This is sounding more like a bad PCM.

Answered by Wrenchtech (expert)
14,757 answers provided

What is the best way to verify that the PCM is failing ?

Answered by mccaw
2 questions asked

That can be very difficult because there is no way to prove a PCM is at fault. What you have to do is verify everything in and out of the PCM, including all power supplies, grounds and sensor inputs.

Answered by Wrenchtech (expert)
14,757 answers provided

I dont no if this helps but i replaced the PCM relay and the engine doesnt cut out any more. But it does still dies completly after about 2 miles becoming more frequent the more it is driven. Logging a code for the mass air flow sensor everytime and not restarting until the code is cleared. Once the code is cleared it runs fine until it acts up again. I have also noticed that if I keep a steady speed it will quit running everytime. But if I run it up to 60 mph let it coast down to 50 mph and then back up never staying at a consistant speed it will not quit running . When it does Quit running its like the key was shut off no miss, hickup , or ruff running

Answered by mccaw
2 questions asked

You are going to have to somehow determine which function drops out first at the split second as the engine dies as to spark, injector pulse, fuel pressure. It's not easy but that is the route that has to be taken.

Answered by Wrenchtech (expert)
14,757 answers provided