I have an 04 XC90 2.5T FWD with 60K miles. At random, the lights will flicker and then the entire car shuts down electronically for a split second. This causes the entire car (engine) to shut down for a second, jerk and then come back on. When it comes back on, the Brake Failure and SRS lights come on and stay on. I've been to the Dealer 4 times and the codes simply read communication failure. They've replaced the ignition switch b/c we thought it was losing the connection and causing the shut down, but it continues. We've just replaced the battery b/c one of the cells was not at full power. Beyond that, the dealer has no idea. Their next recommendation is $630 to replace the electrical distribution box in the engine bay, but they don't know whether or not that will work. They looked in the steering column and at the main computer brain and saw no signs of water or corrosion on any wires.

Any thoughts?

 

It COULD be a bad grounding wire-seem like it loses power all together-then it should be lost (+) positive contact near battery/alternator, or possibly bad (-) negative wire from battery to chassis. I'd pull neg. battery cable and feel it for breaks under insulation...
good luck-let us know if u fix it and how.

 

Thanks! It's been about 200 miles since they replaced the battery and it hasn't happened again (knock on wood). Perhaps replacing the battery corrected any problems with the positive or negative cables / contacts. I will definitely check. Thanks again.

 

sometimes the terminal on the battery will become lose-seems OK until you pull on it-and it will come out easy-happened to my friend.

 

I have an 04 XC90 2.9T with 60K miles. At random, the lights will flicker and then the entire car shuts down electronically for a split second. This do not cause the entire car (engine) to shut down, but folliwng the lights problem, SRS lights come on and stay on . Did somebody face something like that?

 

Couple of questions for you since i have seen something like this in a 04 S60 i worked on.

• Do you ever have small children in the car?
• Did they get access to the CD Changer?

Reason i ask those crazy questions is, i had a friend chasing a shut down, guage cluster dies, and a whole bunch of other issues because of $0.73 quarters, dimes, nickels and pennies were insterted into the changer.

Dont know if this case applies to you but that is what i have seen LOL

I replaced the cluster but problem still existed, one day the radio dies finally and we go to replace it and find all these coins inside and that solved all our problems.

One more thing for thought: did you have this car from the beginning? do you know of its service history? what areas were "serviced? it maybe a clip to a fiber optic cable or even a harness loose. climate modules will cause keyless and lighting issues. i know that from experience. Also does the service srs urgent come on?

 

your volvo dealer must be a moron