I had the same problem with a 1998, it had a corupt flash with a checksum issue, it appears after a pcm throws a checksum code, it won't run a vehicle again, at least in 98's.

I could talk to the pcm fine, flash it, ect, I sent it to be recovered, and same thing, just cranked and no fire. Since I didn't pay anything for the recovery attempt, I just put the pcm back on the shelf to mess with later.

Ryan



Ryan

 

Hey Ryen,
where did you get your replacement PCM from? Cost?

 

I had purchased a spare one off the boards before I started messing with the one in the car, found it local for $100 , so i just put it in the car. The local GM dealer has them, $300 or so, plus a $100 core if you don't have one to turn in.

Ryan

 

So you don't have to have a PCM flashed for your particular car?
I thought it held the VIN and all that stuff ?

 

it was for another 1998 M6 car already, so I used hptuners to flash my read from my vehicle onto that pcm.

on a f-car the pcm will work with the wrong vin number no problem.

You can also use a tech 2 to do the job, if you have access to one.

Ryan

 

UPDATE !
I got a used PCM from a salvage yard, yeah it was filthy but the damn thing worked, car fired right up!

I just though I would post back on the outcome of this, in case some other poor basderd has the same problem as me.
Apparently if you write into the PCM a bad checksummed file, that PCM WILL NOT run the car again!! I sent it to be recovered and that did not fix it.
Engine would crank, and I could still read from and flash to, the PCM but it would not run the engine.
I'm going to try and get another PCM for backup, since they are a pain in the butt to find for a '98. In case this happens again. But in the meantime, I'm getting rid of LSuckEdit, and getting HPt or EFILive -