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 (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Disconnect the O2 Sensor 1/1 harness connector.
4. Turn the ignition on.
5. Measure the voltage between ground and the (K41) O2 Sensor 1/1 Signal circuit in the O2 Sensor 1/1 harness connector.
  NOTE: Measure the voltage in reference to ground, not the (K902) O2 Sensor 1/1 Return circuit.
  
  Is there any voltage present?
  
  Yes
  - Repair the (K41) O2 Sensor 1/1 Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (K902) O2 SENSOR 1/1 RETURN CIRCUIT FOR A SHORT TO VOLTAGE
1. Measure the voltage between ground and the (K902) O2 Sensor 1/1 Return Upstream circuit in the O2 Sensor 1/1 harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K902) O2 Sensor 1/1 Return Upstream circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
O2 SENSOR 1/1
1. Turn the ignition off.
2. Reconnect the PCM C2 harness connector.
3. Turn the ignition on.
4. With the scan tool, monitor the O2 Sensor 1/1 voltage.
5. Connect a jumper between the (K41) O2 Sensor 1/1 Signal circuit and the (K902) O2 Sensor 1/1 Return Upstream circuit in the O2 Sensor harness connector.
  Is the voltage between 2.3 and 2.7 volts with the jumper installed?
  
  Yes
  - Verify that there is good pin to terminal contact in the O2 Sensor 1/1 and Powertrain Control Module connectors. If OK, replace the O2 Sensor 1/1. Refer to SENSOR, OXYGEN, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
    NOTE: Remove the jumper before continuing.
CHECK THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
  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.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
4. Measure the resistance of the (K41) O2 Sensor 1/1 Signal circuit from the O2 Sensor 1/1 harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (K41) O2 Sensor 1/1 Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K902) O2 SENSOR 1/1 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance between ground and the (K902) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (K902) O2 Sensor 1/1 Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Oxygen Sensor 1/1 and Powertrain Control Module connectors.
4. Perform any Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .