What Does B2312 Mean?
This code indicates the Body Control Module (BCM) has detected an abnormal signal from the feedback potentiometer that monitors the horizontal position of the passenger side mirror. The potentiometer provides voltage feedback to confirm the mirror glass has moved to the commanded position. The BCM has identified either an open circuit, short circuit, out-of-range voltage, or erratic signal from this position sensor.
Common Causes
45%
Failed or worn feedback potentiometer inside the mirror assembly
30%
Damaged wiring harness or corroded connector between mirror and door/BCM
15%
Loose or corroded ground connection for mirror assembly
10%
Failed Body Control Module (BCM) with faulty mirror control circuit
Diagnostic Steps
1
Step 1: Perform visual inspection of passenger mirror connector at door jamb and mirror base for corrosion, bent pins, water intrusion, or damage. Check door jamb boot for cracks that may allow water entry.
2
Step 2: Using a multimeter, backprobe the feedback potentiometer signal wire at the mirror connector while manually moving the mirror horizontally. Expected reading should be a smooth voltage sweep between approximately 0.5V and 4.5V with no dropouts or spikes.
3
Step 3: Check continuity of all mirror circuit wires from BCM connector to mirror connector with harness wiggle test. Verify ground circuit has less than 0.5 ohms resistance to chassis ground.
4
Step 4: If wiring tests good, measure potentiometer resistance directly at mirror motor terminals (mirror removed from door). Rotate motor manually and verify smooth resistance change typically between 1k-10k ohms with no dead spots.
5
Step 5: If potentiometer is faulty, replace mirror assembly or motor pack (depending on vehicle design). If wiring is faulty, repair harness and apply dielectric grease to connectors.
6
Step 6: Clear codes, operate mirror through full range of motion using switch controls, and verify smooth operation with no code return. Monitor live data for proper feedback voltage sweep.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an abnormal signal from the feedback potentiometer that monitors the horizontal position of the passenger side mirror. The potentiometer provides voltage feedback to confirm the mirror glass has moved to the commanded position. The BCM h...
The most common cause of B2312 (Mirror Passenger Horizontal Feedback Potentiometer Circuit Failure) is: Failed or worn feedback potentiometer inside the mirror assembly
Typical repair costs for B2312 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this only affects mirror adjustment functionality. The mirror will typically remain in its last position but may not adjust electrically. Repair at convenience, though proper mirror adjustment is important for safe visibility.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2312 to identify the root cause.
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Quick Info
Category
Body
System
Body Control System - Power Mirror System
Difficulty
Type
Generic (SAE)
Recommended Tools
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