GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Epica 🢒 Engine 🢒 Engine Controls - 2.5L (LBK) 🢒 DTC P0032, P0038, P0052, or P0058

Circuit Description

The 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 the ignition 1 voltage circuit through a fuse. Ground is provided to the heater on the control circuit by a low side driver within the control module. The control module monitors the control circuit of the heater to determine if a failure is present.

If the ECM detects a short to voltage on the control circuit of the H02S heater, a DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTCs:

    • DTC P0032 HO2S Heater Control Circuit High Voltage Bank 1 Sensor 1
    • DTC P0038 HO2S Heater Control Circuit High Voltage Bank 1 Sensor 2
    • DTC P0052 HO2S Heater Control Circuit High Voltage Bank 2 Sensor 1
    • DTC P0058 HO2S Heater Control Circuit High Voltage Bank 2 Sensor 2

Conditions for Running the DTC
    • The engine is operating.
    • The commanded state of the H02S heater is between 2-98 percent.
    • The DTCs run continuously once the above conditions are met.

Conditions for Setting the DTC

The ECM detects a short to voltage on the control circuit of the H02S heater for more than 25 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step is testing the heater control circuit for a short to voltage.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Start the engine.
  2. Allow the engine to reach the normal operating temperature.

    3. Important: It may take up to 8 minutes for this DTC to set.

  3. Observe the DTC Information with a scan tool.

Did DTC P0032, P0038, P0052, or P0058 fail this ignition?

Go to Step 4

Go to Step 3

3

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 4

Go to Intermittent Conditions

4

  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the affected heated oxygen sensor (HO2S). For the H02S location, refer to Engine Controls Component Views .
  3. Start the engine.
  4. Connect a test lamp between the control circuit of the HO2S heater and battery positive voltage.

Does the test lamp illuminate?

Go to Step 6

Go to Step 5

5

Test the control circuit of the HO2S heater for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

6

Test for shorted terminals and poor connections at the HO2S. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 8

7

Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the appropriate HO2S.

Did you complete the replacement?

Go to Step 10

--

9

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 10

--

10
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 11

11

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK