Diagnostic Test
- RADIATOR FAN OPERATION NOTE:
Diagnose and repair any Radiator Fan Relay Control circuit DTCs before proceeding with this test.
- Turn the ignition on, engine not running.
- Using a scan tool, actuate the low speed fan.
- Using a scan tool, actuate the high speed fan.NOTE:
During high speed actuation the Radiator Fan Motor is easily audible.
Does the fan operate in both speeds?
Yes
- The Radiator Fan is operating normal at this time.
- Perform the INTERMITTENT CONDITION test procedure. For 3.6L, refer to INTERMITTENT CONDITION . For 5.7L, refer to INTERMITTENT CONDITION . For 6.2L, refer to INTERMITTENT CONDITION . For 6.4L, refer to INTERMITTENT CONDITION .
No, the Radiator Fan does not operate for either speed
- Go To 2
No, only the low speed is operating
- Go To 4
No, only the high speed is operating
- Go To 6
- CHECK THE RADIATOR FAN B+ SUPPLY VOLTAGE AT THE FAN MOTOR
- Stop the actuation.
- Using a voltameter, back probe the B+ supply circuit at the Radiator Fan Motor connector.
- Using a scan tool, actuate the high speed fan.
- Measure the voltage at the B+ supply circuit at the Radiator Fan Motor connector.
Is the voltage equal to Battery voltage?
Yes
- Go To 3
No
- Repair the B+ supply circuit for an open or high resistance in the Radiator Fan Assembly wiring harness between the Radiator Fan Assembly harness connector and the Radiator Fan Motor connector.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE RADIATOR FAN MOTOR AND GROUND CIRCUIT
- Stop the actuation.
- Using a voltameter, back probe the ground circuit at the Radiator Fan Motor connector.
- Using a scan tool, actuate the high speed fan.
- Measure the voltage at the ground circuit at the Radiator Fan Motor connector.NOTE:
Voltage present on the ground circuit with the connector plugged in indicates an open or high resistance in the ground circuit.
Is there any voltage present?
Yes
- Repair the Radiator Fan Motor Ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
No
- Replace the Radiator Fan Motor in accordance with the Service Information
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (N23) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- Turn the ignition off.
- Disconnect the Radiator Fan Motor connector.
- Remove the Radiator Fan Relay 3 (Med/High) from the PDC.
- Measure the resistance of the (N23) circuit between the Radiator Fan Motor connector and terminal 30 of the Radiator Fan High Relay connector.
Is the resistance below 3.0 Ohms?
Yes
- Go To 5
No
- Repair the (N23) circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE BATTERY SUPPLY CIRCUIT
- Turn the ignition on.
- Using a 12-volt test light connect to ground, probe the Battery Supply circuit at the relay connector (terminal 30).
Is the test light illuminated and bright?
Yes
- Replace the Radiator Fan High Relay.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
No
- If the fuse is blown, check the (N23) circuit for a short to ground and repair as necessary. If the fuse is not blown, replace the Powertrain Distribution Center (PDC) in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE RADIATOR FAN ASSEMBLY WIRING HARNESS LOW SPEED CONTROL CIRCUIT FOR AN OPEN
- Turn the ignition off.
- Disconnect the Radiator Fan Assembly harness connector.
- Disconnect the Radiator Fan Motor connector.
- Check the Low Speed Rad Fan Control circuit for an open circuit between the Radiator Fan Assembly harness connector and the Radiator Fan Motor connector.NOTE:
There will be some resistance in the circuit do to the resistor at the Radiator Fan Assembly harness connector in the Low Speed Rad Fan Control circuit for low speed operation.
Is the Low Speed Rad Fan Control circuit open?
Yes
- Repair the Low Speed Rad Fan Control circuit for an open.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 7
- CHECK THE (N24) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- Remove the Radiator Fan Relay 1 (High/Low) from the PDC.
- Measure the resistance of the (N24) circuit between the Radiator Fan Assembly harness connector and terminal 87 of the Radiator Fan Relay 1 (High/Low) connector.
Is the resistance below 3.0 Ohms?
Yes
- Go To 8
No
- Repair the (N24) circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE RADIATOR FAN BATTERY SUPPLY CIRCUIT
- Remove the Radiator Fan Relay 1 (High/Low) from the PDC.
- Turn the ignition on.
- Using a 12-volt test light connect to ground, probe the Battery Feed circuit at the relay connector (terminal 30).
Is the test light illuminated and bright?
Yes
- Replace the Radiator Fan Relay.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .
No
- If the fuse is blown, check the (N24) circuit for a short to ground and repair as necessary. If the fuse is not blown, replace the Powertrain Distribution Center (PDC) in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, refer to POWERTRAIN VERIFICATION TEST . For 5.7L, refer to POWERTRAIN VERIFICATION TEST . For 6.2L, refer to POWERTRAIN VERIFICATION TEST . For 6.4L, refer to POWERTRAIN VERIFICATION TEST .