2008 Chevrolet Chevy Express G3500, Van Passenger ExtendedFACTORY OEM SERVICE PROCEDURE

Control Units

CONTROL UNITS LOCATION

Component Location
Body Control Module (BCM) Behind lower right side of dash. See Figure.
Central Sequential Fuel Injection (Central SFI) Connector (4.3L) (1) At top of engine. See Figure.
Coolant Heater Control (1) On coolant heater assembly. See Figure.
Cruise Control Module (CCM) Near brake fluid reservoir. See Figure.
Electronic Brake Control Module (EBCM) On left frame rail, near center of vehicle.
Electronic Control Module (ECM) Left side of engine compartment. See Figure.
Fuel Pump Flow Control Module (5.3L) At rear of vehicle, attached to left rear frame rail.
Glow Plug Control Module (GPCM) (6.6L Turbo) (5) Left rear of engine. See Figure.
Glow Plug Control Module (GPCM) (6.6L) (5) Top rear of engine. See Figure.
HVAC Control Processor - Auxiliary Center front of headliner. See Figure.
Ignition Coil/Module 1 Connector (4.8L, 5.3L & 6.0L) (13) At top left of engine. See Figure.
Ignition Coil/Module 2 Connector (4.8L, 5.3L & 6.0L) (5) At top right of engine. See Figure.
Ignition Coil/Module 3 Connector (4.8L, 5.3L & 6.0L) (11) At top left of engine. See Figure.
Ignition Coil/Module 4 Connector (4.8L, 5.3L & 6.0L) (6) At top right of engine. See Figure.
Ignition Coil/Module 5 Connector (4.8L, 5.3L & 6.0L) (9) At top left of engine. See Figure.
Ignition Coil/Module 6 Connector (4.8L, 5.3L & 6.0L) (7) At top right of engine. See Figure.
Ignition Coil/Module 7 Connector (4.8L, 5.3L & 6.0L) (8) At top left of engine. See Figure.
Ignition Coil/Module 8 Connector (4.8L, 5.3L & 6.0L) (9) At top right of engine. See Figure.
Ignition Control Module (ICM) Connector (3) On top right side of engine, at ignition coil. See Figure.
Inflatable Restraint I/P Module Behind right side of dash. See Figure.
Inflatable Restraint I/P Module Connector (2) Behind right side of dash. See Figure.
Inflatable Restraint Roof Rail Module - Left Front Left side of headliner.
Inflatable Restraint Sensing & Diagnostic Module (SDM) Under left front seat. See Figure.
Inflatable Restraint Sensing & Diagnostic Module (SDM) Connector (13) Under left front seat. See Figure.
Intake Air Heater (IAH) Module (13) Between the intake manifold tube and the air cooler outlet duct. See Figure.
Powertrain Control Module (PCM) (3) In engine compartment, on left inner fender. See Figure.
Theft Deterrent Module (TDM) In steering column, near ignition key cylinder housing.
Throttle Actuator Control (TAC) Module At left rear of engine compartment. See Figure.
Transmission Control Module (TCM) (AWD) Right front corner of engine compartment, near battery.
Transmission Control Module (TCM) (6.6L) Left front corner of engine compartment. See Figure.
Turn Signal/Hazard Flasher Module Behind left center of dash. See Figure.
Vehicle Communication Interface Module (VICM) (8) Below steering column. See Figure.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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