Duramax Owners

[Exnavydiver]

Dennis, we will be in Linden which is 200 plus miles west of Knoxville. Thanks for the info though. We will be spending the winter there... Dave

[EagleRunner]

I recently had a problem with my 05 Duramax. The check engine light illuminated, the fuel guage dropped to empty and the low fuel indicator lit. The engine dropped into limp-home mode and that allowed me to pull off the road. I had a half tank just seconds before this problem surfaced. After checking everything out and restarting the engine several times, the engine returned to normal and I was able to complete my trip to the nearest town. After refueling, the check engine light went out and the fuel indicator and gauge returned to normal. The problem went away, so I thought, until about four months later, when it resurfaced. The problem turned out to be due to wire chaffing of the wire harness to the Fuel Injector Control Module FICM, shorting the harness to the metal harness saddle. The wire harness is secured to the top of a medal saddle with no protection to the wires. Constant vibration of the engine eventually chaffes the harness enough to cause a short. This particular circuit controls the entire right bank of injectors (cylinders 1, 4, 6, & 7). The codes stored in the PCM indicated faults to each of the right bank injectors and their main control circuit, five fault codes in all (P2146, P0201, P0204, P0206, & P0207).

Wire chaffing of the FICM harness is a common problem, not only with the Duramax, but also with Fords and Dodge engines as well. On the Duramax, you might want to check the harness to see if you have similar chaffing problems. The wiring harness saddle sits adjacent to the alternator, on the same mounting frame as the alternator mounts to. The harness plugs into the side of the FICM. I cured the problem by simply removing the wire tie securing the harness to the saddle and taping the harness where the wire was chaffed. The harness is tight enough that removing the wire tie to free the harness from the saddle is not a problem. Since implementing this repair, the problem has not resurfaced. Why the manufacturer did not use a rubber insulator on the saddle to protect the harness is a mystery.

I hope this helps those who may experience the same problem.

Tom