B1733 — Mirror Driver Vertical Switch Circuit Failure #

Note: The wording of this code may vary by manufacturer (OEM). Below are some known variations by OEM.

• Mirror Driver Vertical Switch Circuit Malfunction (Ford, GM)
• Driver Mirror Up/Down Switch Circuit Error (Chrysler, Dodge)
• Driver Side Mirror Vertical Adjustment Switch Fault (Toyota, Honda)

Summary of DTC B1733 #

The B1733 diagnostic trouble code signals an issue detected in the vertical adjustment circuit of the driver’s side power mirror. This circuit is responsible for sending electrical signals from the mirror adjustment switch to the mirror motor, allowing up and down movement. When the vehicle’s onboard diagnostic system identifies a fault—such as an open, short, or abnormal voltage—in this specific circuit, it triggers the code. While this code does not usually impact driving safety, it may hinder the proper adjustment of the driver’s mirror, affecting visibility and comfort. The code is most commonly found in vehicles equipped with power-adjustable mirrors and sophisticated body control modules.

Common Symptoms for Code B1733 #

When the B1733 code appears, the most frequent symptom is the inability to move the driver’s side mirror vertically. This can be inconvenient for drivers sharing a vehicle or needing to adjust mirrors for better visibility. Some vehicles may display a warning light or message on the dashboard related to mirror adjustment. Less commonly, you might notice erratic or unintended mirror movement.

• Driver’s side mirror won’t move up or down
• Mirror moves only in one direction (up or down, but not both)
• Mirror adjustment switch feels unresponsive or loose
• Intermittent or jerky mirror movement
• Warning light or message about mirror system (if equipped)

Probable Causes for Code B1733 (Ranked by Frequency) #

Understanding the likely root causes can save you time and money. Most issues stem from electrical faults—think of it as a break or interruption in the path that controls mirror movement. Here are the most common culprits, in order of how often they occur:

1. Faulty mirror adjustment switch: The switch may wear out or develop internal electrical faults.
2. Damaged wiring or connectors: Broken wires, loose connectors, or corrosion can disrupt the circuit.
3. Defective mirror motor (vertical actuator): The small motor inside the mirror housing may fail.
4. Body control module (BCM) issues: Rare, but possible—this module manages mirror functions in some vehicles.
5. Blown fuse or relay: If the circuit is fused or relay-controlled, a failure here can cut off power.

Step-by-Step Diagnostic Process for B1733 #

Diagnosing B1733 is a methodical process—think of it as detective work with a multimeter instead of a magnifying glass. Here’s how a professional or experienced DIYer might approach the issue:

• Use an OBD-II scan tool to confirm the presence of B1733 and check for related codes.
• Test the mirror adjustment switch for continuity and proper function using a multimeter.
• Inspect the wiring and connectors between the switch and the mirror for visible damage, corrosion, or disconnections.
• Check the mirror motor (vertical actuator) by applying direct power to see if it responds.
• Examine the relevant fuses and relays associated with the mirror adjustment system.
• If all else seems normal, perform a diagnostic check on the body control module (BCM) for faults or software issues.

Possible Repairs for Code B1733 #

Fixing B1733 depends on pinpointing the faulty component. Start with the most common issues and work your way toward the rarer causes. Here are some proven repair actions:

• Replace the driver’s mirror adjustment switch if it fails continuity tests.
• Repair or replace damaged, corroded, or loose wiring/connectors in the mirror circuit.
• Replace the mirror vertical actuator (motor) if it doesn’t operate with direct power.
• Replace blown fuses or faulty relays in the mirror adjustment circuit.
• If diagnosed, repair or replace the body control module (BCM) (rare).

Is It Safe to Drive with Code B1733? #

Yes, but with limitations. The B1733 code typically does not affect the vehicle’s core safety functions or drivability. However, it can limit your ability to adjust the driver’s mirror for optimal visibility, which is essential for safe lane changes and reversing. If you can manually adjust the mirror or if it’s already in a suitable position, you can continue driving. However, if multiple drivers use the vehicle, or if the mirror is stuck in an unsafe position, prompt repair is recommended.

Vehicles Most Commonly Affected by B1733 #

This code can appear on a wide range of vehicles equipped with power mirrors, but some models are more susceptible due to their electrical design or switch placement. Here are examples of vehicles where B1733 is more frequently reported:

• Ford F-Series trucks (F-150, F-250, etc.)
• Chevrolet Silverado and GMC Sierra
• Chrysler 300, Dodge Charger/Challenger
• Toyota Camry and Corolla (with power mirrors)
• Honda Accord and Civic (select years)
• Jeep Grand Cherokee

Frequent Mistakes & Best Practices for Code B1733 #

Even seasoned technicians can overlook simple fixes or misdiagnose the root cause. Avoiding these pitfalls will save both time and frustration:

• Assuming the motor is faulty without testing the switch and wiring first.
• Overlooking corrosion or loose connections inside the door panel.
• Neglecting to check for blown fuses or faulty relays controlling the mirror circuit.
• Replacing the entire mirror assembly when only the switch or a wire is at fault.
• Not clearing the code after the repair, which can mask a successful fix.

Express FAQ for B1733 #

Here are some quick answers to common questions about B1733:

• Q: Will B1733 cause my power mirrors to stop working completely?
  A: Usually, only the vertical (up/down) adjustment on the driver’s side is affected. Other mirror functions (left/right, heating, folding) typically remain operational.
• Q: Can I fix B1733 myself, or do I need a professional?
  A: If you have basic tools and can safely remove the door panel, you can check for obvious wiring or switch issues. For BCM diagnostics or complex wiring faults, a professional is recommended.