Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test A : The Defrost System Is Inoperative: Notes
Refer to Heated Window for schematic and connector information.
Normal Operation and Fault Conditions
REFER to: Glass, Frames and Mechanisms - System Operation and Component Description .
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B1C83:12 | Rear Defog Relay: Circuit Short to Battery | This DTC sets when the FCIM detects a short to voltage on the rear window defrost relay control circuit. |
| B1C83:14 | Rear Defog Relay: Circuit Short To Ground or Open | This DTC sets when the FCIM detects an open or short to ground on the rear window defrost relay control circuit. |
Possible Causes
- Fuse
- BJB
- Wiring, terminals or connectors
- Rear window defrost grid
- FCIM
Visual Inspection and Diagnostic Pre-checks
- Verify BJB fuse 99 (40A) is OK.
- Inspect the rear window defrost grid and electrical connectors for damage.
NO RELATED
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.