2007 Liberty KJ Factory Service Manual 9 - ENGINE

P0480-FAN 1 CONTROL CIRCUIT EXCESSIVE CURRENT





For a complete wiring diagram Refer to Section 8W



Possible Causes
 
INTERMITTENT CONDITION
 
LOW SPEED RADIATOR FAN RELAY
 
(N201) LOW SPEED RADIATOR FAN CONTROL CIRCUIT SHORTED TO VOLTAGE
 
ENGINE CONTROL MODULE
 




Diagnostic Test

1. CHECK FOR ACTIVE DTC

NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.


NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.


Turn the ignition on.
With the scan tool, actuate the Low Speed Radiator Fan Relay.

Does the Radiator Fan cycle on and off?

Yes


No

2. LOW SPEED RADIATOR FAN RELAY

Turn the ignition off.
Install a know good relay in place of the Low Speed Radiator Fan Relay.
Turn the ignition on.
With the scan tool, actuate the Low Speed Radiator Fan Relay.

Does the Radiator Fan cycle on and off?

Yes


No

3. (N201) LOW SPEED RADIATOR FAN CONTROL CIRCUIT SHORTED TO VOLTAGE



Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the Low Speed Radiator Fan Relay from the PDC.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Turn the ignition on.
Measure the voltage of (N201) Low Speed Radiator Fan Control circuit.

Is the voltage below 1.0 volt?

Yes


No