C0023

Code

Generic C — Chassis

Stop Lamp Control

Brand: Generic

Type: C — Chassis

Views: UK: 37 EN: 80 RU: 50

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Page language: EN

Blown fuse for stop/taillight circuit
Failed brake (stop) light bulbs
Faulty brake light (stop lamp) switch at the pedal
Damaged wiring or connector (open, short to ground, short to battery) in stop lamp circuit
Corroded or poor ground at lamp or BCM
Faulty Body Control Module (BCM) or stop-lamp relay

Scan for stored and pending codes and note freeze-frame data
Visually inspect rear bulbs and sockets for damage or corrosion; replace bulbs to test
Check fuse(s) for the stop/taillight circuit
Operate brake pedal and observe lamp behavior while an assistant watches the lamps
Back-probe brake light switch connector and measure voltage/continuity with pedal released and pressed
Inspect wiring at rear harness, trunk hinge, lamp sockets and grounds for chafing/shorts/water intrusion

Battery voltage at stop lamp fuse: nominal 11–14.5 V (vehicle running or key on)
Lamp socket voltage when switch closed (brake pedal pressed): ~12 V (or ground returned to 0 V on ground-switched systems)
Brake switch continuity: open with pedal released, closed when pressed (or changes between reference voltage and ground on electronic switches)
Typical bulb filament resistance (12 V bulbs): low ohms (varies by lamp wattage) — expect continuity, not infinite resistance

Retrieve all codes and freeze-frame info using a scan tool; clear and re-check to confirm repeatability.
Visually inspect and test bulbs and sockets; replace suspect bulbs and retest operation.
Check fuse(s) related to stop/taillight; replace if blown and retest. If fuse blows again, suspect short to power.
Back-probe lamp socket with multimeter while operating brake pedal; verify expected voltage (or ground) at each rear lamp circuit.
Test brake light switch: verify continuity or proper signal change as pedal is pressed; replace switch if out of spec.
Inspect and test ground at lamp assembly and common chassis grounds; clean and tighten as needed.
Follow wiring harness from lamp to connector/BCM looking for damaged insulation, pin corrosion, or water damage; repair wiring or connector faults.
If lamps still fail with correct voltage to socket, remove and bench-test lamp holder and circuit; repair or replace as needed.
If wiring and components OK, check BCM inputs/outputs and for communication errors; test BCM power/ground and harness connectors. Reprogram or replace BCM only after isolating fault to module.
After repair, clear codes and verify proper operation over road test/cycle and re-scan for reappearance.