B1743 — Mirror Passenger Vertical Switch Circuit Short To Battery #

The description of DTC B1743 may vary depending on the vehicle manufacturer or Original Equipment Manufacturer (OEM).

• Mirror Passenger Vertical Switch Circuit Short To Battery (Ford, Lincoln, Mercury)
• Door Mirror Vertical Adjustment Switch Circuit High (Mazda)
• Passenger Side Mirror Vertical Motor Switch Short to Power (General Motors – GM)
• Right Mirror Up/Down Switch Circuit Short to Battery (Chrysler, Dodge, Jeep)

Summary of DTC B1743 #

DTC B1743 is a Body (B-series) Diagnostic Trouble Code related to the electrical circuit controlling the vertical adjustment switch of the passenger side mirror. This code indicates that the vehicle’s control module has detected a short to battery (an unintended connection to power) within the vertical switch circuit of the passenger door mirror. In simpler terms, the system senses voltage where it shouldn’t be, signifying possible wiring or switch issues. This fault can prevent the passenger mirror from adjusting vertically and may impact overall mirror function or even trigger other comfort system errors. While not a critical safety code, prompt diagnosis is recommended to restore full mirror operation and prevent further electrical complications.

Frequent Symptoms for DTC B1743 #

When B1743 is stored in your vehicle’s memory, several telltale signs may appear. These symptoms often relate to the passenger side power mirror controls, but sometimes extend to other comfort or door features if the fault disrupts shared circuits. Watch for:

• Passenger side mirror won’t move up or down
• Mirror may move erratically or not respond to commands
• All mirror functions (horizontal and vertical) may be unresponsive
• Clicking or buzzing noise from the mirror switch area
• Blown fuse for power mirrors or other door electronics
• Illuminated “Check Engine” or “Body Control Module” warning, depending on the vehicle

Probable Causes for DTC B1743 #

The most common reasons for B1743 relate to electrical faults in the mirror switch circuit. These range from physical damage to the switch itself, wiring issues, or even a failing control module. Here’s what typically causes this code, from most to least likely:

1. Damaged passenger mirror vertical switch (internal short to power)
2. Shorted or pinched wiring between switch and power source (often in door harness or at the mirror)
3. Moisture intrusion or corrosion at switch connector or wiring plug
4. Faulty passenger mirror motor (vertical adjustment motor shorted internally)
5. Defective Door Module or Body Control Module (BCM) (rare, but possible)

Step-by-Step Diagnosis for DTC B1743 #

Accurate diagnosis of B1743 involves both visual inspection and electrical testing. If you have basic tools and patience, you can pinpoint the cause following these steps:

• Read DTCs with a scan tool and clear the code to see if it returns after activation.
• Inspect the passenger mirror switch and surrounding trim for signs of physical damage or liquid spills.
• Check the wiring harness between the switch and the mirror for pinching, chafing, or exposed conductors.
• Disconnect the mirror switch and test for voltage at the connector with the ignition ON. Excess voltage means a short-to-battery in the harness.
• Test the vertical adjustment motor in the mirror by applying direct power (only if you’re comfortable and have a wiring diagram).
• Reconnect components one at a time to isolate the fault—sometimes the code only reappears when a faulty component is plugged back in.
• Replace or repair the identified faulty component and retest to confirm resolution.

Possible Repairs for DTC B1743 #

Repairing B1743 always depends on the root cause found during diagnosis. Here are the most common fixes, matched to their respective fault:

• Replace the passenger mirror vertical switch if internal electrical failure is found.
• Repair or replace damaged wiring—fix pinched, cut, or corroded wires in the door harness.
• Clean or replace corroded connectors at the switch or mirror plug.
• Replace the passenger mirror assembly if the vertical adjustment motor is shorted.
• Replace the Door Module or Body Control Module only if all other possibilities are eliminated and module failure is confirmed.

Is It Safe to Drive with Code B1743? #

Yes, but with limitations. While B1743 will not affect your engine performance or primary safety systems, driving with this code means you may lose the ability to adjust the passenger side mirror vertically. This can reduce visibility and comfort, especially if more than one driver uses the vehicle. If the code causes fuses to blow repeatedly, other systems may also be affected. It’s best to address the issue soon, but your car remains safe to drive in most situations.

Vehicles Most Affected by DTC B1743 #

B1743 appears more frequently on certain makes and models, especially those with advanced mirror adjustment systems. Modern vehicles from these manufacturers are commonly affected:

• Ford (F-150, Explorer, Expedition)
• Lincoln (MKZ, Navigator)
• Mazda (Mazda6, CX-5, CX-9)
• General Motors (Chevrolet Malibu, GMC Sierra, Cadillac CTS)
• Chrysler, Dodge, Jeep (Grand Cherokee, 300, Charger)

Common Mistakes & Best Practices for DTC B1743 #

It’s easy to chase your tail with electrical mirror faults. Avoid these pitfalls and follow these tips for a smoother repair:

• Don’t replace the mirror assembly or module without confirming the fault—test the switch and wiring first.
• Always check for moisture or spilled drinks near the switch, especially if the issue appeared after cleaning or a rainy day.
• Use the correct wiring diagram for your specific vehicle and model year.
• Don’t ignore signs of other electrical faults—multiple codes may mean a shared harness or ground issue.
• Clear codes after every repair and test the system thoroughly before reassembling the door.

Express FAQ for DTC B1743 #

Here are quick answers to common questions about B1743:

• Q: Can B1743 cause battery drain?
  A: Rarely, but a constant short to battery may keep the circuit energized, which can cause slow battery drain if left unresolved.
• Q: Will replacing the fuse fix B1743?
  A: No, replacing the fuse only treats the symptom. The underlying short or faulty switch must be repaired for a lasting solution.