TEST
ACTION
APPLICABILITY
3
Turn the ignition off.
Install a substitute relay in place of the Radiator Fan Relay No. 1.
Turn the ignition on.
With the DRB, actuate the Low Speed Radiator Fan Relay.
Do the Radiator Fans cycle on and off?
All
Yes
→ Replace Radiator Fan Relay No. 1.
Perform ROAD TEST VERIFICATION - VER-2.
No
→ Go To 4
4
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Radiator Fan Relay No. 1 harness connector.
Remove the ECM/PCM Relay from the IPM.
Connect a jumper wire between cavity 30 and cavity 87 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage of the Low Speed Radiator Fan Control circuit.
Is the voltage below 1.0 volt?
All
Yes
→ Go To 5
No
→ Repair the Low Speed Radiator Fan Control circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
5
If there are no possible causes remaining, view repair.
All
Repair
Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
87
DRIVEABILITY - DIESEL
P0480-FAN 1 CONTROL CIRCUIT SHORT CIRCUIT —
Continued