What Does C1743 Mean?
The rear parking sounder circuit is shorted to battery voltage. This means the sounder's control wire is making unwanted contact with a 12V source, which may cause the sounder to buzz continuously, remain silent, or operate erratically. The parking assist module detects the abnormal voltage on the circuit and sets this fault code.
Common Causes
35%
Wiring harness damage with the sounder control wire touching a 12V power wire
25%
Failed rear sounder with internal short to power supply rail
20%
Corroded or water-damaged connector at the sounder causing cross-pin contact
15%
Pinched or chafed wiring during previous trunk/bumper work or cargo loading
5%
Parking assist module internal fault on the sounder output circuit
Diagnostic Steps
1
Disconnect the rear sounder connector and measure voltage on the control wire from the module side — with the sounder disconnected and the system not actively commanding it, there should be 0V. Battery voltage present indicates a harness short.
2
Inspect the sounder connector for corrosion, moisture damage, or bent pins that could bridge to an adjacent power pin.
3
Check the sounder's internal resistance and verify no low-resistance path exists between its terminals and any power supply — a short indicates a failed sounder unit.
4
Trace the sounder wiring, particularly where it routes through the trunk area, behind rear bumper trim, and through any body panel grommets — look for pinched or chafed insulation.
5
If the harness is clean and the sounder tests good, check the module's output by monitoring the sounder pin with a lab scope while commanding the system on and off.
Estimated Repair Cost
$40 - $250
Parts + labor, varies by vehicle and location
The rear parking sounder circuit is shorted to battery voltage. This means the sounder's control wire is making unwanted contact with a 12V source, which may cause the sounder to buzz continuously, remain silent, or operate erratically. The parking assist module detects the abnormal voltage on the c...
The most common cause of C1743 (Rear Sounder Circuit Short to Vbatt) is: Wiring harness damage with the sounder control wire touching a 12V power wire
Typical repair costs for C1743 range from $40 to $250, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle is safe to drive. The rear parking sounder may buzz constantly (annoying but not dangerous) or not work at all. If the sounder is buzzing continuously, it can be distracting. Use mirrors and cameras when reversing. This is a convenience feature fault with no impact on driving safety.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1743 to identify the root cause.
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Quick Info
Category
Chassis
System
Parking Assist System
Difficulty
Type
Manufacturer
Recommended Tools
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