Diagnostic Test

OXYGEN SENSOR 1/2 HEATER CONTROL OPERATION
1. Turn the ignition off.
  NOTE:
  Wait a minimum of 8 minutes to allow the sensor to cool down before continuing. The sensor voltage should stabilize between 2.47 and 2.52 volts.
2. Turn the ignition on.
3. With a scan tool, actuate the Oxygen Sensor 1/2 heater control.
4. With the scan tool, monitor O2 Sensor 1/2 volts for at least two minutes.
  Does the voltage stay between 2.47 and 2.52 volts?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
OXYGEN SENSOR 1/2
1. Turn the ignition off.
  NOTE:
  Wait a minimum of 8 minutes to allow the sensor to cool down before continuing.
2. Disconnect the Oxygen Sensor 1/2 harness connector.
3. Measure the resistance of the O2 Sensor 1/2 heater element across the Oxygen Sensor 1/2 connector between the (K299) heater control terminal and the (Z904) ground terminal.
  NOTE:
  The O2 heater element resistance should be measured at 70°F (21.1°C). The resistance value will vary at different temperatures.
  
  Is the resistance between 2.0 and 30.0 Ohms?
  
  Yes
  - Go To 3
  No
  - 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 .
HIGH RESISTANCE IN THE (K299) O2 SENSOR 1/2 HEATER CONTROL CIRCUIT
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 of the (K299) O2 Sensor 1/2 Heater Control circuit between the Oxygen Sensor 1/2 harness connector and the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K299) O2 Sensor 1/2 Heater Control circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR HIGH RESISTANCE IN THE (Z904) GROUND CIRCUIT
1. Measure the resistance between a good chassis ground and the (Z904) Ground circuit in the O2 Sensor harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the excessive resistance in the (Z904) Ground circuit.
  - 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 1/2 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 .