Hi there,

Was out for a weekend blast yesterday and mid overtake of a few Sunday cruisers saw my PCM die. On investigation I found the 10A fuse on that circuit had blown, so bought a 5 pack at a local gas station and replaced. The first couple I put in immediately blew, so waited 10 minutes for the car to 'turn off' properly and replaced with a third. This one worked for about 10 minutes, but then it died as well.

Before I start troubleshooting (I'll remove each device on the circuit and test), has anyone else had a similar problem and/or know of a simple solution? I would appreciate your help.

Thanks,
Jake.

 

Any aftermarket electronics hooked up to it?

 

Yep, have a Dension 500S BT in line with PCM power, but removed this after the first fuse popped as it seemed a likely cause. Has been installed for months now and running with no problems.

 

Fuse blowing indicates an electrical short in all likelihood. Replacing the blown fuse without fixing the cause will never resolve things.

Someone had a short between the speaker inputs for one of the speakers - that short on the amp power out caused the fuse to blow. I suspect a connector/wire damage going into the PCM is most likely the culprit (check wiring in doors (speakers), dash (speakers) and connectors to the PCM. Not likely internal to the PCM.

A diagnosis path is unplug external things from the PCM, power it on and see if its good. If good, power down,plug in one more item. Power up.. is it good, repeat till you get the blow. Now you know what item caused the fuse to blow - the last thing you plugged in.

 

Annoyingly the fault is intermittent and not limited to the PCM.

Ran fine for three days then faulted again when I hit 4000+ rpm. Today the memory function buttons on the door stopped responding at startup. After a minute of driving they started working again.

Also, the centre air bag in the lumbar support in the drivers seat inflated to full. Pressed the deflate button to stop it.

Also seemed as though it wouldn't turn over when I first turned the key (like I hadn't depressed the brake). Unsure if it was just that I hadn't pressed on it, was in a rush.

Yay for electrical faults.