Rear AC Blower Motor Speed 2 Circuit Failure
The B2563 code indicates that the Body Control Module (BCM) or rear HVAC control module has detected a fault in the speed 2 control circuit for the auxiliary (rear) air conditioning blower motor. This typically points to an open circuit, short to ground, or short to voltage in the wiring that powers the rear blower resistor or control module, preventing that specific fan speed from working properly.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty rear blower motor control module or resistor
- Damaged, shorted, or open wiring between the rear HVAC module and the blower motor/resistor
- Corroded, loose, or pushed-out terminals in the auxiliary blower circuit connectors
- Rear auxiliary blower motor with excessive internal short
- Defective rear HVAC control module
3. Symptoms You Will Notice
- Rear AC blower does not operate at speed 2, but may work at other speeds
- Inoperative rear air conditioning or heating
4. Step-by-Step Diagnosis
Scan for additional codes and check freeze frame data
Inspect rear blower motor resistor/module and wiring for damage or corrosion
Test voltage and ground at the blower motor connector with speed 2 selected
Check continuity and resistance in the speed 2 control circuit
If wiring and connector are okay, test the blower motor and control module per service manual
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but rear climate control will be limited. The issue is electrical and does not affect vehicle safety.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the blower motor resistor, control module, or wiring needs replacement.