p0381 code

[trashygasman]

I keep tripping a p0650 error indicator lamp (MIL) control circuit error, and a p0381 glow plug indicator circuit error. Does anyone know what might be causing this?:noidea:

 

[tinman22]

did you have the GPCM recalibrated? there was a recall on the 06 trucks for soem issue with the glow plugs not sure if it was for the particular problem your having but its worth looking into. not sure on the p0650 though

 

[trashygasman]

I have had it recalibrated. I think the 2 codes go together. When the glow plug indicator doesn't work, it trips the indicator lamp malfunction. I think...

 

[trashygasman]

any more idears?

 

[tinman22]

maybe theres a short somewhere in the glow plug system? not sure I havent ran accross this problem before

 

[trashygasman]

That's kind of what I was thinking too. Just looking to see if someone else has seen it before. Thanks

 

[tracker954x4]

Take a look at this

#PIP3603C: Diesel Engine Equipped Vehicles With P0381 And P0650 - keywords 6.6 6.6L glow glowplug indicator instrument LBZ light LLY LMM panel plug start wait - (Apr 22, 2009)

Subject:Diesel Engine Equipped Vehicles With P0381 and P0650

Models:2006-2009 Chevrolet Express, Kodiak, Silverado
2006-2009 GMC Savana, Sierra, Topkick
Equipped with the 6.6 LBZ LLY or LMM Diesel Engine​

This PI was superseded to update models and model years. Please discard PIP3603B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
<A href="#ss1-2266700">Condition/Concern:​

The dealer may encounter a customer concern of a SES light with the Wait to Start Control Circuit DTC P0381 or P0650 Malfunction Indicator Lamp (MIL) Control Circuit found.
<A href="#ss2-2266700">Recommendation/Instructions:​

If the DTC P0381 code cannot be duplicated, and it's only found as a history code, clear the DTC and evaluate the concern.
Engineering has been involved and investigated P0381/P0650 codes.
In most cases DTCs P0381 and P0650 will occur after a repair, during a radio upfit, an add-on dash switch modification, or upfitting of other aftermarket components.
For GMT900 Light Duty Trucks and GMT610 Vans:​

1. If P0381 and P0650 have set together after some type of electrical or under-dash repair, clear the DTCs and verify they do not reset after cleared. If the IPC is unplugged and the key is cycled once you will set P0650. If the key is cycled a second time P0381 will be set along with P0650. If the power feed to the IPC is lost both P0381 and P0650 may set.
2. If DTC P0381/P0650 was not set before initial repair/modification, and only starting setting after repairs were completed, the repair needs to be rechecked. Connections and wiring to IPC (instrument panel cluster) should be inspected and repaired. If modification was made to original wiring harness it needs to be removed and setting of DTCs evaluated.
3. If P0650 is set by itself and was the original vehicle concern, complete the current SI diagnostics. ECM replacement is not suggested for P0650 set by itself. ECMs returned and inspected by engineering have been found no trouble found. Most P0650 codes have been repaired by either a wiring or IPC repair.

For GMT560 Medium Duty Trucks:

1. If P0381 has set after some type of electrical repair, center console repair, or under-dash repair clear the DTCs and verify they do not reset after cleared.
2. If DTC P0381 was not set before initial repair/modification, and only starting setting after repairs were completed, the repair needs to be rechecked. Connections and wiring to IPC (instrument panel cluster) should be inspected and repaired. If modification was made to original wiring harness it needs to be removed and setting of DTCs evaluated.
3. If P0381 is set by itself and was the original vehicle concern, complete the current SI diagnostics. ECM replacement is not suggested for P0381 set by itself. ECMs returned and inspected by engineering have been found no trouble found. Most P0381 codes have been repaired by either a wiring or IPC repair.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.​

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[trashygasman]

Thank you very much! This winter I replaced the hydroboost. After that I had a short in my brake switch. This is when the codes started. I replaced the brake switch and wiring harness, but I still have the codes.

When it first does it, the tach will jump around and the blinkers and a/c compressor won't work. Then the CES light will come on after about 3 key cycles and everything starts working right again. I can clear the codes with my programmer, but then it will do it again in a few days. It's some funky schtuff.