Scanner code P0380
Hello anyone, My truck is giving only one code P0380, however truck cranks
but wont start. The code reads (Glow Plug Heater) Circuit A. I have replaced
the glow plug controller. What actually heats up the glow plugs????? The
controller or the relay??????
If the glow plugs don't get power your truck won't start. Both the controller and the relay would have to work in order for the glow plugs to get hot. There should be a fuse to check as well.
Which fuse???? There are 55 of them.
On the relay, The lead on the driver side stays hot all the time but the lead on the Passengers side stays hot only 15 seconds then goes dead? Is that a good relay or not?
Your owners manual should tell you what fuse. It sounds like your controller is working properly.
Bought used, no manual. What fuse?
Download an owners manual or pull the fuses one at a time. Since the relay is energized I think the fuse is good. You need a wiring diagram for the glow plug circuit. I looked online and could not find one.
Read somewhere even new fuses can be faulty...research how to test them...not just the 9 volt test...jiji that is partially accurate...
Having exact same problem. What did you find?
Watch - 2001-2004 Duramax LB7 P0380 Code, Glow Plug Relay, Detailed Troubleshooting and Repair on youtube
