What Does B2346 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the positive reference voltage supply circuit for the mirror switch assembly. The BCM supplies a reference voltage (typically 5V) to the mirror switch to monitor driver inputs for mirror position adjustment. An open circuit means the voltage path is interrupted, preventing the BCM from communicating with or powering the mirror switch properly.
Common Causes
40%
Open circuit or break in the reference voltage wire between BCM and mirror switch
30%
Corroded, loose, or damaged connector at mirror switch or BCM
20%
Failed mirror switch assembly with internal open circuit
10%
BCM internal fault preventing reference voltage output
Diagnostic Steps
1
Step 1: Visually inspect the mirror switch connector and BCM connector for corrosion, bent pins, pushed-out terminals, or moisture intrusion. Check connector locking mechanisms for proper engagement.
2
Step 2: Using a digital multimeter, backprobe the mirror switch connector reference voltage pin (consult wiring diagram for specific pin) with key on, engine off. Verify presence of reference voltage (typically 5V). If voltage is absent, proceed to BCM connector.
3
Step 3: Disconnect mirror switch connector and BCM connector. Using multimeter in ohms mode, test continuity of the reference voltage wire from BCM harness side to mirror switch harness side. Reading should be less than 1 ohm. Infinite resistance confirms open circuit in wiring.
4
Step 4: If wiring shows continuity, reconnect BCM and measure reference voltage output directly at BCM connector with mirror switch disconnected. If voltage is present at BCM but not at switch, repair open in harness. If no voltage at BCM, replace BCM.
5
Step 5: If voltage reaches mirror switch and wiring is intact, substitute with known-good mirror switch to verify internal switch failure. Clear codes and verify repair by cycling mirror functions and confirming no code return.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an open circuit in the positive reference voltage supply circuit for the mirror switch assembly. The BCM supplies a reference voltage (typically 5V) to the mirror switch to monitor driver inputs for mirror position adjustment. An open ci...
The most common cause of B2346 (Mirror Switch Reference Voltage Positive Common Open Circuit) is: Open circuit or break in the reference voltage wire between BCM and mirror switch
Typical repair costs for B2346 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving. This code only affects power mirror adjustment functionality and does not impact vehicle safety systems or driveability. Repair at convenience, though proper mirror adjustment is important for visibility and safe lane changes.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2346 to identify the root cause.
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Quick Info
Category
Body
System
Body Controls and Accessories
Difficulty
Type
Generic (SAE)
Recommended Tools
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