Hello. Any one got experience with electrical connections to transmissions? Got 1991 Ram D250 5.9L gas 2WD automatic (A518 trans). Computer is flashing fault code 37 for "torque converter lockup solenoid" or "part-throttle unlock" solenoid problem according to Chilton's manual, but there's no troubleshooting tips and I can't find wiring for those solenoids on the transmission. Any tips?

 

If you can't find the electrical hookups on the tranny they may not be there. My 89 has had that code since it rolled off the show room floor and I don't have a part throttle unlock solenoid. If your truck has one it will be the rear most relay on the drivers side fender just under the hood spring. How many relays are there on yours? There could be between 2 and 4.

 

Thanks for the quick reply. There are 3 relays on the driver's side inside fender. I'm thinking I don't have the lockup converter solenoid, either. Just found a web site featuring a scan of a tech/service bulletin on A500 and A518 transmissions - it mentions the A518 may not have got the lockup converter solenoid 'til 92, while A500 had them earlier.

 

I have a recent Chilton's and it lists the code 37, in addition to what you guys mentioned, Trans Temp Sensor Voltage Too High or Trans Temp Sensor Too Low. My old Chilton's and Haynes book missed a lot of things so I bought a recent one. Hope this helps.