Diagnostic Test

RADIATOR COOLING FAN MODULE OPERATION
1. Turn the ignition on.
2. With a scan tool, select Radiator Cooling Fan Control State to actuate the Cooling Fan.
  Is the Cooling Fan operating?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Go To 2
CHECK THE (A13) FUSED B+ CIRCUIT
1. Stop the actuation of the Cooling Fan. Leave the ignition on.
2. Disconnect the Cooling Fan harness connector.
3. Measure the voltage between ground and the (A13) Fused B+ circuit at the Radiator Fan harness connector.
  Is the voltage equal to battery voltage?
  
  Yes
  - Go To 3
  No
  - Repair the (A13) Fused B+ circuit for an open circuit. If the fuse is found to be blown, check the circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (Z905) GROUND CIRCUIT FOR AN OPEN
1. Measure the resistance between ground and the (Z905) Ground circuit at the Radiator Fan harness connector.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (Z905) Ground circuit for an open.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K173) PWM RADIATOR FAN CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Check for continuity between ground and the (K173) PWM Radiator Fan Control circuit at the Radiator Fan harness connector.
  Is there continuity between ground and the (K173) PWM Radiator Fan Control circuit?
  
  Yes
  - Repair the (K173) PWM Radiator Fan Control circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (K173) PWM RADIATOR FAN CONTROL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
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 the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
2. Measure the resistance of the (K173) PWM Radiator Fan Control circuit between the Radiator Fan harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (K173) PWM Radiator Fan Control circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE RADIATOR FAN
1. Reconnect the PCM C1 harness connector.
2. Reconnect the Radiator Fan harness connector.
3. Using a voltmeter, back probe the (K173) PWM Radiator Fan Control circuit at the Radiator Fan harness connector.
4. Turn the ignition on.
5. With the scan tool actuate the Cooling Fan.
  NOTE:
  Because this is a PWM signal circuit, the voltage reading can vary depending on the cooling fan speed requested.
  
  Is there any voltage present?
  
  Yes
  - Replace the Radiator Fan Assembly in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .