GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2004 🢒 L300/LW300 🢒 DTC 🢒 DTC P0130 or P0150

Object Number: 1247850 Size: MF
Engine Controls Component Views
Engine Controls Schematics

Circuit Description

The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust stream more quickly and accurately than the switching style HO2S. The wide band sensor consists of an oxygen sensing cell, an oxygen pumping cell, and a heater. The exhaust gas sample passes through a diffusion gap between the sensing cell and the pumping cell. The engine control module (ECM) supplies a signal voltage to the HO2S and uses this voltage as a reference to the amount of oxygen in the exhaust system. An electronic circuit within the ECM controls the pump current through the oxygen pumping cell in order to maintain a constant signal voltage. The ECM monitors the voltage variation on the signal circuit and attempts to keep the voltage constant by increasing or decreasing the amount of current flow or reversing the direction of the current flow to the pumping cell. By measuring the direction and amount of current required to maintain the signal voltage, the ECM can determine the concentration of oxygen in the exhaust. The signal voltage is displayed as a lambda value. A lambda value of 1 is equal to a stoichiometric air fuel ratio of 14.7:1. Under normal operating conditions, the lambda value will remain around 1. When the system is lean, the oxygen level will be high and the lambda value will be high or more than 1. When the system is rich, the oxygen level is low and the lambda value will be low or less than 1. The ECM uses this information to maintain the proper air/fuel ratio. If the ECM detects a fault, DTC P0130 will set for bank 1 sensor 1 or DTC P0150 will set for bank 2 sensor 1.

Conditions for Running the DTC

DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0135, P0138, P0139, P0141, P0155, P0158, P0159, P0161 are not set.

Conditions for Setting the DTC

The ECM detects that one of the following relationships is true between the affected HO2S 1 and the HO2S 2 sensor on the same cylinder bank:

    • The affected HO2S 1 signal voltage is more than 4.81 volts for more than 2 seconds.
        OR
    • The affected HO2S 1 lambda value is between 0.995-1.005, while the HO2S 2 voltage is more than 0.850 volts or less than 0.103 volts.
        OR
    • The affected HO2S 1 lambda value is more than 1.2, and the HO2S 2 is more than 0.850 volts for 2-16 seconds.
        OR
    • The affected HO2S 1 lambda value is less than 0.8, and the HO2S 2 is less than 0.103 volts for 2-16 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.

Step

Action

Values

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?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Important: During idle or steady throttle conditions the lambda value will be very close to 1.000.

  1. Start the engine.
  2. Allow the engine to reach operating temperature. Refer to Scan Tool Data List .
  3. Operate the engine at 2,000 RPM for 1 minute.
  4. Observe the affected heated oxygen sensor (HO2S) lambda value.

Is the HO2S lambda value varying within the specified range?

0.900-1.100

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 90 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. Inspect the exhaust system for any leaks upstream from the affected oxygen sensor.
  3. Inspect for any exhaust leaks between the HO2S 1 and the HO2S 2.
  4. Repair the exhaust leak as necessary. Refer to Exhaust Leakage in Engine Exhaust.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 5

5
  1. Disconnect the connector for the HO2S that applies to this DTC.
  2. Visually/physically inspect the following items:
    3. • Ensure that the HO2S is securely installed.
    • Inspect for terminal corrosion or water intrusion.
    • Inspect the terminal tension at the HO2S connectors.
    • Inspect for damaged wiring.
  3. Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 6

6
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the HO2S lambda value with a scan tool.

Is the HO2S lambda value less than the specified value?

1.100

Go to Step 11

Go to Step 7

7

Measure the voltage from the HO2S output pump current circuit on the engine harness side to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage within the specified range?

4.8-5.1 V

Go to Step 8

Go to Step 9

8

Measure the voltage from the HO2S reference voltage circuit on the engine harness side to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage more than the specified value?

600 mV

Go to Step 15

Go to Step 16

9

Is the voltage less than the specified value?

375 mV

Go to Step 10

Go to Step 17

10

Measure the voltage from the HO2S reference voltage circuit on the engine harness side to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage more than the specified value?

6 V

Go to Step 19

Go to Step 20

11

Measure the voltage from the HO2S output pump current circuit on the engine harness side to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage within the specified range?

330-360 mV

Go to Step 12

Go to Step 14

12

Measure the voltage from the HO2S reference voltage circuit on the engine harness side to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the voltage within the specified range?

2.8-3.1 V

Go to Step 13

Go to Step 21

13
  1. Connect a 3-amp fused jumper wire between the HO2S low reference circuit on the engine harness side and ground.
  2. Observe the lambda value on the scan tool.

Is the lambda value less than the specified value?

3.500

Go to Step 18

Go to Step 22

14

Is the voltage less than the specified value?

330 mV

Go to Step 23

Go to Step 24

15

Important: The normal voltage on the HO2S low reference circuit is 2.4-2.6 volts.

Test the HO2S low reference 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 29

Go to Step 25

16

Test the following circuits for a short to ground:

    • The HO2S reference voltage circuit
    • The HO2S low reference circuit
        Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 25

17

Important: The normal voltage on the HO2S input pump current circuit and the HO2S output pump current circuit is 330-360 mV

Test the following circuits for a short to voltage:

    • The HO2S input pump current circuit
    • The HO2S output pump current circuit
        Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 25

18

Test the HO2S low reference circuit for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 25

19

Important: The normal voltage on the HO2S reference voltage circuit is 2.8-3.1 volts.

Test the HO2S reference voltage 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 29

Go to Step 25

20

Test the HO2S input pump current 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 29

Go to Step 25

21

Test the HO2S reference voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 25

22

Test the following circuits for a short to the HO2S heater low control circuit:

    • The HO2S input pump current circuit
    • The HO2S output pump current circuit
    • The HO2S low reference circuit
        Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 26

23

Test the HO2S output pump current circuit for the following conditions:

    • 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 29

Go to Step 25

24

Test the following HO2S circuits for a short to any other HO2S circuit:

    • The HO2S reference voltage circuit
    • The HO2S input pump current circuit
        Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 25

25

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 29

Go to Step 28

26
  1. The HO2S may be detecting a lean or rich exhaust condition. Inspect for one of the following conditions:
    2. • HO2S connector water intrusion
    • An exhaust leak between the HO2S and the engine--Refer to Exhaust Leakage in Engine Exhaust.
    • Vacuum leaks
    • Incorrect fuel pressure--Refer to Fuel System Diagnosis .
    • Fuel contamination- Water, even in small amounts, can be delivered to the fuel injectors. The water can cause a lean exhaust to be indicated. Excessive alcohol in the fuel can also cause this condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis for the proper procedure for inspecting for contaminants.
    • Lean fuel injectors--Refer to Fuel System Diagnosis .
    • An inaccurate mass air flow (MAF) sensor
    • HO2S element contamination
  2. Repair any of the above or similar engine conditions as necessary.

Did you find and correct the condition?

--

Go to Step 29

Go to Step 27

27

Replace the affected HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 .

Did you complete the replacement?

--

Go to Step 29

--

28

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 29

--

29
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 90 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 30

Go to Step 2

30

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