Will it talk to the computer?

 

i can read codes and see certain live data and do data logs with it. it’s a Carlyle tool from napa. so i guess my answer is yes ? sorry

 

See if the PCM is even attempting to activate the ASD relay. Do you have wiring diagrams for your truck?

 

i do not

 

Grab the service manual for your truck from here. Wiring diagrams are in section 8W.

 

so the idea is if neither relay gets a constant 12V source then the pcm is likely bad?

 

Both relays should have 12 volts on pin 30, at all time. Both relays will have 12 volts on pin 85 with ignition On. PCM controls ground side of the relay control circuit. (pin 86).

 

okay so what will i see then if it’s the pcm that’s what i’m not understanding? voltage on pin 86? no voltage on 85?
electrical is my kryptonite so i’m trying to learn on the fly before i drop all that money on a shop. i appreciate all the help

 

The PCM should ground pin 86 for a few seconds at initial key on, or, when the PCM sees the engine turning. (crank sensor signal) You can test that with the relay out, and a second warm body makes it a LOT easier.

Verify you have power in the right places first though. (relay socket.)

 

no power ever came through the 86 pin, it always stayed ground. constant at 30. both the ASD and fuel.