Diagnostic Procedure
DIAGNOSTIC PROCEDURES - P0480-LOW SPEED FAN CONTROL RELAY CIRCUIT
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 | Ignition on, engine not running. With the DRBIII®, actuate the Radiator Fan Relay. Is the Low Speed Radiator Fan Relay operating? Yes --> Refer to the INTERMITTENT CONDITION SYMPTOM . Perform POWERTRAIN VERIFICATION TEST VER - 5 . No --> Go To 2 |
All |
| 2 | Turn the ignition off. Remove the Low Speed Radiator Fan Relay from the PDC. Ignition on, engine not running. Measure the voltage of the (A16) Fused B+ Feed circuit in the PDC. Is the voltage above 11.0 volts? Yes --> Go To 3 No --> Repair the (A16) Fused B+ Output circuit. Inspect the related fuse and repair as necessary. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
All |
| 3 | Turn the ignition off. Remove the Low Speed Radiator Fan Relay from the PDC. Measure the resistance of the Low Speed Radiator Fan Relay between the Fused Ignition Switch Output terminal and the Low Speed Rad Fan Relay Control terminal. Is the resistance between 60 to 85 ohms? Yes --> Go To 4 No --> Replace the Low Speed Radiator Fan Relay. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
All |
| 4 | Turn the ignition off. Remove the Low Speed Radiator Fan Relay from the PDC. Disconnect the PCM harness connector.
CAUTION:
DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Measure the resistance of the (C24) Low Speed Rad Fan Relay Control circuit from the PDC to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes --> Go To 5 No --> Repair the open in the (C24) Low Speed Rad Fan Relay Control circuit. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
All |
| 5 | Turn the ignition off. Remove the Low Speed Radiator Fan Relay from the PDC. Disconnect the PCM harness connector. Measure the resistance between ground and the (C24) Low Speed Rad Fan Control circuit at the PDC. Is the resistance below 100 ohms? Yes --> Repair the short to ground in the (C24) Low Speed Rad Fan Relay Control circuit. Perform POWERTRAIN VERIFICATION TEST VER - 5 . No --> Go To 6 |
All |
| 6 |
NOTE:
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. If there are no possible causes remaining, view repair.RepairReplace and program the Powertrain Control Module in accordance with the Service Information.Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
All |