C 2500 Truck 2WD L6-292 4.8L (1986)
Relay Module: Customer Interest
Electrical - MIL ON/DTC's Set By Various Control Modules
Bulletin No.: 09-06-03-004D
Date: December 08, 2010
Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control
Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant)
2011 and Prior GM Passenger Cars and Trucks
This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control
sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal
surfaces is sufficient to correct the condition.
This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C
(Section 06 - Engine/Propulsion System).
Some customers may comment on any of the following conditions:
An intermittent no crank/no start
Intermittent malfunction indicator lamp (MIL) illumination
Intermittent service lamp illumination
Intermittent service message(s) being displayed
The technician may determine that he is unable to duplicate the intermittent condition.
This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical
contact surfaces of the connection or connector. This may be caused by any of the following conditions:
Poor connection/terminal retention
A connector, component or wiring harness not properly secured resulting in movement
On low current signal circuits this condition may cause high resistance, resulting in intermittent connections.
On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative.
Representative List of Control Modules and Components
The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES
NOT include every possible module or component for every vehicle.
Blower Control Module
Body Control Module (BCM)
Communication Interface Module (CIM)
Cooling Fan Control Module
Electronic Brake Control Module (EBCM)
Electronic Brake and Traction Control Module (EBTCM)
Electronic Suspension Control (ESC) Module
Engine Control Module (ECM)
Heating, Ventilation and Air Conditioning (HVAC) Control Module