What Does B2338 Mean?
This code indicates the Body Control Module (BCM) has detected an abnormal voltage condition in the mirror switch assembly circuit, specifically a short to battery voltage. This means the circuit is receiving constant battery voltage when it should not, typically caused by damaged wiring or a faulty switch creating an unintended connection to the vehicle's positive power supply. The mirror switch assembly controls the electric adjustment of side mirrors.
Common Causes
40%
Damaged or chafed wiring harness between mirror switch and BCM causing direct contact with battery voltage source
30%
Failed mirror switch assembly with internal short circuit to power
20%
Corroded or damaged connector pins at mirror switch creating cross-circuit with battery feed
10%
Water intrusion or moisture damage in switch assembly causing electrical bridging
Diagnostic Steps
1
Step 1: Perform visual inspection of mirror switch assembly and connector for signs of physical damage, corrosion, water intrusion, or melted plastic. Remove switch from door panel and inspect connector pins for bent, corroded, or crossed terminals.
2
Step 2: Using a digital multimeter, disconnect the mirror switch connector and measure voltage on the BCM side of the harness signal circuits with ignition on. You should see 0V or very low voltage (ground reference). If battery voltage (12-14V) is present, the short is in the harness between BCM and switch.
3
Step 3: Inspect the entire wiring harness from mirror switch through door jamb to BCM for chafing, pinch points, or damage where wires may contact battery voltage sources. Pay special attention to door hinge area and under door trim panels where wires flex during door operation.
4
Step 4: If harness tests good, perform resistance test on mirror switch assembly itself. With switch disconnected and ignition off, check resistance between signal circuits and battery voltage pin. Reading should be infinite (OL). Any continuity indicates internal switch failure.
5
Step 5: Repair or replace identified faulty component (harness section, connector, or switch assembly). Clear codes and verify proper mirror operation in all directions. Retest circuit with multimeter to confirm no voltage present on signal wires with switch in neutral position.
Estimated Repair Cost
$75 - $350
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an abnormal voltage condition in the mirror switch assembly circuit, specifically a short to battery voltage. This means the circuit is receiving constant battery voltage when it should not, typically caused by damaged wiring or a faulty...
The most common cause of B2338 (Mirror Switch Assembly Circuit Short to Battery) is: Damaged or chafed wiring harness between mirror switch and BCM causing direct contact with battery voltage source
Typical repair costs for B2338 range from $75 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this affects only mirror adjustment functionality and does not impact vehicle operation or safety systems. Repair at convenience, though prolonged short circuit conditions could potentially drain battery or cause additional electrical component damage if left unaddressed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2338 to identify the root cause.
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Quick Info
Category
Body
System
Body Electrical System - Mirror Control
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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