Security system indicator circuit reads low
What it means
B0687. Security system indicator circuit reads low. The body control module cannot light the security indicator and the body warning light comes on.. This Chevy-enhanced code applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.
Findings, check these first
- Faulty instrument panel cluster security indicator driver
- Security indicator circuit shorted to ground
- Corroded or loose instrument panel cluster connector
- Faulty security indicator output in the body control module
- Security indicator pulling low under load
Standard procedure
- Confirm the code with a scan tool
- Inspect the instrument panel cluster and body control module connectors
- Test the security indicator circuit for a short to ground
- Command the security indicator with the scan tool and watch the lamp
- Replace the instrument panel cluster or body control module only after circuit tests pass, then clear the code and retest
Look up another code
Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.
Sources and review
Review: checked against the recorded source material.
- B0687 CHEVROLET Code: Meaning, Causes, and Symptoms | OBD2 Codes - OBD2 Codes
live reference page (obd2-codes.co)
Supports: CHEVROLET and GM-family meaning and likely causes for B0687
Fetched directly. B0687 reads "Security System Indicator Circuit Low".
- Code B0687 meaning and causes | OBDII.pro
live reference page (obdii.pro)
Supports: independent corroboration of the GM meaning
Fetched directly. obdii.pro is a separate publisher and gives the GM meaning as: Security system indicator circuit low More details about the error B0687 and possible reasons for its occurrence.
Last updated 2026-10-10.
Report a correction for B0687. 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.