A/C Request B Circuit Range/Performance
A/C request input B is electrically intact but its value does not match the system context — same failure mode as the input A performance fault, applied to the second HVAC channel.
Affected components
- Ac request input b
Common causes
- High likelihood: HVAC module sending inconsistent request B
- Low likelihood: Sensor element aged beyond calibration window
- Low likelihood: Sensor mounting loose - signal damping
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.