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DTC P0030-P0032, or P0135 (LLU)

DTC P0030-P0032, or P0135 (LLU)

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 Descriptor

DTC P0030 00

HO2S Heater Control Circuit Sensor 1

DTC P0031 00

HO2S Heater Control Circuit Low Voltage Sensor 1

DTC P0032 00

HO2S Heater Control Circuit High Voltage Sensor 1

DTC P0135 00

HO2S Heater Performance Sensor 1

Diagnostic Fault Information

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

P0030 00, P0033 00, P0036 00, P0102 00, P0135 00, P0141 00

P0030 00, P0031 00, P0032 00, P0135 00

-

P0135 00

Heater Control

P0030 00, P0135 00,

P0030 00, P0132 00, P0135 00

P0030 00, P0135 00

P0135 00



Circuit/System Description

The heated oxygen sensors 1 or 2 are used for fuel control and catalyst monitoring. Each heated oxygen sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an open loop mode, ignoring the heated oxygen sensor signal voltage while calculating the air to fuel ratio. The control module supplies the heated oxygen sensor with a reference, or bias voltage of about 450 mV. While the engine runs, each heated oxygen sensor heats up and begins to generate a voltage within a range of 0-1000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient heated oxygen sensors 1 or 2 voltage fluctuation is observed by the control module, closed loop is entered. The control module uses the heated oxygen sensor voltage to determine the air to fuel ratio. An heated oxygen sensor voltage that increases above bias voltage toward 1000 mV indicates a rich fuel mixture. An heated oxygen sensor voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.

The heating elements inside each heated oxygen sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter closed loop earlier and the control module to calculate the air to fuel ratio sooner.

Conditions for Running the DTC


P0030 00, P0031 00, and P0032 00

The engine speed is greater that 40 RPM.

The ignition voltage is between 11-18 V.

DTC P0030 00, P0031 00, and P0032 00 run continuously when the above conditions are met for 1 s.



P0135 00

DTCs P0030 00, P0031 00, P0032 00 are not set.

The engine speed is greater that 25 RPM.

The ignition voltage is between 11-18 V.

DTC P0135 00 runs continuously.


Conditions for Setting the DTC


P0030 00, P0031 00, and P0032 00

The ECM detects that the difference between the predicted voltage and the actual voltage exceeds a calibrated limit for 0.5 s.

DTCs P0030 00, P0031 00, and P0032 00 set when the above condition is met.


P0135 00

The ECM detects that the heated oxygen sensor 1 heater resistance is more than 1200 Ω for 20 s.

Action Taken When the DTC Sets

DTC P0030 00, P0031 00, P0032 00, P0135 00 are Type B DTCs.

Conditions for Clearing the DTC

DTC P0030 00, P0031 00, P0032 00, P0135 00 are Type B DTCs.

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. Clear the DTCs with a scan tool.

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 are captured in the freeze frame/failure records data.


Circuit/System Testing

Note

You must perform the circuit/system verification before proceeding with circuit/system testing.



1. Ignition OFF, disconnect the harness connector at the B52A Heated Oxygen Sensor 1.

2. Ignition ON, test for B+ between the B52A Heated Oxygen Sensor 1 ignition voltage circuit terminal 1 and ground.

3. If less than the specified range, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse F11 is open, test all components connected to the ignition voltage circuit and replace as necessary.

4. Connect a test lamp between the heater control circuit terminal 2 and B+. The test lamp should not illuminate.

5. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit test normal, replace the K20 Engine Control Module.

6. Idle the engine, and verify the test lamp illuminates or flashes.

7. If the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the K20 Engine Control Module.

8. Ignition ON, test for 2-3 V between the B52A Heated Oxygen Sensor 1 control circuit terminal 2 and ground.

9. 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.

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

11. If all circuits test normal, test or replace the B52A Heated Oxygen Sensor 1.


Component Testing


Static Test

1. Ignition OFF, disconnect the harness connector at the B52A Heated Oxygen Sensor 1.

2. Test for 8-20 Ω between the B52A Heated Oxygen Sensor 1 ignition voltage circuit terminal 1 and the control circuit terminal 2.

3. If not within the specified range, replace the B52A Heated Oxygen Sensor 1.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


Heated Oxygen Sensor Replacement - Sensor 1 (LLU/A16LET)

Control Module References for ECM replacement, setup, and programming