Hey all, my father bought this car with damage from an interior fire. I come from the oldschool VW world, and am unfamiliar with these complex, computerized machines, thus I am doing this in hopes of helping him out. It looks like the wiring harness going from the interior fuse-box to the sunroof and vanity mirror had started this fire, as it was the only wiring which was found to be damaged. The damage extended right to the fuse-box itself, however, no other wires were affected. Only the sunroof area was affected by the fire. Currently, I have been trying to get the car started, as everything else will be a cakewalk in comparison.

So far I have swapped the fuse-box/ecu with a known working one from an equivalent, 06 model. When using the corresponding ignition key, I am getting an immobilizer warning from the trip computer. I can hear an electric pump (power steering?) of some sort turning on inside the engine bay, but the motor itself refuses to turn over. There is no audible evidence of the steering lock disengaging, and the stereo isn't turning on either. The windows all have power, but the front ones refuse to go down for some reason. They act as if they are physically locked in the up-position, although the motor does respond to the command.

Can you please explain to me which modules affect the starting of the car? Being an electrical fire, some of the sensitive circuitry might have been damaged, without physically appearing to be. I need some guidance, as I am now completely out of ideas. Any help is kindly appreciated.

Thank you.

 

rocad, the starting system/immodbilizer is a distributed system where several of the electronic modules are paired together. Of what I know, the CEM module is paired with the SCU (The ignition where the key goes) and keys at the factory. Though, I believe a dealer can perhaps program additional keys into the CEM. The CEM communicates with the ECU through a CAN bus telling it if it should start or not. At the very least, you would need to find a matched SCU and CEM from the same car. The CEM can be found below the glove box in the foot-well. Hope this helps.

 

Cheers for the help! After some heavy researching, it seems like the key, ECM, ECU and steering lock module all need to match in order for the car to start. I will try swapping the missing parts and report back with my findings.

 

I am having the same exact problem but no components were changed other than the wiring harness. I have an 05 s40 2.4i and changed it with one from a 2008 v50 that came with the engine I swapped out. Car ran fine but decided to put newer harness on and bow it won't start.