P1474 - Low Fan Control (LFC) Primary Circuit Failure Monitors the low fan control (LFC) (fan control [FC] for one speed fan application) primary circuit output from the PCM. The test fails if: When the PCM grounds the LFC/FC circuit, excessive current draw is detected on the LFC/FC circuit; or with the LFC/FC circuit not grounded by the PCM, voltage is not detected on the LFC/FC circuit (the PCM expects to detect VPWR voltage coming through the low speed FC relay [or CCRM] coil to the LFC/FC circuit). Open or shorted LFC/FC circuit
Open VPWR circuit to low speed FC relay
Damaged low speed FC relay (or CCRM)
Damaged PCM
When the LFCF PID reads YES, a fault is currently present
An open circuit or short to ground can only be detected when the PCM is not grounding the LFC/FC circuit
A short to power can only be detected when the PCM is grounding the LFC/FC circuit.
During KOEO and KOER Self-Test, the LFC/FC circuit will be cycled on and off