Newbie Code 37 question
 

I get two error codes on my 1988 Y-code 5.2L Ram W100. A code 15 "No speed/distance sensor signal" and a code 37 "part throttle lock/unlock solenoid driver circuit (87-89)". I found the speed/distance sensor but I have no idea where to look for the lock/unlock solenoid driver. My Haynes manual is no help. Any thoughts?

Also, could either of these codes be the cause of my truck nearly stalling at stop lights when warm?

Thanks,
Monty