A few years ago my check engine light came on. Using torque pro, code P0671 (number one glow plug failure). Since the truck didn't have any problems starting up, I lived with the light and I would just check for new codes. Following diesel truck Ron, I checked all the wiring first, no loose connections. Then I checked it with an amp meter all was good. I ended up replacing the Glow Plug module on the valve cover. Not the solution. I dug deeper and when I removed the inner fender I observed that two the four harness connectors were broken. So, I put in a new #1 glow plug and a new harness. I cleared the codes and the same code came back.

The only other unusual thing was I had a really mild 65 horse tune with a transmission safe tune placed on the ecm before the light. Is there ANY way the two can be connected? If so how?

I am thinking about selling the truck in the future, but I won't sell it with a check engine light on.

Thanks in advance for any help or input.

9905

 

 

Not questioning your ability but I have to ask, did you change out the most forward passenger side glow plug and harness? On this engine cylinders 1, 3, 5, & 7 are on the passenger (right) side.

 

LOL, no problem, I definitely checked before doing the work.

 

No, I replaced the glow plug module first. I am just grasping at straws now.

 

 

I found the Glow Plug PDF I thought I had. Hope it helps.

 

Yes. I am sorry, I had to look up what you were saying. I am not sure what the harness from the module is called, but I would assume that would be where my fault is because I have pretty much just replaced all the other parts besides that.