B3031
Security System Controller in Learn Mode
What it means
B3031. Security System Controller in Learn Mode. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Impala, Colorado.
Findings, check these first
- Interrupted Passlock sensor relearn procedure
- Replaced BCM or PCM without completing the relearn
- Low battery voltage during programming
- Faulty Passlock sensor in the ignition lock housing
- Worn ignition cylinder preventing a stable sensor signal
Standard procedure
- Complete the full 30-minute GM security relearn procedure
- Connect a battery maintainer so voltage stays stable during relearn
- Verify the Passlock sensor signal with a scan tool
- Inspect the ignition cylinder for excessive play
- Replace the Passlock sensor only if the relearn will not complete
Look up another code
Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.
Sources and review
Review: no source links are recorded for this entry.
Last updated 2026-09-25.
Report a correction for B3031. Include your vehicle, the issue and a source if you have one.
This fault sits in the GM theft deterrent system. The GM security codes and Passlock relearn guide covers the families and the relearn cycles.