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DTC P064D

DTC P064D

Diagnostic Instructions


• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• Diagnostic Procedure Instructions provides an overview of each diagnostic category.


DTC Descriptors

DTC P064D 39

Control Module HO2S 1 System Circuitry Performance

DTC P064D 3B

Control Module HO2S 1 System Circuitry Performance

DTC P064D 54

Control Module HO2S 1 System Circuitry Performance

Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Ignition Voltage

P0030 00

P0030 00

-

P0131 5A, P0131 12

HO2S Heater Control Sensor 1

P0031 00

P0030 00

P0032 00

P064D 39, P064D 3B, P064D 54



Circuit/System Description

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.

Conditions for Running the DTC


• The ignition voltage is between 10-18 V.

• The engine speed is more than 80 RPM.

• The HO2S heater is commanded ON and OFF at least once during the ignition cycle.

• The DTCs run continuously once the above conditions are met for 2 s.


Conditions for Setting the DTC

P064D 39 and P064D 3B

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

P064D 54

The ECM detects an over temperature on the output powerstage of the HO2S when the heater is commanded ON.

Action Taken When the DTC Sets

DTC P064D is a Type A DTC.

Conditions for Clearing the DTC

DTC P064D is a Type A DTC.

Diagnostic Aids


• If the condition is intermittent, move the harnesses and connectors, with the engine operating, while monitoring the scan tool Circuit Status parameters for the component. The Circuit Status parameters change from OK or Not Run to Fault if there is a condition with the circuit or a connection.

• An open fuse in the HO2S heater circuit may be caused by the heater element. The condition may not be present until the sensor operates for a period of time. If no fault is present in the heater circuit, monitor the amperage of the heater using the DMM to determine if the heater element is the cause of the open fuse. Inspect the sensor pigtail or the harness for contacting the exhaust system.


Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference


• Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification


1. Let the engine idle at working temperature for at least 30 seconds. Read DTC information. DTC P064D should not be indicated.

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.


Circuit/System Testing


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 4 and ground.

3.
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.

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

5. 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.

6. 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.

7. Ignition ON, test for 2.9 V between the B52 Heated Oxygen Sensor reference voltage circuit terminal 6 and ground

8. 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.

9. 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.

10. Test for 2.5 V between the B52 Heated Oxygen Sensor low reference circuit terminal 2 and ground.

11. 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.

12. 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.

13. Test for 2.8 V between the B52 Heated Oxygen Sensor control circuit terminal 1 and ground.

14. 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.

15. 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.

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

17. 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.

18. 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.

19. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.

20. Test for infinite resistance between each B52 Heated Oxygen Sensor circuit terminals.

If less than the specified value, repair as necessary.

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


Component Testing


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.

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


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Heated Oxygen Sensor Replacement (LBY/A20DTR) Heated Oxygen Sensor Replacement (LBS/A20DTH)

• Control Module References for Engine Control Module replacement, setup, and programming