Trouble codes

12- prob w/ battery connection. Direct batt input to controller disconnected within last 50 ignition key-ons.
22- Coolant sensor voltage too high or low. Test coolant temp sensor.
34- Open or shorted condition detected in the speed control vacuum or vent solenoid circuits.
37- Torque convertor clutch solenoid circuit. An open or shorted condition detected in the torque convertor part throttle unlock solenoid circuit (auto trans only).

Those came from the Haynes manual, are you having any noticeable problems running? I would tackle those first, then run down the list if you feel you need to.

Thanks Timdog. Yeah, the old Ramcharger is acting up. It seems to be surging when I'm at idle waiting for a light to change and when I'm on the freeway, it revs up and down like it is searching for overdrive. I am going to change the oxygen sensor because it is due according to the Maintenance schedule. I'll see how that works and kind of go from there. [

If he dont' have a lock up converter then he will always have code 37 no matter what

Did the 91's ever come with the lock up converters?

Try changing the coolant temp sensor first.

Chump,
I already replaced the cooling temp sensor about 2 weeks ago. If the new one is working correctly, would the trouble code still be coming up? I thought maybe it takes a couple of weeks for the code to disappear from the computer.

Did you try disconnecting the negative battery cable for about 5 minutes to clear the computer codes?

I don't know about the 91's but my 94 has two temp sensors. One is for the computer and the other for the guage. Make sure your replacing the one for the computer if it has two.

If you go to your local auto zone they can put a scanner and erase the codes. Its better than disconnecting the battery. After the codes are erased drive it around and recheck the codes. Then tackle the work.