Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. Wait 15 seconds with the ignition on and then start the engine. Allow the vehicle to warm up to operating temperature.
3. With a scan tool, read and record DTCs on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE VOLTAGE SUPPLY TO THE RADIATOR FAN HIGH RELAY
1. Turn the ignition off.
2. Disconnect the Radiator Fan High Relay harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, probe (A212) Fused B+ circuit at the Radiator Fan High Relay harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a connection to direct Battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go To 3
  No
  - Check for any open fuses in the PDC. If a fuse is open, check the (A212) Fused B+ circuit to the Radiator Fan High Relay and the (N23) circuit to the Radiator Fan for a short to ground and repair as necessary. If the fuses are good, diagnose and repair the reason for no Battery voltage on the (A212) Fused B+ circuit between the PDC and Radiator Fan High Relay and perform the appropriate repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K173) RADIATOR FAN RELAY 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) Radiator Fan Relay Control circuit at the Radiator Fan High Relay harness connector.
  Is there continuity between ground and the (K173) Radiator Fan Relay Control circuit?
  
  Yes
  - Repair the (K173) Radiator Fan Relay Control circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (K173) RADIATOR FAN RELAY 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 adapter.
  (special tool #10436, Adapter, GPEC Diagnostic)
2. Measure the resistance of the (K173) Radiator Fan Relay Control circuit between the Radiator Fan High Relay harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K173) Radiator Fan Relay Control circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE RADIATOR FAN HIGH RELAY
1. With a scan tool, select Radiator Fan 1 Relay Control State, Toggle, to actuate the Cooling Fan.
2. Using a 12-volt test light connected to Battery voltage, probe the (K173) Radiator Fan Relay Control circuit at the Radiator Fan High Relay connector.
  Does the test light illuminate brightly and flash on and off during the actuation?
  
  Yes
  - Replace the Radiator Fan High Relay.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Powertrain Control Module in accordance with the Service information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.