Diagnostic Test

O2 SENSOR HEATER OPERATION
1. Turn the ignition off.
  NOTE:
  Wait a minimum of 8 minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize at 5.0 volts.
2. Ignition on, engine not running.
3. With a scan tool, actuate the O2 1/1 Heater Test.
  NOTE:
  The DTC needs to be cleared before actuating the Heater Test, if the DTC is not cleared, the Heater Test may not be allowed to actuate.
4. With the scan tool, monitor O2 Sensor 2/2 voltage for at least 2 minutes.
  Does the O2 Sensor voltage stay above 4.5 volts?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
O2 HEATER ELEMENT
1. Turn the ignition off.
  NOTE:
  Allow the O2 Sensor to cool down to room temperature.
2. Disconnect the O2 Sensor 2/2 harness connector.
3. Measure the resistance across the O2 Sensor Heater element, between the O2 Heater Control terminal and the O2 Heater ground terminal at the component.
  NOTE:
  O2 Heater Element resistance values should be measured at 21.1° C (70° F). The resistance value will vary with different temperature values.
  
  Is the O2 Sensor Heater Element resistance between 2.88 and 13.0 ohms?
  
  Yes
  - Go To 3
  No
  - Replace the O2 Sensor.
  - Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
O2 SENSOR
1. Ignition on, engine not running.
2. With a scan tool, actuate the O2 Heater Test.
  NOTE:
  The DTC needs to be cleared before actuating the Heater Test, if the DTC is not cleared, the Heater Test may not be allowed to actuate.
3. Using a 12-volt test light connected to 12 volts, probe the (K399) O2 2/2 Heater Control circuit in the O2 Sensor harness connector.
  Does the test light illuminate brightly and flash on and off during the actuation?
  
  Yes
  - Replace the O2 Sensor.
  - Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 4
CHECK THE (K399) O2 2/2 HEATER CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance between ground and the (K399) O2 2/2 Heater Control circuit in the O2 Sensor harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K399) O2 2/2 Heater Control circuit for a short to ground.
  - Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 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. Verify that there is good pin to terminal contact in the Oxygen Sensor and Powertrain Control Module connectors.
5. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
6. Look for the data to change or for a DTC to set during the wiggle test.
7. Refer to any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace and program the Powertrain Control Module in accordance with the service information.
  - Perform the PCM VERIFICATION TEST. Refer to STANDARD PROCEDURE .