Last time I posted a message about this subject I was getting a Trouble code 22 which is throttle position sensor reading low and a Trouble code 26 which in my repair manual is a quad driver circuit #1. Fuddyduddy121 told me there was four things I should check 1. Charcoal canister purge solenoid 2. Hot temperature lamp 3. Low speed fan relay 4. TCC apply solenoid. I decided to replace the charcoal canister purge solenoid when I did that my trouble code 22 stopped coming up so that solved one of my codes now I am wondering if having that charcoal canister purge solenoid bad for so long caused the quad driver to malfunction for good. And possibly would I just need to replace the computer any suggestions would be great. Thanks for everybodys help.

What is the year and trim line of your car?

What problems are you experiencing now?

1992 Pontiac Bonneville SSE - Not Supercharged
The service engine light goes on and off as I am driving I have notice it mostly comes when I am going either right around 35mph or around 55mph but when the service engine light does come on the engine kind of hestitates a little. Every once in a while I will come to a stop and the engine will quit but I can start the car right back up.

What are the codes you are getting now?

It doesn't seem like one of the other three issues.

sorry about not replying quicker I am just getting a trouble code 26 which in my chilton manual is a quad driver module circuit 1 bad. It is kind of weird that the service engine light flickers on and off at different speeds you would think it would stay on at all times thats what other trouble codes usually do. I was getting a code 21 throttle positon sensor high but when I changed the canister purge valve it stopped bringing up that code. So you guys think it has something to do with the tcc what part exactly do you think I have to replace. Thanks again for your suggestions.

Here is the thing:

When you get the Quad driver code in addition to other codes, you are supposed to fix the other code problem first, and then check to see if the quad driver problem goes away.

I would have started by replacing the throttle position sensor first. Interesting how replacing the charcoal cansister valve fixed that.

Anyway, you need a good diagnostic to isolate the cause of the quad driver fault. Do you have a service manual? It'* very possible it is the TCC solenoid, but you can't say for sure.

One place you can start is by checking the wiring to the transmission. See if it is burned or chewed by mice or something like that.