Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
If an O2 sensor signal circuit is shorted to voltage, all O2 Sensor voltage readings displayed on the scan tool will be approximately 5.0 volts. Diagnose the sensor that set the most current DTC.
1. Start the engine and allow it to idle for at least 60 seconds.
  WARNING:
  When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool, read DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/2 harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (K141) O2 Sensor 1/2 Signal circuit in the O2 Sensor 1/2 harness connector.
  Is the voltage above 5.2 volts?
  
  Yes
  - Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
MEASURE THE VOLTAGE ON (K141) O2 SENSOR 1/2 ON THE PCM C2 HARNESS CONNECTOR
1. Reconnect the PCM C2 harness connector.
2. Turn the ignition on.
3. With the scan tool, monitor the O2 Sensor 1/2 voltage.
4. Connect a jumper between the (K141) O2 Sensor 1/2 Signal circuit and the (K902) O2 Sensor Upstream Return circuit at the O2 Sensor harness connector.
  Is the voltage between 2.3 and 2.7 volts on the scan tool with the jumper installed?
  
  Yes
  - Verify that there is good pin to terminal contact in the O2 Sensor 1/2 and Powertrain Control Module 1 connectors. If no problems are found, replace the O2 Sensor 1/2. Refer to SENSOR, OXYGEN, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Remove the jumper before continuing.
  - Go To 4
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 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 .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.