Parasitic drain on battery, suspect ECM...?

funkybeats · Post by **funkybeats** » 11 Feb 2012, 15:09

Hi,

I have been having a host of issues lately with my 2004 Volvo S60 2.5T AWD. It started with a loss a steering wheel controls for the radio and cruise control that would come back after about 30 minutes of driving. There would also be no radio lights, which would then flicker for a while and come back at the same time as the steering controls. This issue progressed into sometimes starting the car and and having no signal lights as well. I suspected the SWM (Steering Wheel module) and pulled fuse 23 to reset. This would work for the signal lights but not the radio or steering wheel volume controls. This was not a big deal to me as the car was still drivable. Now there is no steering wheel controls all the time and intermittent signal light failures which can be reset. The next thing that has happened is a parasitic drain on the battery which will take it from fully charged to dead overnight. It appears to be linked to the alarm system as when the car is not locked and the system not armed, the battery will stay charged most of the time. It has drained with the car unlocked as well but that was after I had parked it and locked it for a bout 10 munites before I got home and then unlocked it. I believe this action reset some logic in the alarm circuit and caused the drain again. The alarm siren still works so i don't believe it is a battery leaking issue in the alarm siren module. Then what I noticed is that after the car has been turned off the computer ECM is still active. I can hear it clicking away in the driver and passenger doors, not sure what it's doing but it leads me to believe that a faulty ECM is behind all of these issues (not going to sleep?).

I would appreciate any advice or troubleshooting solutions. If it is the ECM it should be able to be re-programmed as it would appear to be a software glitch not hardware since the issues are intermittent.

Anyone else have these issues? resolutions???

Thanks,

Funkybeats.

Post by **regent** » 11 Feb 2012, 15:37

Funkybeats,
Intermittent issues are more often attributable to failing hardware components rather than software. To verify your software status, you will need to have your car connected with VIDA and 'talked to'. This will reveal all ECMs' software revisions as well as possible DCT, and most likely help you see what the culprit is. Any shop with VIDA DiCE can do that; however, if there is something that requires a software upgrade, the VOLVO 'stealership' remains the ONLY option to resolve.

A lot of information can be obtained by analysing the event logs and codes (which may be set with or without CEL).

funkybeats · Post by **funkybeats** » 11 Feb 2012, 19:55

Thanks for your input, Regent. My Volvo guy (independant) just purchased the latest Volvo diagnostic computer for ~$28000. What he indicated to me is that there was a lack of communication betweeen his unit and the ECM. He didn't get into the error log findings with me. Can you buy an ECM aftermarket or is it only a 'stealership' repair?

Thanks,

Funkybeats.

Post by **regent** » 11 Feb 2012, 20:52

It depends which module you will be replacing. In general, the new ECM will need to "get familiarized" with the rest of the network in order to become functional. Reprogramming (or software reload) can be done via VIDA DiCE provided that the station has valid subscription to authenticate with the servers and be allowed to download, as far as I know.
Thank you

funkybeats · Post by **funkybeats** » 28 Feb 2012, 16:06

Bump

Anyone else ever heard of this issue?

FB.

funkybeats · Post by **funkybeats** » 31 Mar 2012, 12:17

Resolution:

Beleive it or not the problem was a faulty radio that was staying powered up after the car was turned off and draining the battery. This manifested itself into all sorts of network issues. I replaced the radio, problem solved.

FB.