B1789 Code - Mirror Passenger Down Circuit Short To Ground
Quick Answer
The Body Control Module (BCM) monitors the Mirror Passenger Down Motor. Common causes include Faulty Mirror Passenger Down Motor, Mirror Passenger Down Motor harness is open or shorted, Mirror Passenger Down Motor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- B1789 indicates Mirror Passenger Down Circuit Short To Ground.
- Common causes
- Common causes include Faulty Mirror Passenger Down Motor, Mirror Passenger Down Motor harness is open or shorted, Mirror Passenger Down Motor circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code B1789 Description
What are the Possible Causes of the DTC B1789?
- Faulty Mirror Passenger Down Motor
- Mirror Passenger Down Motor harness is open or shorted
- Mirror Passenger Down Motor circuit poor electrical connection
- Faulty Body Control Module (BCM)
How to Fix the DTC B1789?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the B1789 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about B1789 Code
1. What does the OBDII code B1789 mean?
B1789 indicates a short to ground in the passenger mirror down circuit, which affects the functionality of the mirror's vertical adjustment.
2. What are the common symptoms of the B1789 code?
Symptoms include the passenger-side mirror not moving downward, limited adjustability, or no response when using the mirror control switch.
3. What causes the B1789 code to appear?
The code is typically caused by damaged wiring, a short to ground in the mirror circuit, a faulty mirror motor, or a malfunctioning mirror control switch.
4. How can I diagnose the B1789 code?
Start by inspecting the passenger mirror wiring for damage or exposed wires, test the mirror motor for proper operation, and check the mirror control switch for continuity.
5. Can a faulty mirror motor trigger the B1789 code?
Yes, a defective passenger-side mirror motor can create a short to ground, leading to this code.
6. Is the B1789 code critical to address immediately?
While it won’t affect vehicle safety or drivability, it’s best to repair it promptly to restore full functionality to the passenger-side mirror.
7. How do I fix the B1789 code?
Repairs may include replacing damaged wiring, repairing the ground connection, replacing the mirror motor, or replacing the mirror control switch.
8. Can clearing the B1789 code fix the issue?
Clearing the code without addressing the root cause will likely result in the code returning, as the underlying problem still exists.
9. What tools are needed to repair the B1789 code?
You’ll typically need a multimeter for electrical testing, wiring repair tools, and potentially a replacement mirror motor or control switch.
10. Can the B1789 code be caused by a blown fuse?
While uncommon, a blown fuse in the mirror control circuit could contribute to electrical issues, so checking fuses is a good step in the diagnostic process.
Discuss the causes and fixes for B1789 OBDII Code
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