B1683 Power Mirror Switch Circuit Fault
Diagnostic trouble code B1683 indicates that the Body Control Module (BCM) or the Door Control Module (DDM/PDM) has detected a fault in the power mirror switch circuit. This typically means the voltage signal from the switch is out of range, or there is an open circuit, short to ground, or short to battery in the switch command lines.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty power mirror switch (internal short or open contacts)
- Damaged wiring in the door or wheel well harness (short to ground or open)
- Corroded, loose, or backed-out terminals in connectors
- Faulty door control module (DDM/PDM) or BCM
- Faulty 5V reference or ground circuit for the switch
3. Symptoms You Will Notice
- Power mirrors do not adjust from the driver or passenger side
- Mirrors may move in only one direction or not at all
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to B1683 for your vehicle.
Inspect the mirror switch and its connector for damage, corrosion, or loose terminals.
Test the switch by measuring voltage and continuity per the wiring diagram.
Check the wiring harness between the switch and door module for opens or shorts.
If wiring and switch are good, test the door module or BCM for proper operation.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is safe to drive. The fault only affects power mirror adjustment, not safety systems.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the switch, wiring, or module needs replacement.