Fried PCM

Me again. Toyota mkiv Supra 2jzgte nonvvti automatic. Engine was rebuilt and and reinstalled and has blown 2 PCMs. No fuse was blown only PCM. I'm thinking a relay could've caused a voltage spike. I'm not sure if they have diodes.

I have to wait till blown pcm is back in vehicle.

Hmm..

When you say blown, in what way? For example, injector drives, power supply, 5v ref.....

The reason I ask is that particular circuit has to be looked at, or you'll go through PCMs like Tic Tacs. There is a chronic issue that isn't being resolved.

Also, if the battery posts are switched, PCMs no likey that.

GeekDIYMechanic wrote: Hmm..

When you say blown, in what way? For example, injector drives, power supply, 5v ref.....

Exactly what I was thinking. Knowing this will help a ton as far where to start looking.

Let us know what the failure with the PCM's is, and we can speculate on possible issues.

As I said I have to wait till the blown PCM is with the vehicle again. Presently there's a borrowed working (m/t) PCM in the car which allowed him to limp home. I just shared the details I have on the situation.
Battery poles couldn't be switched because the car drove just fine for a few days, unless it was charged backwards. I did notice exposed pins on the coils but that would affect the igniter firstly.