I’ve looked everywhere for the little blue 2 port diagnostic cable and i don’t have one. no obd port. nothing. i have a p75 obd1. I just want to pull my cel codes because it’s running horrible and don’t have a clue where to start. If anyone has any wiring help or ideas please let me know. Cheers.

 

The service check connector is just a ground on one pin and a wire to the ECU on the other. Double check by looking up the specific pinout, but SCS pin on the ECU should be D4. Grounding that pin is the same as jumping the blue service check connector.

 

You were spot on it’s D4 i’m gonna check it out tonight when i get home. I just ground it out to the car or do i have to ground it to something specific? (probably a dumb question)

 

any ground should work as it's just to signal the ECU by pulling that pin low. if you want to be real particular you can look up the ground distribution and find the factory ground point to connect to.

When I was young I didn't know much about electrical and probably asked similar questions. better to be a little cautious while you are first learning.

 

it's right under the steering wheel

 

The 2-wire service connector is actually in the engine bay... it is a yellow plug on the headlight harness bundle just in front of the shock tower close to the fender wall.