B1423 — Power Window RR Motor Circuit Open #

Note: The code description may vary depending on the vehicle manufacturer (OEM). Always refer to your specific service manual for the most accurate terminology.

• B1423 – Rear Right Power Window Motor Circuit Open (Toyota, Lexus)
• B1423 – RR Window Motor Circuit/Open (Hyundai, Kia)
• B1423 – Power Window Motor Circuit Open (Right Rear) (Mazda)

Summary of code B1423 #

The B1423 diagnostic trouble code (DTC) indicates an open circuit in the rear right (RR) power window motor circuit. Simply put, the vehicle’s onboard computer (often called the Body Control Module or BCM) has detected a disruption in the electrical pathway that controls the rear right power window. This interruption prevents the window from operating as intended. Open circuits can result from broken wires, faulty connectors, or a failed window motor. This code is most commonly seen when attempting to operate the right rear window and it fails to move. Diagnosing and repairing this fault ensures both convenience and safety for all occupants.

Common symptoms for code B1423 #

When B1423 is present, you’ll likely notice issues specifically with the rear right power window. These symptoms can range from subtle to obvious, but they usually affect the window’s ability to open or close. Here’s what you might experience:

• The rear right window does not respond to switch inputs.
• Window moves intermittently or only in one direction (up or down).
• No sound or movement from the rear right window motor when the switch is pressed.
• Other windows operate normally.
• Possible illumination of the check engine or body warning light (varies by OEM).

Most likely causes of code B1423 #

B1423 is usually triggered by a few recurring issues. Understanding the most probable causes helps technicians (and car owners) prioritize the diagnostic process and avoid chasing red herrings. From most to least frequent, here are the usual suspects:

1. Faulty rear right power window motor (worn brushes, failed windings, or internal open circuit).
2. Open or broken wiring between the switch, BCM, and window motor (often at door harness flex points).
3. Corroded or loose connectors at the window motor or door module.
4. Defective power window switch (either at the driver’s master switch or rear passenger door).
5. Fault in the Body Control Module (BCM) (rare, but possible).

Step-by-step diagnosis for code B1423 #

Proper diagnosis follows a logical process. Skipping steps can lead to unnecessary parts replacement or missed issues. Here’s a proven, step-by-step approach for B1423:

• Verify the complaint: Attempt to operate the rear right window from both the main (driver) switch and the rear door switch.
• Check for related DTCs: Scan for additional codes that might indicate network or switch faults.
• Inspect fuses and relays: Confirm the window fuse and any associated relay are intact and functioning.
• Perform a visual inspection: Examine the wiring harness for visible damage, especially where the door harness flexes.
• Test for power and ground: With a digital multimeter, check for voltage and ground at the window motor connector while operating the switch.
• Check continuity: If no voltage, test continuity of wiring between the switch, motor, and BCM.
• Test the window motor: Apply direct battery power and ground to the motor to see if it operates.
• Inspect connectors for corrosion: Look for greenish deposits or bent pins at all relevant connectors.
• Evaluate switch operation: Test the switch with an ohmmeter or swap with a known good unit if possible.
• Assess BCM function: If all else checks out, consult OEM flowcharts for BCM testing or reprogramming.

Possible repairs for code B1423 #

Repairing B1423 means addressing the root cause found during diagnosis. Here are the most common solutions, each paired with its associated fault:

• Replace the rear right power window motor if internal failure or open circuit is confirmed.
• Repair or replace damaged wiring in the door harness or between connectors.
• Clean or replace corroded connectors at the motor, switch, or BCM.
• Replace the power window switch (main or rear) if found defective.
• Replace or reprogram the BCM only if all other components test good and the issue persists.

Is it safe to drive with code B1423? #

Yes, but with limitations. Code B1423 does not affect the drivability or safety fundamentals of your vehicle. However, you will lose the ability to open or close the rear right window. This can impact passenger comfort, ventilation, and—on some vehicles—rear occupant egress in an emergency. If you frequently transport passengers or need all windows functional, address this code promptly.

Vehicles most commonly affected by code B1423 #

This code is most frequently reported on certain Asian-made vehicles but can be found across many brands using similar power window control strategies. Models where B1423 is often encountered include:

• Toyota Camry, Corolla, RAV4, Highlander
• Lexus ES, RX, GX
• Hyundai Sonata, Elantra, Santa Fe
• Kia Optima, Sorento, Forte
• Mazda 3, 6, CX-5

Common mistakes & best practices with code B1423 #

Even experienced technicians can fall into certain traps with B1423. Here’s how to avoid the most frequent pitfalls and ensure a successful repair:

• Don’t immediately replace the window motor without testing power, ground, and switch operation first.
• Always inspect the wiring harness at door flex points—broken wires here are a leading cause.
• Check connector integrity for corrosion or poor fit before assuming component failure.
• Use OEM or high-quality aftermarket parts for reliable repairs, especially window motors and switches.
• Clear the code and retest after repairs to confirm the issue is resolved.

Quick FAQ for code B1423 #

Here are answers to some of the most common questions about B1423:

• Q: Will B1423 cause other windows to stop working?
  A: No, this code is specific to the rear right window. Other windows should operate normally unless there are additional faults.
• Q: Can a blown fuse cause B1423?
  A: Yes, if the fuse protecting the rear right window circuit is blown, the code may set. Always check fuses during diagnosis.
• Q: Do I need to visit the dealer to clear B1423?
  A: Not necessarily. Most OBD-II/EOBD scan tools can clear this code after repair, but if the fault persists, OEM-specific diagnostics may be required.