A/C Request B Circuit High
The A/C request input B reads stuck high — typically a short to battery voltage. The ECM cannot read the switch state, request B is treated as invalid.
Affected components
- Ac request input b
Common causes
- High likelihood: Request wire shorted to battery voltage
- Low likelihood: Connector pins corroded - high contact resistance
- Low likelihood: Supply wire pinched against B+ source
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.