GM Service Manual Online
For 1990-2009 cars only

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 P0030: HO2S Heater Control Circuit Sensor 1

DTC P0036: HO2S Heater Control Circuit Sensor 2

DTC P0053: HO2S Heater Resistance Sensor 1

DTC P0054: HO2S Heater Resistance Sensor 2

DTC P0135: HO2S Heater Performance Sensor 1

DTC P0141: HO2S Heater Performance Sensor 2

Diagnostic Fault Information

HO2S Heater Sensor 1

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

HO2S Heater Voltage Supply

Opens fuse

P0030, P0036, P0053, P0054, P0102, P0134, P0135, P0140, P0141, P0443

P0053

P0030, P0053, P0135

--

P0135

HO2S Heater Low Control

P0030, P0036

P0053

P0030, P0053, P0135

P0030, P0135

P0135

HO2S Heater Sensor 2

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

HO2S Heater Voltage Supply

Opens fuse

P0030, P0036, P0053, P0054, P0102, P0134, P0135, P0140, P0141, P0443

P0054

P0036, P0054, P0141

--

P0141

HO2S Heater Low Control

P0030, P0036

P0054

P0036, P0054, P0141

P0036, P0141

P0141

Typical Scan Tool Data

HO2S Heater Sensor 1

Circuit

Normal Range

Short to Ground

Open

Short to Voltage

HO2S Heater Voltage Supply

Approximately 0.5-2.0 A

0.00 A

0.00 A

Approximately 0.5-2.0 A

HO2S Heater Voltage Supply

7-100%

7%

7%

7-100%

HO2S Heater Low Control

Approximately 0.5-2.0 A

0.00 A

0.00 A

0.00 A

HO2S Heater Low Control

7-100%

7%

7%

7%

HO2S Heater Sensor 2

Circuit

Normal Range

Short to Ground

Open

Short to Voltage

HO2S Heater Voltage Supply

Approximately 0.5-2.0 A

0.00 A

0.00 A

Approximately 0.5-2.0 A

HO2S Heater Voltage Supply

7-100%

7%

7%

7-100%

HO2S Heater Low Control

Approximately 0.5-2.0 A

0.00 A

0.00 A

0.00 A

HO2S Heater Low Control

7-100%

7%

7%

7%

Circuit/System Description

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the engine control module (ECM). The ECM uses pulse width modulation (PWM) to control the HO2S heater operation to maintain a specific HO2S operating temperature range.

Conditions for Running the DTC

P0030 and P0036

    • The engine is cranking or running.
    • The system voltage is between 10-18 volts.

P0053 and P0054

    • The ignition is OFF for more than 10 hours.
    • The ECT Sensor parameter is between -30 and +45°C (-22 and +133°F) at engine start-up.
    • The system voltage is between 10-18 volts.
    • This diagnostic runs one time per valid cold start when the above conditions are met.

P0135

    • DTCs P0030, P0053, P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0135, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
    • The system voltage is between 10-18 volts.
    • The scan tool special functions are not active.
    • The Engine Run Time parameter is more than 180 seconds.
    • The ECT Sensor parameter is at least 65°C (149°F).
    • The MAF Sensor parameter is between 5-30 g/s.
    • The Engine Speed parameter is between 500-3,000 RPM.
    • The above conditions have been met for more than 6 seconds.

P0141

    • DTCs P0036, P0054, P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
    • The system voltage is between 10-18 volts.
    • The scan tool special functions are not active.
    • The Engine Run Time parameter is at least 180 seconds.
    • The ECT parameter is at least 65°C (149°F).
    • The MAF Sensor parameter is between 5-30 g/s.
    • The Engine Speed parameter is between 500-3,000 RPM.
    • The above conditions have been met for more than 6 seconds.

Conditions for Setting the DTC

P0030 and P0036

    • The control module detects that the HO2S 1 heater control circuit status is incorrect for more than 2 seconds.
    • This diagnostic runs continuously.

P0053 and P0054

The control module detects that the HO2S 1 heater calculated resistance is not within an expected range at engine start-up for 1 second.

P0135

    • The HO2S heater current is less than 0.31 amp or more than 1.5 amps for more than 8 seconds, twice within a 1-minute test period.
    • The test is run 2 times per trip.

P0141

    • The HO2S heater current is less than 0.21 amp or more than 0.96 amp for more than 8 seconds, twice within a 1-minute test period.
    • The test is run 2 times per trip.

Action Taken When the DTC Sets

DTCs P0030, P0036, P0053, P0054, P0135, and P0141 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0030, P0036, P0053, P0054, P0135, and P0141 are Type B DTCs.

Diagnostic Aids

When using a high impedance, low current draw, test lamp to load the heater circuit, the test lamp flash may be dim, the scan tool Heater Command parameter may indicate 7 percent, and the Heater parameter may indicate 0 amps. This is a normal condition.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Heated Oxygen Sensor Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Output Controls

Circuit/System Verification

  1. Allow the engine to reach operating temperature.
  2. Engine running, verify the appropriate scan tool HO2S Heater parameter is varying between approximately 0.5-2.0 amps.

Circuit/System Testing

Important:  You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
  2. Ignition ON, verify that a test lamp illuminates between the appropriate HO2S heater voltage supply circuit terminal D and ground.
  3. If the test lamp does not illuminate, test the HO2S heater voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the HO2S heater voltage supply circuit fuse is open, test all components connected to the fuse and replace as necessary.
  4. Ignition ON, verify that a test lamp does not illuminate between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C.
  5. If the lamp illuminates, test the HO2S heater low control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  6. Engine running, leave the test lamp connected from the previous step. The lamp should flash or be ON steady.
  7. If the test lamp is not ON steady or flashing, test the HO2S heater low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

    Important: 

       • The output driver should detect a short to voltage and turn OFF. If a resistance fault is present the driver will remain ON and the scan tool will display more than 0.0 amp. Less than 10 ohms of resistance may set a DTC.
       • Performing this test may set additional DTCs.

  8. Ignition OFF, install a 30A fused jumper wire between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C.
  9. Engine running, verify the appropriate scan tool HO2S Heater parameter is less than 0.1 amp.
  10. If more than the specified range, test the HO2S heater voltage supply and HO2S heater low control circuits for more than 1 ohm of resistance. If the circuits test normal, replace the ECM.
  11. If the ECM and all circuits test normal, replace the appropriate HO2S.

Repair Instructions

Notice: Refer to Heated Oxygen Sensor Resistance Learn Reset Notice in the Preface section.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Heated Oxygen Sensor 1 Replacement
    •  Heated Oxygen Sensor 2 Replacement
    •  Control Module References for control module replacement, setup, and programming