I pulled code 37 (lock-up solenoid fault or baro read circuit fault) off my 88 RamCharger. Unfortunately I don't have the Haynes manual with me and have no idea where the parts are or what they look like.

This occurred after a severe rain, so the humidity might be giving me some spurious readings. In the event that it is merely exposing an already faulty lock-up solenoid or whatever, where do I find the lock-up solenoid and what does it do?

Thanks in advance for any help.

 

I have two sites I check Diag codes on and both say this.

Site #1

37 Shift indicator light failure, 5-speed
OR
part throttle lock/unlock solenoid driver circuit (87-89)
OR
solenoid coil circuit (85-89 Turbo I-IV)


Site #2

37 On 1988-89 models, part throttle unlock solenoid circuit.

I'm not sure if it's talking about the starter solenoid being bad or something else. I found another one with similar problems. Check the link out below. I think it will clear it up for you.

Throttle Solenoid Post

 

Thanks, I'm going to check the wiring when I get ahold of the manual. You're diagnostics help clarify the lock-up solenoid text that I was stuck with from my analyzer.

Yesterday, as per my suspicions, both trouble codes disappeared and the truck ran a lot better, because the rains are now a few days in the past and the truck seems to be drying out.

I've already had to do extra work to prevent water infiltration under the hood, but some still seems to get in. It was so bad when I bought the truck that it would barely run after going through a car wash. Now it's a little better, but a day or two of pouring rain will bring out the problem again.

 

it is a false code. that truck does not have a lockup torque converter. the computer is looking for something that does not exist. all those computers were programmed for it; If you have a non AC truck you'll get a code about not seeing AC engage/disengage as well. Your check engine lite wont come on for that code.