GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2002 🢒 Sunfire 🢒 Engine 🢒 Engine Controls - 2.2L (L61) 🢒 DTC P0133

Circuit 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 of the exhaust stream. When the vehicle is first started, the powertrain control module (PCM) operates in an Open Loop mode, ignoring the HO2S signal voltage when calculating the air-to-fuel ratio. The PCM supplies the HO2S with a reference, or bias, voltage of 450 mV. The HO2S generates a voltage within a range of 0-1,000 mV, that fluctuates above and below bias voltage once in Closed Loop. High HO2S voltage output indicates a rich fuel mixture. Low HO2S voltage output indicates a lean mixture. A heating element inside the HO2S reduces the time required for the sensor to reach operating temperature, and provides an accurate voltage signal.

The PCM monitors the rich-to-lean and lean-to-rich HO2S switching activity. This DTC will set if the HO2S voltage response time is higher than a calibrated threshold response.

Conditions for Running the DTC
    • DTCs P0105, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0201-P0204, P0300, P0301-P0304, P0336, P0440, P0446, P0452, P0453, P0506, P0507, P0601, P0602, P1441, or P1621 are not set.
    • The engine coolant temperature (ECT) is more than 70°C (158°F).
    • The battery voltage is more than 10 volts.
    • The fuel level is more than 10 percent.
    • The engine run time is more than 200 seconds.
    • The engine speed is between 1,750-3,500 RPM.
    • The engine is operating in Closed Loop.
    • The throttle position (TP) angle is between 10-30 percent.
    • The evaporative emissions control system is commanded open for more than 36 percent.
    • The purge learned memory is more than approximately 0.78.
    • The diagnostic completes when 30 seconds of accumulated time has been spent in the above conditions.
    • The above conditions are met for more than 2 seconds.

Conditions for Setting the DTC
    • The average HO2S 1 response times are more than 875 mS for rich-to-lean sweeps, or 600 mS for lean-to-rich sweeps.
        OR
    • Sum of rich to lean and lean to rich is more than 875 mS.

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 numbers below refer to the step numbers on the diagnostic table.

  1. When the system is operating correctly, the HO2S 1 voltage should toggle above and below the specified values. You may need to operate the vehicle within the Freeze Frame conditions and Conditions for Setting the DTC in order to duplicate the malfunction that was detected by the PCM.

    2.

  2. The specified value is what is measured on a correctly operating system.

    3.

  3. The specified value is what is measured on a correctly operating system.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Important: If any other DTCs are set except for HO2S DTCs, refer to the other DTCs first before proceeding with this table.

  1. Operate the engine at normal operating temperature.
  2. Operate the engine above 1,200 RPM for 2 minutes.
  3. With a scan tool, observe the HO2S 1 voltage parameter.

Does the scan tool indicate that the HO2S  1 voltage is varying above and below the specified values?

350-550 mV

Go to Step 3

Go to Step 4

3
  1. Observe the Freeze Frame/Failure Records data 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 as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.

Does the scan tool indicate that this DTC failed this ignition?

--

Go to Step 4

Go to Intermittent Conditions

4

  1. Turn OFF the ignition.
  2. Disconnect the HO2S 1.
  3. Turn ON the ignition, with engine OFF.
  4. Using a DMM, measure the voltage of the HO2S 1 high signal circuit on the PCM side to a good ground.

Does the voltage measure within the specified value?

350-550 mV

Go to Step 5

Go to Step 9

5

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the HO2S 1 high signal circuit and the HO2S 1 low signal circuit.
  3. Turn ON the ignition.
  4. Use a scan tool in order to monitor the HO2S 1 voltage for the sensor that applies to this DTC.

Does the scan tool indicate that the HO2S 1 voltage is less than the specified value?

20 mV

Go to Step 6

Go to Step 10

6
  1. Turn OFF the ignition.
  2. Remove the 3-amp fused jumper wire.
  3. Connect a test lamp between the ignition 1 voltage circuit and a good ground. Do not use the HO2S 1 heater low control.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 11

7
  1. Connect a test lamp between the ignition 1 voltage circuit and the HO2S 1 heater low control circuit.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the HO2S 1 heater ON and OFF .

Does the test lamp turn ON and OFF with each command?

--

Go to Step 14

Go to Step 8

8

Does the test lamp remain illuminated with each command?

--

Go to Step 12

Go to Step 13

9

Test the HO2S 1 high signal circuit for the following conditions:

    • Open
    • High Resistance
    • Short to Ground
    • Short to Voltage

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 16

10

Test the HO2S 1 low signal circuit for an open, a high resistance, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 16

11
  1. Test the ignition 1 voltage circuit for an open, high resistance, or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. Replace the ERLS fuse if necessary.

Did you find and correct the condition?

--

Go to Step 19

Go to Intermittent Conditions

12

Test the HO2S 1 low control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 16

13

Test the HO2S 1 low control circuit for an open, a high resistance, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 16

14

Important: Before replacing the HO2S, check and remove any source of contamination.

Inspect for the following conditions:

    • The use of incorrect silicon RTV sealant
    • Fuel contamination
    • An exhaust leak
         Refer to Exhaust Leakage in Engine Exhaust.
    • The HO2S is installed correctly
    • Damaged wiring
         Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 15

15

Inspect for poor connections at the harness connector of the HO2S 1. 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 19

Go to Step 17

16

Inspect for poor connections at the harness connector of the PCM. 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 19

Go to Step 18

17

Replace the HO2S 1. Refer to Heated Oxygen Sensor Replacement .

Did you complete the replacement?

--

Go to Step 19

--

18

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 19

--

19
  1. Use the scan tool in order to clear the DTCs .
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

Go to Step 20

Go to Step 2

20

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK