Incorrect Immobilizer Identifier Received
Table of contents
B3902 GMC Possible Causes
- Faulty Body Control Module (BCM)
- Body Control Module (BCM) harness is open or shorted
- Body Control Module (BCM) circuit poor electrical connection
How do I fix code B3902 GMC?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the B3902 GMC code
The cost of diagnosing the B3902 GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B3902 GMC Description
When certain modules are programmed and configured during installation, the module learns a specific environment identifier which is unique to the vehicle. The environment identifier is used to prevent the swapping modules between vehicles. The Body Control Module (BCM) is the keeper of the environment identifier. The instrument cluster, electronic brake control module, HVAC control module, inflatable restraint sensing and diagnostic module, Engine Control Module (ECM), and steering column lock module (if equipped) each learn the environment identifier during their configuration process. During vehicle operation, the BCM sends the immobilizer identifier as a challenge and each module responds to the challenge by sending the environment identifier back to the BCM. If the BCM sends an incorrect immobilizer identifier or a specific number of incorrect environment identifiers are received, vehicle starting is disabled. The Diagnostic Trouble Code (DTC) sets when the control module’s environment identifier does not match the environment identifier stored by the BCM.