X75 - DTC 1480: Check Power-to-Fan and B(+) to FC/LFC Relay

Continuous Memory Diagnostic Trouble Code (DTC) 1480 indicates that sometime while the (low speed) fan was on, the Fan Monitor (FANM) circuit went low.

Possible Causes:
- Open in Power-to-(Low Speed) Fan circuit between the B(+) supply to the CCRM and the FANM splice into circuit.
- Open in B(+) circuit to CCRM (FC/LFC relay).

- Key Off.

- Scan Tool connected.

- Disconnect cooling fan connector.

- Connect a non-powered test lamp between the Power-to-(Low Speed) Fan circuit and ground circuit at the cooling fan vehicle harness connector.

- Key On, Engine Off.

- Access Output Test Mode on Scan Tool.

- Command Low Speed Fan On.

- Observe test lamp for an indication of a fault while performing the following (the lamp will turn off when a fault is detected, indicating an open):
- Shake, wiggle, bend the Power-to-(Low Speed) Fan circuit between the CCRM and the FANM splice to circuit.
- Shake, wiggle, bend the B(+) circuit between the B(+) supply and the CCRM (Pins 3 and 4).
- Lightly tap on the CCRM to simulate road shock.

- Key Off.

- Is a fault Indicated?

YES -- ISOLATE fault and SERVICE as necessary. Complete PCM reset to clear DTCs. Clearing Diagnostic Trouble Codes

Rerun quick test. Diagnostic Subroutines (DSR) - Extracting Codes

NO -- GO to Pinpoint Test Step Z1 with the following data: FANM and FCA/LFCA PIDs (to verify when (low speed) fan is commanded on) and list of Possible Causes. Z1 - Intermittent Test Procedure