X15 - Code 563: Check High Fan Control (HFC) Circuit In CCRM

Diagnostic Trouble Code (DTC) 563 indicates a High Fan Control (HFC) primary circuit failure.

Possible causes are:
- Open or shorted circuit.
- Damaged Constant Control Relay Module (CCRM).
- Damaged Powertrain Control Module (PCM).

- Key "OFF".

- Disconnect CCRM.

- Check High Fan Control (HFC) relay resistance in CCRM:
- Measure resistance between Pin 17 and Pin 24 at the CCRM.
- Resistance should be between 50 and 100 ohms.

- Check HFC circuit for shorts in CCRM:
- Measure resistance between Pin 17 and Pins 1 through 8 of the CCRM.
- Also measure resistance between Pin 17 and the CCRM case.
- All resistence should be greater than 10,000 ohms.

- Are all checks OK?

Yes -- Go to X17. X17 - Check HFC Circuit Continuity

No -- Replace CCRM. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)