Diagnostic Aids
WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
- When the instrument cluster detects low voltage at the ignition 1 voltage circuit, the instrument cluster will not communicate with the scan tool, and the odometer and PRNDL displays will not be illuminated. The season odometer will display if the trip reset switch is pressed, and the instrument cluster will communicate with the scan tool until the trip reset switch is released.
- An intermittent condition is likely to be caused by an open condition in the ignition 1 voltage circuit.
- DTC B1372 can only be read by the scan tool as a history code once the fault is removed. Refer to Scan Tool Does Not Communicate with Class 2 Device for diagnosis of a loss of communication with the instrument cluster.