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Home >> Chevrolet >> 2012 >> Volt >> Repair and Diagnosis >> External Pages >> Different car >> Section 78 (Immobilizer System) >> Diagnostic Information and Procedures >> DTC B2955 >> Circuit/System Testing
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Circuit/System Testing

WARNING: This page is about a different car, the 2011 Chevrolet Volt. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the K89 immobilizer control module.
  2. Ignition OFF, test for less than 30 Ω between the low reference circuit terminal 1 and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K9 BCM.
  3. Connect a test lamp between the B+ circuit terminal 3 and ground.
  4. While observing the test lamp, turn the ignition ON. The test lamp should illuminate for three seconds.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
  5. Test for 12-13 V between the serial data circuit terminal 2 and ground.
    • If less than the specified range, test the serial data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
    • If greater than the specified range, test the serial data circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
  6. If all circuits test normal, replace the K89 immobilizer control module. Verify DTC B2955 is not set.
    • If the DTC is set, replace the K9 BCM.
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