Diagnostic Test

ACTIVE DTC
1. Start the engine and allow it to idle for at least 60 seconds. Allow the engine to run long enough for the O2 Sensor to enter closed loop operation.
  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 the active DTCs.
  Is the DTC Active at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK FOR THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO ANOTHER VOLTAGE SUPPLY
1. Turn the ignition off.
2. Disconnect the Oxygen Sensor 1/2 harness connector.
3. 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.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
5. Measure the resistance between the (K141) O2 Sensor 1/2 Signal circuit and all other 5 volt and 12 volt supply circuits at the GPEC Adaptor.
  Is the resistance above 10k Ohms between the (K141) O2 Sensor 1/2 Signal circuit and all other 5 volt and 12 volt supply circuits?
  
  Yes
  - Go To 3
  No
  - Repair the (K141) O2 Sensor 1/2 Signal circuit for a short to the circuit that measured below 10k Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K141) O2 SENSOR 1/2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K141) O2 Sensor 1/2 Signal circuit between the Oxygen Sensor 1/2 harness connector to the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K141) O2 Sensor 1/2 Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K902) O2 SENSOR 1/2 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K902) O2 Sensor 1/2 Return circuit between the Oxygen Sensor 1/2 harness connector to the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K902) O2 Sensor 1/2 Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
OXYGEN SENSOR 1/2
1. Turn the ignition off.
2. Reconnect the Powertrain Control Module (PCM) harness connector.
3. Connect a jumper between the (K141) O2 Sensor 1/2 Signal circuit and the (K902) O2 Sensor 1/2 Return circuit in the Oxygen Sensor 1/2 harness connector.
4. Turn the ignition on.
5. With a scan tool, monitor the O2 Sensor 1/2 volts.
  NOTE:
  The sensor should read at or very neat zero volts with the jumper in place.
  
  Is the voltage at or very neat zero volts with the jumper in place?
  
  Yes
  - Replace the Oxygen Sensor 1/2 in accordance with the service information. Refer to SENSOR, OXYGEN, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/2 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.
4. Perform any Technical Service Bulletins (TSBs) that may apply.
  Were 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 (PCM) in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .