Diagnostic Test

ACTIVE DTC
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. With a scan tool, View DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT DTC diagnostic procedure. Refer to CHECKING FOR AN INTERMITTENT DTC .
CHECK THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/1 harness connector.
3. Disconnect the PCM C1 harness connector.
4. Measure the resistance of the (K41) O2 Sensor 1/1 Signal circuit between the O2 Sensor 1/1 harness connector and the PCM C1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (K41) O2 Sensor 1/1 Signal circuit for an open or high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K902) O2 1/1 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K902) O2 1/1 Return circuit between the O2 Sensor 1/1 harness connector and the PCM C1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K902) O2 1/1 Return circuit for an open or high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 1/1 RETURN UPSTREAM CIRCUIT
1. Measure the resistance between the (K41) O2 Sensor 1/1 Signal circuit and the (K902) O2 Return circuit at the O2 Sensor harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the short between the (K902) O2 1/1 Return circuit and the (K41) O2 Sensor 1/1 Signal circuit.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
O2 SENSOR
1. Replace the O2 Sensor.
2. Reconnect the O2 Sensor 1/1 harness connector.
3. Reconnect the PCM C1 harness connector.
4. Start the engine.
5. Allow the engine to reach normal operating temperature.
6. With a scan tool, View DTCs.
  Did the DTC return?
  
  Yes
  - Go To 6
  No
  - Repair is complete.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE
NOTE:
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM 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 PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .