What Does B1743 Mean?
This code indicates the Body Control Module (BCM) has detected an abnormal voltage condition in the passenger side mirror vertical adjustment switch circuit. Specifically, the circuit is experiencing a short to battery voltage, meaning unwanted battery power is present on the switch control circuit when it should not be. This prevents proper operation of the passenger mirror's up/down adjustment function.
Common Causes
45%
Damaged or chafed wiring harness in door jamb or mirror assembly causing short to power wire
30%
Faulty passenger mirror switch assembly with internal short to power
15%
Water intrusion or corrosion in mirror switch connector causing cross-circuit short
10%
Failed Body Control Module with internal circuit fault
Diagnostic Steps
1
Step 1: Perform visual inspection of passenger door jamb wiring harness and mirror assembly wiring for visible damage, chafing, or pinched wires. Look for wire insulation wear where harness flexes during door operation.
2
Step 2: Disconnect the passenger mirror switch connector and measure voltage at the vertical switch circuit terminal (BCM side) using a multimeter. Should read 0V with ignition on; battery voltage present confirms wiring short, no voltage indicates switch internal fault.
3
Step 3: If wiring shows battery voltage, disconnect door harness connector at body and check for voltage again. Voltage gone indicates short in door harness; voltage still present indicates short between BCM and body connector.
4
Step 4: Inspect mirror switch assembly connector terminals for corrosion, moisture, or pushed-out pins causing terminal-to-terminal contact. Clean and reseat connector, checking for proper terminal retention.
5
Step 5: If wiring and connectors test good, test mirror switch assembly by connecting it to known good power/ground circuit and verifying proper resistance changes when operating vertical adjustment. Replace switch if faulty.
6
Step 6: Clear codes, reconnect all components, and verify mirror operation functions properly in all directions. Re-scan for codes to confirm repair resolved the short-to-battery condition.
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an abnormal voltage condition in the passenger side mirror vertical adjustment switch circuit. Specifically, the circuit is experiencing a short to battery voltage, meaning unwanted battery power is present on the switch control circuit ...
The most common cause of B1743 (Mirror Passenger Vertical Switch Circuit Short To Battery) is: Damaged or chafed wiring harness in door jamb or mirror assembly causing short to power wire
Typical repair costs for B1743 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this affects only passenger mirror adjustment functionality and does not impact vehicle safety systems or operation. Repair at convenience, though prolonged short condition could potentially drain battery or damage BCM circuits if severe.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1743 to identify the root cause.
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Quick Info
Category
Body
System
Power Mirror Control System
Difficulty
Type
Manufacturer
Recommended Tools
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