GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Optra 🢒 Engine 🢒 Engine Controls - 2.0L (L34 GMDAT) 🢒 DTC P0141

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 low control circuit by a low side driver within the control module. The control module monitors the current draw of the heater to determine if a failure is present.

If the engine control module (ECM) detects that the HO2S 2 heater current is below a specified value, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0141 HO2S Heater Performance Sensor 2

Conditions for Running the DTC
    • The engine run time is more than 60 seconds.
    • The ignition 1 voltage is more than 10 volts.
    • DTC P0141 runs continuously once the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the HO2S 2 heater current is less than 0.1 amp for 13 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 ground.

    2.

  2. This step is testing the heater control circuit for an open or for a short to voltage.

    3.

  3. This step is testing the heater control circuit for high resistance. If the voltage is more than the specified value, test the circuit for high resistance.

Step

Action

Values

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. Operate the engine above 1,200 RPM for 30 seconds and then allow the engine to idle.

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

  4. Observe the DTC Information with a scan tool.

Did DTC P0141 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. Disconnect the heated oxygen sensor (HO2S) 2.
  2. Turn ON the ignition, with the engine OFF.
  3. Probe the ignition 1 voltage circuit of the HO2S 2 with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 13

5
  1. Turn OFF the ignition.
  2. Disconnect the fuse that supplies ignition 1 voltage to the HO2S 2 heater.
  3. Measure the resistance of the ignition 1 voltage circuit of the HO2S 2 heater from the fuse terminal to the harness connector terminal of the HO2S 2 heater.

Is the resistance less than the specified value?

3 ohms

Go to Step 6

Go to Step 13

6

  1. Turn OFF the ignition.
  2. Connect a test lamp between the control circuit of the HO2S 2 heater and battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 7

7

  1. Turn ON the ignition, with the engine OFF.
  2. Connect a test lamp between the control circuit of the HO2S 2 heater and battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 9

8

  1. Turn ON the ignition, with the engine OFF.

    2. Important: Use the J 35616-200 Test Lamp Kit for this test. If the J 35616-200 is not available, use a test lamp that measures between 25-30 ohms.

  2. Probe the control circuit of the HO2S 2 heater with a test lamp connected to battery positive voltage.
  3. Measure the voltage from the probe of the test lamp to a good ground.

Is the voltage less than the specified value?

0.3 V

Go to Step 11

Go to Step 10

9

Test the control circuit of the HO2S 2 heater for one of the following conditions:

    • A short to voltage
    • An open
    • A short to ground

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

10

Test the control circuit of the HO2S 2 heater for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

11

Test for an intermittent and poor connection at the HO2S 2. 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 16

Go to Step 14

12

Test for an intermittent and poor connection 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 16

Go to Step 15

13
  1. Repair the ignition 1 voltage circuit of the HO2S 2 heater for one of the following conditions:
    2. • An open
    • A short to ground
    • High resistance
  2. Replace the fuse, as necessary.

Did you complete the repair?

--

Go to Step 16

--

14

Replace the HO2S 2. Refer to Heated Oxygen Sensor 2 Replacement .

Did you complete the replacement?

--

Go to Step 16

--

15

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 16

--

16
  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 17

17

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