B1D33

Symptoms

• The driver's mirror does not heat up when the heating function is turned on
• The malfunction indicator light or error code B1D33 is on on the dashboard
• Fogging or icing of the driver's mirror
• No response when pressing the heating control button

Causes

• Broken or damaged wiring in the mirror heating circuit
• Oxidation or corrosion of electrical contacts and connectors
• Malfunction of the mirror heating element (broken spiral)
• Failure of the heating system control relay
• Poor contact in wiring harness connector
• Problems with ground (negative wire) in the control circuit
• Malfunction of the mirror control module or BCM (body control module)

How to Fix

1. Connect the diagnostic scanner and confirm the B1D33 code, check the freeze frames to analyze the error conditions
2. Visually inspect the wiring harness and connectors of the driver's mirror heating circuit for damage, breaks and corrosion.
3. Check the voltage at the connector of the mirror heating element in the heating mode (should be 12 volts or close to it)
4. Measure the resistance of the heating element by turning off the power (the norm is 12-20 Ohms depending on the model)
5. Check the integrity and resistance of the wiring between the control relay and the mirror, repair or remake if necessary
6. Check the condition of the heating control relay, replace if necessary
7. Clean and protect oxidized contacts with electrically conductive grease
8. Check the ground circuit (minus contact) to the heating element
9. If necessary, replace the heating element or the entire mirror assembly
10. Clear the error code and test drive to confirm the problem has been resolved.

Related codes

FAQ