Orlando

DTC P064D - LNP or LNQ

The Heated Oxygen Sensor (HO2S) heater reduces the time required for the oxygen sensor to reach operating temperature and maintains the operating temperature during extended idle periods. When the ignition is turned to the ON position, ignition voltage is supplied directly to the sensor heater. The engine control module (ECM) controls the heater operation by first modulating the control circuit to ground when the sensors are cold. This prevents the possibility of thermal shock to the sensor, from condensation build up on the sensor, by controlling the sensors rate of heating. After a predetermined amount of time, the ECM commands the heaters ON continuously. Once the sensor reaches operating temperature, the ECM may modulate the heater control circuit to ground, to maintain a desired temperature.

The ECM controls the heater by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled up to voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

P064D 00

The ECM detects an internal fault or an over temperature when the heater is commanded ON.

DTC P064D is a Type A DTC.

DTC P064D is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Engine idling at operating temperature for at least 30 s. Observe the DTC information, DTC P064D should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the B52 Heated Oxygen Sensor.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal D and ground.

Note: The ignition circuit supplies voltage to other components. Make sure you test all circuits for a short to ground or test all components for being shorted that share the ignition circuit.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

3. Test for 3.0-4.0 V between the low reference circuit terminal C and ground.

⇒	If the voltage is less than the specified value, test the low reference circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the K20 Engine Control Module.

⇒	If the voltage is greater than the specified value, test the low reference circuit for a short to voltage. If the circuit test normal, replace the K20 Engine Control Module.

4. Ignition ON, test for 2.9 V between the B52 Heated Oxygen Sensor reference voltage circuit terminal F and ground

⇒	If less than the specified range, test the reference voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the reference voltage circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

5. Test for 2.5 V between the B52 Heated Oxygen Sensor low reference circuit terminal B and ground.

⇒	If less than the specified range, test the low reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

6. Test for 2.8 V between the B52 Heated Oxygen Sensor control circuit terminal A and ground.

⇒	If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

7. Test for 2.8 V between the B52 Heated Oxygen Sensor control circuit terminal 5 and ground.

⇒	If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

8. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
9. Test for infinite resistance between each B52 Heated Oxygen Sensor circuit terminals.

If less than the specified value, repair as necessary.

10. If all circuits/connections test normal, test or replace the B52 Heated Oxygen Sensor.

Static Test

1. Ignition OFF, disconnect the harness connector at the B52 Heated Oxygen Sensor.
2. Test the B52 Heated Oxygen Sensor resistance for 2-4 Ω.

⇒	If not within the specified range, replace the B52 Heated Oxygen Sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.