Questions and Answers

Pontiac Grand Am Blows PCM Fuse Q. Vincent: I have a 1995 Pontiac Grand Am fuel injected V-6, 119,000 miles, automatic transmission, ABS brakes, cruise control, P/S and A/C. Last winter, December 2003, I noticed the car was awful sluggish taking off, but would drive fine when up to speed on the highway. Every time I stopped and then accelerated the car was sluggish.

I could push the accelerator to the floor and it would not move any faster. Finally, I took it to a local mechanic for a tune-up. He replaced the plugs and plug wires. No help. Did the same thing. I took it back to him and he suggested I take it to someone with sophisticated diagnostic machines. I took it to one he recommended. There, the mechanic put the car on a hand-held computer.

He said it was showing an EGR valve code in the system. I had told him that the Check Engine Light would come on and go off frequently. He took it for a test drive, came back, and said he thought it was my transmission for it was taking off in high gear. He recommended a transmission shop to let them check it out. I stopped there on the way home.

The mechanic put the car on what seemed to be the same hand-held computer. we took it for a drive. He said he thought nothing was wrong with my transmission even though I was starting off in high gear. He thought I was not getting voltage to the transmission. He suggested checking my fuses.

On the way home from work shortly after that, I stopped at a transmission place a co-worker suggested to me. This mechanic hooked the car to his hand-held computer and took it for a test drive. He told me the same thing the last mechanic did, that I was starting off in high gear and that the other solenoids (?) were not picking up.

I told him about checking the fuses. As he was checking them, the fuse to the "Powertrain Control Module" was blown. He replaced the fuse. He put the car back on the computer, put it in drive, and we lurched forward. WE WERE NOW TAKING OFF IN LOW GEAR!!!

We took it around the block and everything did fine. By the way, when the fuse was shot, I had no cruise control nor air conditioning. He replaced the fuse the last week of January 2004. I drove the car for a week and the symptoms returned.

I changed the fuse, it lasted until the beginning of May and it shot again. I replaced the fuse and it may have lasted a day and a half or so. That was all I could get out of a fuse.

This past week, I would replace the fuse and as soon as I would start the car, the fuse was shot!! I am considering taking it somewhere, for the car is really unsafe as it is. I was hoping you could help me, please!!

Thanks,
James

A. This is VERY interesting to me! Aren't you glad you didn't have someone remove the transmission for this problem? Do you see how something like this could really snowball into a very large bill that didn't fix anything? Way to go for asking for more than a couple of opinions!!

The problem here is a intermittent short circuit in this fuse that keeps blowing. A dealer will/should be able to find all the components on this fuse and, by process of elimination, find the problem. Maybe chaffed wires at the transmission harness on the outside OR the inside of the transmission. Or it could be wires to anything else that is on this circuit.

You did say the A/C was inop, maybe the wires to the compressor are chaffed? Don't give up till it's fixed!