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For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2003 🢒 ION 🢒 DTC 🢒 DTC P1133

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 in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The engine control module (ECM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started the ECM operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream, low HO2S voltage indicates a lean exhaust stream. This diagnostic will only run once per ignition cycle. The ECM monitors the number of rich-to-lean and lean-to-rich transitions. If the ECM detects that the number of transitions were less than a specified value, DTC P1133 will set.

Conditions for Running the DTC
    • DTCs P0037, P0038, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0130, P0133, P0137, P0138, P0140, P0171, P0172, P0300, P0336, P0340, P0341, P0455, P0500, P0601, P0602, P0606, P0641, P0722, P0723, P1134 are not set.
    • The Air Flow parameter is between 7-25 g/s.
    • The Engine Speed parameter is between 1,500-3,200 RPM.
    • The Loop Status parameter is closed.
    • The above conditions are met for 100 seconds.

Conditions for Setting the DTC

The ECM detects that the HO2S 1 Lean/Rich or the Rich/Lean transitions are less than a calibrated value.

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.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics

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

1

Did you perform the Diagnostic System Check-Engine Controls?

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Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Start the engine.
  2. Allow the engine to reach operating temperature. Refer to Scan Tool Data List .
  3. Operate the engine at 1,500 RPM for 30 seconds.
  4. Observe the HO2S 1 voltage parameter with a scan tool.

Is the HO2S 1 voltage parameter varying above and below the specified range?

300-600 mV

Go to Step 3

Go to Step 4

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 HO2S 1.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the HO2S 1 voltage parameter with a scan tool.

Is the HO2S 1 voltage parameter less than the specified value?

100 mV

Go to Step 6

Go to Step 5

5

Is the HO2S 1 voltage parameter more than the specified value?

800 mV

Go to Step 7

Go to Step 9

6

Test the HO2S 1 high signal 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 17

Go to Step 8

7

Important: The sensor may be damaged if the circuit is shorted to a voltage source.

Test the HO2S 1 high signal circuit 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 17

Go to Step 16

8

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

Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

9
  1. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S 1 harness connector on the engine harness side and a good ground.
  2. Observe the HO2S 1 voltage parameter with a scan tool.

Is the HO2S 1 voltage parameter less than the specified value?

100 mV

Go to Step 10

Go to Step 12

10
  1. Remove the jumper wire from the previous step.
  2. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S 1 harness connector on the engine harness side and the low signal circuit of the HO2S 1 harness connector on the engine harness side.
  3. Observe the HO2S 1 voltage parameter with a scan tool.

Is the HO2S 1 voltage parameter less than the specified value?

100 mV

Go to Step 13

Go to Step 11

11

Test the HO2S 1 low signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

12

Test the HO2S 1 high signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

13

Test for an intermittent and for a poor connection at 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 17

Go to Step 15

14

Test for an intermittent and for a poor connection at the 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 17

Go to Step 16

15

Notice: Refer to Silicon Contamination of Heated Oxygen Sensors Notice in the Preface section.

Important: The HO2S may be damaged due to contamination. Prior to replacing the HO2S inspect for the following sources of contamination:

    • A silicon contaminated HO2S
    • Fuel contamination--Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Engine oil consumption--Refer to Oil Consumption Diagnosis in Engine Mechanical.
    • Engine coolant consumption--Refer to Loss of Coolant in Engine Cooling.

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

Did you complete the replacement?

--

Go to Step 17

--

16

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 17

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17
  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 18

18

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