P0038

P0038-O2 SENSOR 1/2 HEATER CIRCUIT HIGH





For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.

- When Monitored:
Battery voltage above 10.6 volts, ASD is powered up, and O2 heater is off.

- Set Condition:
Desired state does not equal Actual state. Two Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With a scan tool, select View DTCs.

Is the DTC Active or Pending at this time?

Yes

- Go To 3

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking for an Intermittent DTC.

2. (K299) O2 1/2 HEATER CONTROL CIRCUIT




1. Ignition on, engine not running.

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.

2. With a scan tool, actuate the O2 1/2 Heater Test with the O2 Sensor harness connector still disconnected.
3. Using a 12-volt test light connected to 12-volts, probe the (K299) O2 1/2 Heater Control circuit in the O2 Sensor harness connector.

Does the test light illuminate brightly and flash on and off during the actuation?

Yes

- Go To 3

No

- Go To 4

3. O2 HEATER ELEMENT




1. Turn the ignition off.

NOTE: Allow the O2 Sensor to cool down to room temperature.

2. Disconnect the 1/2 O2 Sensor harness connector.
3. Measure the resistance across the O2 Sensor Heater element, between the Heater Control terminal and the 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 2.0 and 30.0 ohms?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking for an Intermittent DTC.

No

- Replace the O2 Sensor.
- Perform the PCM Verification Test.PCM Verification Test

4. (K299) O2 1/2 HEATER CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE




1. Turn the ignition off.
2. Disconnect the C1 PCM harness connector.
3. Ignition on, engine not running.
4. Using a 12-volt test light connect to ground, probe the (K299) O2 1/2 Heater Control circuit in the O2 Sensor harness connector.

Does the test light illuminate brightly?

Yes

- Repair the short to battery voltage in the (K299) O2 1/2 Heater Control circuit.
- Perform the PCM Verification Test.PCM Verification Test

No

- Go To 5

5. (K299) O2 1/2 HEATER CONTROL CIRCUIT OPEN




1. Turn the ignition off.
2. Measure the resistance of the (K299) O2 1/2 Heater Control circuit from the O2 Sensor harness connector to the C1 PCM harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 6

No

- Repair the open in the (K299) O2 1/2 Heater Control circuit.
- Perform the PCM Verification Test.PCM Verification Test

6. 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. Search for any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test.PCM Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the PCM Verification Test.PCM Verification Test