B154B Code - Passenger Mirror Internal Malfunction
Quick Answer
The outside mirror switch and passenger window switch are on a serial data circuit with the memory seat module as the master. Common causes include Faulty Passenger Outside Rearview Mirror Motor, Passenger Outside Rearview Mirror Motor harness is open or shorted, Passenger Outside Rearview Mirror 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
- B154B indicates Passenger Mirror Internal Malfunction.
- Common causes
- Common causes include Faulty Passenger Outside Rearview Mirror Motor, Passenger Outside Rearview Mirror Motor harness is open or shorted, Passenger Outside Rearview Mirror 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 B154B Description
Mirror position is determined by both horizontal and vertical position sensors in each of the power mirrors. The outside mirror switch and passenger window switch supply a 5 V reference, low reference, and horizontal and vertical position signal circuits to these sensors. The signal circuits are referenced from 5 V by the switches and the signal circuit voltage levels represent the mirror positions. The mirror positions are sent to the memory seat module through the serial data circuit where they are stored for memory mirror operation. When the memory seat module receives a memory recall command, the memory seat module will send the go to position commands to the outside mirror switch and passenger window switch. The switches will then drive the appropriate mirror motors to the commanded position sensor settings.
The Diagnostic Trouble Code (DTC) will be set when an internal malfunction has been detected by the passenger window switch while commanding the passenger outside rearview mirror UP, DOWN, LEFT, or RIGHT.
What are the Possible Causes of the DTC B154B?
- Faulty Passenger Outside Rearview Mirror Motor
- Passenger Outside Rearview Mirror Motor harness is open or shorted
- Passenger Outside Rearview Mirror Motor circuit poor electrical connection
How to Fix the DTC B154B?
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 B154B 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.
Need more information about the B154B code?
Need more information on how to fix the B154B code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the B154B code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- B154B Buick — Passenger Mirror Internal Malfunction
- B154B Cadillac — Passenger Mirror Internal Malfunction
- B154B Chevrolet — Passenger Mirror Internal Malfunction
- B154B GMC — Passenger Mirror Internal Malfunction
Frequently Asked Questions about B154B Code
1. What does the OBDII code B154B mean?
Code B154B indicates an internal malfunction in the passenger side mirror assembly, often related to its electronic components or motor.
2. What are the common symptoms of code B154B?
Symptoms include the passenger mirror not adjusting, folding, or heating properly, and possible loss of control from the mirror adjustment switch.
3. What causes the B154B code to appear?
Common causes include a faulty mirror motor, damaged wiring or connectors, or internal failure of the mirror control module.
4. Can I still drive my vehicle with the B154B code?
Yes, the vehicle is typically safe to drive, but the passenger mirror may not function correctly, which can affect visibility and safety.
5. How do I diagnose the B154B code?
Start by inspecting the wiring and connectors to the passenger mirror for damage or disconnections, and test the mirror motor and module functionality.
6. What tools are needed to troubleshoot the B154B code?
An OBDII scanner and a multimeter are helpful for diagnosing this code, along with basic tools for accessing and inspecting the mirror assembly.
7. How can I fix the B154B code?
Repairs may involve replacing the passenger mirror assembly, repairing damaged wiring, or replacing the mirror control module.
8. How much does it cost to fix a B154B code?
Repair costs vary depending on whether the mirror assembly, wiring, or module needs replacement, typically ranging from $150 to $500.
9. Can a B154B code be cleared without repairs?
Clearing the code without addressing the root cause may temporarily remove it, but the issue will likely return.
10. Does the B154B code indicate a problem with the driver-side mirror?
No, the B154B code specifically refers to the passenger side mirror, not the driver's side.
Discuss the causes and fixes for B154B OBDII Code
Code B154B comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
