Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT DTC .
CHECK THE O2 SENSOR 1/1 (K79) HEATER CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Disconnect the O2 Sensor 1/1 harness connector.
2. Measure the voltage on the O2 Sensor 1/1 (K79) Heater Control circuit in the O2 Sensor 1/1 harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the O2 Sensor 1/1 (K79) Heater Control circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE ASD RELAY (F343) OUTPUT CIRCUIT FOR HIGH RESISTANCE BY LOAD TESTING THE CIRCUIT
NOTE:
Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool and for additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT TESTING PROCEDURES .

NOTE:
An open ASD Relay output or heater control circuit will typically set a heater circuit low fault with one exception. During a cold start, in extreme cold ambient temperatures, the heater circuit high fault can set if there is an open in the heater circuitry.

CAUTION:
Do not load test any circuits with components still connected to the circuit.
1. Load test the ASD Relay (F343) Output circuit at the O2 Sensor 1/1 harness connector. Note: refer to the example illustration.
2. NOTE:
  The bulb on the load test tool should be illuminated and bright if there is no resistance in the circuitry. Compare the brightness of the bulb in the load test tool to that of a direct connection across Battery.
  
  Is the load test bulb illuminated and bright?
  
  Yes
  - Go To 4
  No
  - Repair the ASD Relay (F343) Output circuit for an open or high resistance. If the fuse is found to be open, check the circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
REPLACE THE O2 SENSOR 1/1 AND RETEST FOR DTCS
1. Turn the ignition off.
2. Replace the O2 Sensor 1/1 in accordance with the Service Information.
3. Connect all disconnected harness connectors.
4. Turn the ignition on.
5. With the scan tool, erase all DTCs.
6. Turn the ignition off for a minimum of 10.0 seconds.
7. Turn the ignition on.
8. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
9. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 5
  No
  - Replacing the faulty O2 Sensor repaired the fault.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. 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.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .
  No
  - Repair the poor connections.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.0L, POWERTRAIN VERIFICATION TEST .