A/C Control Module Requested MIL Illumination
The A/C / HVAC control module has requested the ECM to illuminate the malfunction indicator (MIL) because of an emissions-relevant fault on its side. The original fault is stored in the HVAC module — this code only signals that the ECM has honoured the request.
Affected components
- Hvac module
Common causes
- High likelihood: Internal fault in the HVAC module — read its DTCs
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
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.