Passenger Mirror Horizontal Adjustment Switch Open Circuit
The B1746 code indicates that the Body Control Module (BCM) or passenger door module has detected an open circuit in the passenger side exterior mirror horizontal adjustment switch. This prevents the system from receiving the left/right movement request signal from the driver or passenger door switch, so the mirror cannot be adjusted horizontally.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty passenger mirror switch with internal open circuit
- Damaged wiring or disconnected connector between the switch and the BCM/door module
- Failed Body Control Module (BCM) or door module
- Corroded or dirty contacts in the switch or mirror connector
3. Symptoms You Will Notice
- Passenger side mirror does not move left or right
- Mirror adjustment switch may feel loose or unresponsive
4. Step-by-Step Diagnosis
Inspect the passenger mirror switch and connector for corrosion, damage, or loose pins
Check wiring continuity between the switch and the BCM/door module
Test the switch operation with a multimeter to verify internal open circuit
If wiring and switch are good, suspect a faulty BCM or door module
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is safe to drive. The issue only affects the horizontal adjustment of the passenger mirror, which is a convenience feature and does not impact vehicle safety.
How much does it cost to fix?▼
Repair costs typically range from $50 to $200 for a switch replacement, or $200 to $600 if the BCM or door module needs replacement, including labor.