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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Isuzu i-370, 2008 Isuzu i-290, 2008 GMC Canyon, and 2008 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Test for less than 1.0 ohm of resistance between the DLC ground circuit terminal 5 and ground.
    • If greater than 1.0 ohm, test the ground circuit for open/high resistance.
    2. IMPORTANT: Cycle the ignition Key OFF before each module disconnect and ON to attempt communication.
  2. Ignition OFF, disconnect the module harness connectors listed one at a time, attempting to communicate with the BCM after each disconnect. Communication should not be available.
    • Digital radio receiver - X1
    • Vehicle communication interface module (VCIM) - X2
    • Transfer case shift control module - X2
    • Instrument panel cluster (IPC) - X1
    • Radio - X1, X2
    • Powertrain control module (PCM) -X1
    • Inflatable restraint sensing and diagnostic module (SDM) - X1
    • Electronic brake control module (EBCM) - X1
    • Generator battery control module - X1
    • If communications are available after a module disconnect, test all the serial data circuits to the last module disconnected for a short to ground or short to voltage. If the circuits test normal, replace the last module disconnected.
  3. Ignition OFF, disconnect the BCM harness connector X1 and X2.
  4. Connect a test lamp between B+ and the following BCM connector terminals. The test lamp should not illuminate.
    • X2, terminal A38
    • X2, terminal A39
    • X2, terminal A44
    • X1, terminal A41
    • X1, terminal A42
    • X1, terminal A47
    • If the test lamp illuminates, test the serial data circuit for a short to ground.
  5. Connect a test lamp between ground and the following BCM connector terminals. The test lamp should not illuminate.
    • X2, terminal A38
    • X2, terminal A39
    • X2, terminal A44
    • X1, terminal A41
    • X1, terminal A42
    • X1, terminal A47
    • If the test lamp illuminates, test the serial data circuit for a short to voltage.
  6. If the circuits test normal, replace the BCM.
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