LB7/LBZ/LLY/LMM - Intermittent Driveability Conditions-No Crank, Crank No Start, Hard to Start, MIL/SES, HEsitation, Lack of Power, Surge, Misfire, Fuel Knock, IPC Indicates No Oil Pressure, DTCs Set

This bulletin is being revised to update the model years and add Condition and Correction content. Please discard Corporate Bulletin Number 04-06-04-001B (Section 06 -- Engine/Propulsion System).

Some customers may comment on any of the following various intermittent driveability conditions:

Various engine faults or DTCs may occur due to backed out pins in the following main engine harness connectors:

The main engine to chassis connectors utilize a plastic tab formed into the connector body as a terminal lock (5). If a terminal lock (5) is damaged or broken, the terminal (1, 4) will be pushed partially out of the connector body (2, 3) during assembly and will make poor or no contact with its mating terminal. Various and intermittent engine control faults may occur.

Notice: When reconnecting the engine to chassis connectors, slide the Primary Lock Reinforcement partially out of the male side connectors to support the ends of the male pins upon installation. Guide the chassis side connectors straight into the engine connectors when using the lever lock to avoid terminal misalignment. Failure to do so may cause terminal lock breakage.

Inspect the terminals in the male and female sides of the connectors for broken terminal locks by removing the terminal position assurance (TPA) comb at the back of the connector (if equipped) and gently pushing and pulling on the wire in question. If the wire moves within the connector and does not lock into position, the connector body should be replaced.

Connector Location

The following connectors are all located at the engine harness to engine chassis harness that is mounted to the top of the driver side valve cover.

If an illustration is needed to locate the connector in question, please refer to SI and build your vehicle publication to view. Then select the following areas:

1. Body
2. Wiring Systems
3. Component Location
4. Master Electrical Component List

Connector Components

1. Terminal Position Assurance (TPA) (C107 and C118 only)
2. Cable Seal
3. Female Terminal
4. Lever Lock
5. Connector Body - Female
6. Connector Seal
7. Primary Lock Reinforcement (PLR) - Female (C108 and C119 24-way connectors only)
8. Primary Lock Reinforcement (PLR) - Male (C108 and C119 24-way connectors only)
9. Connector Body - Male
10. Male Terminal
11. Cable Seal
12. Terminal Position Assurance (TPA) (If equipped)

The 6.6L diesel engine utilizes a 24-way and a 38-way Packard Lever Lock GT Series sealed connector for the engine to chassis connection. Connector components can be serviced using the J 38125 Terminal Kit. Connector bodies are available through GMSPO. The following components are available from the J 38125 Terminal Kit:

Important: If the correct terminals are not found, verify that the tray numbers have been updated.

For vehicles repaired under warranty, use: