a PDM communication fault which I traced to a loose connector in the door hinge. I believe this has been resolved since I no longer get the error in VIDA.

I also had a CCM fault which was repaired by installing a new blower resistor.

I resolved a problem with the tail latch not working by manually moving and resetting the servo.

xplus93 · Post by **xplus93** » 09 Dec 2018, 18:51

Update, the fault with the PDM (or at least the door connector) has not been fully resolved. I noticed the speaker was not working in the passenger door and wiggling the interconnect made it go in and out. This makes me think that the communication with the PDM must not be working as it should and is the cause of the issue. The issue seems to be with the security system/immobilizer from the symptoms. I will be putting in a new siren module and door harness this week. I'll update when done.

Ironically now that i'm finishing up with this there is a chance i'll be getting a V70R this week.

EngineeringBloke · Post by **EngineeringBloke** » 10 Dec 2018, 19:45

The speakers in the doors are connected to a pair of speaker wires that runs back from the speakers to a plug at the radio head unit. There are pairs going to each of the 4 doors. If a Volvo amp is present, then that plug is not connected to the speaker output of the head unit but instead is plugged into an inline socket that runs from near the head unit to the amplifier under the passenger seat (Plug and play).

It is unlikely they are involved with the PDM unless the insulation is stripped at some point and shorting to the CAN bus to the PDM.

If you get the V70R, enjoy. They look like amazing cars.

xplus93 · Post by **xplus93** » 11 Dec 2018, 01:10

Yes, but if you look in the wiring diagram at junction 54/11 that includes connections to the PDM, CEM, AUM, door lock, and battery. I noticed a fault in the harness about 6 inches in from that junction inside the door where movement causes the speaker to drop out and the PDM to turn on and off.

EngineeringBloke · Post by **EngineeringBloke** » 11 Dec 2018, 18:59

Thanks, that's interesting. Can you describe the fault in the harness and its possible cause? Is the issue with wires or a plug?

xplus93 · Post by **xplus93** » 11 Dec 2018, 19:03

It was a wire problem. There was impact damage on that door. It looks like some ape was messing around with it. It seems like the problem is resolved. I don't get any PDM communication faults and all of the equipment in the door functions. Well, I think. Not sure how to test the connecting between the locking mechanism and the CEM.

xplus93 · Post by **xplus93** » 11 Dec 2018, 19:09

However the final remaining problem is very annoying. I'll try to describe it as best as I can.

1. I am able to lock/unlock car with remote. Lights come on when door opens. Red security system light on dash blinking.
2. Leave car for more than a few minutes
3. Return to car. Red light no longer flashing. Cannot unlock doors with remote
4a. If I turn the ignition straight through II all the way to III and try to start engine it will stall. No information shown on screens on DIM
4b. If I turn key to II, back to I, then to II again the car acts as it should.

xplus93 · Post by **xplus93** » 19 Dec 2018, 06:45

Ok, so I did get everything working fine in the door. No audio dropouts or communication problems with the PDM. But the problem is STILL not resolved. (Plus the guy with the V70R was a jerk, so I ended up not getting it) Can someone with experience PLEASE hep me. The post above describes in detail what is going on with the car and I have no clue how to type that into a google search and get anything relevant. Been trying for months now and I need this car running next month since i'm going back to college and starting classes.