B1745 — Mirror Passenger Horizontal Switch Circuit Failure #

Note: The code description may vary depending on the vehicle manufacturer.

• B1745: Passenger Side Mirror Horizontal Switch Circuit Malfunction (Ford, GM, Chrysler)
• B1745: Power Mirror Horizontal Motor Switch Circuit Failure (Toyota)
• B1745: Right Mirror Horizontal Adjustment Switch Circuit Failure (Honda, Nissan)

Code Summary for B1745 #

The B1745 diagnostic trouble code (DTC) indicates a fault detected in the electrical circuit responsible for the horizontal adjustment switch of the passenger (right) side mirror. When your vehicle’s electronic control unit (ECU) or body control module (BCM) senses a malfunction—such as an open, shorted, or high resistance circuit—it triggers this code and may illuminate a warning light. This circuit connects the mirror adjustment switch to the mirror motor, allowing you to move the passenger side mirror left and right. A failure here typically means the horizontal movement is impaired or nonfunctional. While not a mission-critical issue, this code can impact safety and comfort, especially during lane changes or parking.

Common Symptoms for Code B1745 #

You might notice several signs if your vehicle is experiencing a B1745 code. Most notably, the passenger side mirror may refuse to move horizontally when you use the adjustment switch. Sometimes, the mirror may only move in one direction or not at all. In rare cases, other mirror functions—such as heating or vertical movement—may also be affected if they share wiring or components. Here are typical symptoms:

• Passenger side mirror does not move left or right
• Mirror only moves in one horizontal direction
• No response from the mirror adjustment switch for the right side
• Unusual noises or clicking from inside the mirror housing
• Mirror may move intermittently or erratically
• Other mirror functions (heating, vertical adjustment) sometimes affected

Probable Causes for Code B1745 #

Several issues can lead to a B1745 code, most linked to the switch circuit’s integrity or the components it controls. Understanding the most common culprits helps target your diagnosis efficiently. Here are the most frequent causes, in order of likelihood:

1. Faulty passenger mirror horizontal adjustment switch
2. Open or shorted wiring in the mirror switch circuit
3. Loose, corroded, or damaged connector at the mirror or switch
4. Defective passenger side mirror motor
5. Body Control Module (BCM) or ECU issue (rare)
6. Physical damage to the mirror assembly or water intrusion

Step-by-Step Diagnosis for Code B1745 #

Diagnosing a B1745 code involves a systematic approach to isolate the fault. Always start with the basics and move on to more involved checks only if necessary. Here’s a typical diagnostic workflow:

• 1. Scan for additional DTCs: Use an OBD-II scanner to check if other codes are present, which may indicate related problems.
• 2. Inspect the mirror switch and controls: Visually examine and test the mirror adjustment switch for obvious signs of failure or stickiness.
• 3. Check the passenger mirror movement: Confirm if the mirror moves vertically but not horizontally to help narrow down the fault to the horizontal circuit.
• 4. Inspect wiring and connectors: Examine the wiring harness and connectors between the switch, BCM, and mirror for corrosion, loose pins, or damage.
• 5. Test the mirror motor: Apply direct battery voltage to the horizontal motor pins (as per OEM wiring diagram) to see if the motor responds.
• 6. Check circuit continuity: Use a multimeter to check for open circuits, shorts, or excessive resistance in the wiring.
• 7. Evaluate the BCM/ECU: If all other components check out, the control module may have an internal fault—consult OEM service information for further testing.

Possible Repairs for Code B1745 #

Repairing a B1745 code depends on what you find during diagnosis. Always address wiring and connectors before replacing expensive components. Here are the most common solutions:

• Replace the mirror horizontal adjustment switch if it fails function or continuity tests
• Repair or replace damaged, corroded, or shorted wiring in the circuit
• Clean and secure all connectors related to the mirror and switch
• Replace the passenger side mirror motor if it doesn’t respond to direct voltage
• Replace the entire mirror assembly if physical damage or water intrusion is evident
• Rarely, reprogram or replace the BCM/ECU as per OEM guidelines

Is It Safe to Drive with Code B1745? #

Yes, you can drive with a B1745 code, but with limitations. While this fault won’t affect critical driving functions, it does compromise your ability to adjust the passenger mirror for optimal visibility. This can increase blind spots and make lane changes or parking riskier, especially if multiple drivers use the vehicle. For safety and convenience, address the issue promptly.

Vehicles Most Commonly Affected by Code B1745 #

This code is most frequently found on vehicles with power mirrors and electronic adjustment switches, especially mid-2000s to present-day models. Certain makes and models see this issue more often due to switch design or wiring routing:

• Ford F-150, Explorer, Edge
• Chevrolet Silverado, Malibu, Equinox
• Chrysler 300, Dodge Charger, Jeep Grand Cherokee
• Toyota Camry, Corolla, Highlander
• Honda Accord, CR-V, Civic
• Nissan Altima, Rogue, Sentra

Common Mistakes & Best Practices for Code B1745 #

Even seasoned technicians can fall into common traps with this DTC. Avoiding these errors saves time and money:

• Replacing the mirror motor or assembly without checking the switch or wiring first
• Overlooking corroded or loose connectors, especially after water intrusion or repairs
• Not verifying the issue with a multimeter or scan tool before swapping parts
• Ignoring TSBs (Technical Service Bulletins) from the OEM for known switch or wiring defects
• Using non-OEM components that may not match the original circuit specifications

Express FAQ — B1745 Mirror Passenger Horizontal Switch Circuit Failure #

Still have questions? Here are quick answers to common concerns:

• Q: Can a B1745 code drain my battery?
  A: Very unlikely. Unless the circuit is shorted and causing the mirror motor to run continuously (rare), this code does not typically cause battery drain.
• Q: Will resetting the code fix the mirror?
  A: No. Clearing the code with a scan tool will remove the warning temporarily, but the code will return unless the underlying electrical fault is repaired.
• Q: Is this a DIY repair?
  A: Checking connectors and simple wiring is possible for an experienced DIYer, but deeper diagnostics or part replacement may require professional tools and knowledge.