Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read DTCs. Record DTC and Freeze Frame information.
3. 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.
4. With the scan tool, read DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/1 harness connector.
3. Turn the ignition on.
4. With the scan tool, monitor the O2 Sensor 1/1 voltage.
  Is the O2 Sensor 1/1 voltage between 4.1 and 5.0 volts?
  
  Yes
  - Go To 3
  No
  - Go To 5
CHECK THE O2 SENSOR 1/1
1. Measure the voltage between ground and the (K904) O2 Sensor 1/1 Return circuit at the O2 Sensor harness connector.
  Is the voltage at 2.5 volts?
  
  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 4
CHECK THE (K904) O2 SENSOR 1/1 RETURN CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Check for continuity between ground and the (K904) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  Is there continuity between ground and the (K904) O2 Sensor 1/1 Return circuit?
  
  Yes
  - Repair the (K904) O2 Sensor 1/1 Return circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
CHECK THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Check for continuity between ground and the (K41) O2 Sensor 1/1 Signal at the O2 Sensor 1/1 harness connector.
  Is there continuity between ground and the (K41) O2 Sensor 1/1 Signal?
  
  Yes
  - Repair the (K41) O2 Sensor 1/1 Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK FOR A SHORT BETWEEN THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT AND THE (K904) O2 SENSOR 1/1 RETURN CIRCUIT
1. Check for continuity between the (K41) O2 Sensor 1/1 Signal circuit and the (K904) O2 Sensor 1/1 Return circuit at the O2 Sensor 1/1 harness connector.
  Is there continuity between the (K41) O2 Sensor 1/1 Signal circuit and the (K904) O2 Sensor 1/1 Return circuit?
  
  Yes
  - Repair the short between the (K41) O2 Sensor 1/1 Signal circuit and the (K904) O2 Sensor 1/1 Return circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
CHECK FOR A SHORT BETWEEN THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT AND THE O2 SENSOR 1/1 HEATER GROUND CIRCUIT
1. Check for continuity between the (K41) O2 Sensor 1/1 Signal circuit and the O2 Sensor 1/1 Heater Ground circuit at the O2 Sensor 1/1 harness connector.
  Is there continuity between the (K41) O2 Sensor 1/1 Signal circuit and the O2 Sensor 1/1 Heater Ground circuit?
  
  Yes
  - Repair the short between the (K41) O2 Sensor 1/1 Signal circuit and the O2 Sensor 1/1 Heater Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
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 .