PCM Programming Concern - keywords 3.8L BCM communication control driveability engine error L26 L32 message module operation performance program tech2 TIS

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Worldwide Service Programming (WSP) group has identified a condition that occurs during service programming of the PCM. During programming, if another module transmits a class 2 message, it will interrupt programming of the PCM; this occurs approximately 1 out of 3 times the PCM is programmed.

Fortunately, this condition does not result in damage to the PCM because of the boot software used on the PCM. In other programs where boot software was not as robust, often the PCM would require replacement if programming was interrupted.

Do NOT replace the PCM. You can restart programming the PCM and complete the service as normal. If the second attempt to program the PCM fails, the technician can go to SP205 which is located next to the DLC. Remove the splice pack comb and jump terminals A, B, and M (Refer to eSI Document ID # 1458046). Then restart programming of the PCM.

Typically in cases like this, the WSP group would advise pulling the fuse on the BCM, to prevent interruption during programming of the PCM, but there is no longer a dedicated circuit that powers the BCM (five power supplies to the BCM). With the fuses removed, the BCM is off line and so is the rest of the vehicle, so that method will not work on this vehicle.

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.