X15 - Check High Fan Control (HFC) Relay Resistance

Diagnostic Trouble Code (DTC) 1479 indicates a High Fan Control (HFC) primary circuit failure.

NOTE: For one speed fan applications, disregard DTC 1479.

Possible causes are:
- Open or shorted circuit.
- Damaged CCRM.
- Damaged PCM.

- Key Off.

- Disconnect CCRM.

- Measure resistance between Pin 17 and Pin 24 at the CCRM.

- Is the resistance between 50 and 100 ohms?

YES -- GO to X16. X16 - Check HFC Circuit Continuity

NO -- REPLACE CCRM. Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes