2003 XC70 AWD symptoms: dash gauges and lights starting flickering and running erratically intermittently months ago, now many things don't work: speedo, tach, fuel gauge, power locks, power windows and radio (sometimes), fuel hatch and some others. Car always starts and seems to run fine but transmission seems to lurch/slip periodically too. Are all of the electronic failures the result of the main ECU going bad? Is there more than one ECU? Would the transmission malfunctions be related or is that totally separate? I want to sell the car but don't think anyone but a Volvo mechanic would buy it as is - won't be able to get emissions sticker, correct? If it is the ECU I might try to replace it myself through Volvo Ecm Prices And Ordering information For Volvo - anyone used this vendor? Thanks !

 

not likely the ECU (you noted the engine is running good and you have issues with locks/windows). Does the check engine light come on when the key is in position 2? Does it go out when you start? Have you checked your system voltage with the engine running and an electric load (ie blower/lights/rear defrost)? I'd suspect a connector or relay or ignition switch. You may bet able to see a common point via the wiring diagrams (volvowiringdiagrams.com)

 

Thanks mt, the car is currently not garaged at my house so I need to go get it this morning to run your diagnostic. If it's not the ECU, will it be difficult to trace to a relay or the ignition switch? I am not experienced in electrical problem troubleshooting.