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For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2000 🢒 Intrigue 🢒 Engine 🢒 Engine Controls - 3.5L 🢒 DTC P1133 HO2S Insufficient Switching Sensor 1

Refer to Engine Controls Schematics

Heated O2 Sensors


Object Number: 590136 Size: FS
Trans Solenoid, ABS, and O2 Sensor Fuses
Handling ESD Sensitive Parts Notice
Engine Controls Component Views
Powertrain Control Module Description
MAF, Secondary Air Injection Pump Bypass Solenoid, IAC and Secondary AIR Pump
A/C Pressure Switch, TPS, MAP, ECT and IAT
OBD II Symbol Description Notice
 .

Circuit Description

The powertrain control module (PCM) monitors the heated oxygen sensor (HO2S) activity for 100 seconds. During this test period, the PCM counts the number of times that the HO2S signal voltage crosses the rich to lean and lean to rich thresholds. If the PCM determines that the HO2S did not switch enough times, DTC P1133 will be set. A lean to rich switch is determined when the HO2S voltage changes from less than 300 mV to more than 600 mV. A rich to lean switch is determined when the HO2S voltage changes from more than 600 mV to less than 300 mV.

Conditions for Running the DTC
    • The following types of diagnostic trouble codes (DTCs) are not active:
      • Fuel trim
      • Fuel injector circuit
      • Misfire
      • Evaporative emission (EVAP) system
      • Exhaust gas recirculation (EGR) system
      • AIR system
      • Throttle position (TP) sensor
      • Intake air temperature (IAT) sensor
      • Manifold absolute pressure (MAP) sensor
      • Engine coolant temperature (ECT) sensor
      • Crankshaft position (CKP) sensor
      • Mass air flow (MAF) sensor
    • P0131, P0132 or P0135 not set
    • The system voltage is more than 9 volts.
    • The engine is running in closed loop
    • The engine is running for at least 3.3 minutes.
    • The ECT is more than 75°C (167°F)
    • The engine speed is between 1,000-3,000 RPM
    • The MAF is between 15-40 gm/s
    • The above conditions are stable for 3 seconds

Conditions for Setting the DTC
    • The above conditions are present for a 90 second monitoring period.
    • The PCM monitors fewer than 5 rich to lean and 5 lean to rich switches for HO2S 1.

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

Conditions for Clearing the MIL/DTC
    • The PCM turns the MIL OFF after 3 consecutive drive trips during which the diagnostic runs and passes.
    • A last test failed, or the current DTC, clears when the diagnostic runs and passes.
    • A History DTC clears after 40 consecutive warm-up cycles, if no other emission related diagnostic failures are reported.
    • Use a scan tool in order to clear the MIL diagnostic trouble code.
    • Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module Description , Clearing Diagnostic Trouble Codes.

Diagnostic Aids

Notice: Use the connector test adapter kit J 35616-A for any test that requires probing the following items:

   • The PCM harness connectors
   • The electrical center fuse/relay cavities
   • The component terminals
   • The component harness connector
Using this kit will prevent damage caused by the improper probing of connector terminals.

A malfunction in the HO2S heater ignition feed or ground circuit may cause the DTC to set. Check HO2S heater circuitry for intermittent malfunctions or poor connections. If connections and wiring are OK and the DTC continues to set, the HO2S may be at fault.

Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to set occurs. This may assist in diagnosing the condition.

If the problem is intermittent, refer to Intermittent Conditions .

Test Description

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

  1. This step checks for correct sensor activity. When in Closed Loop fuel control, the HO2S voltage should rapidly swing above and below the bias voltage.

    2.

  2. This step checks the PCM and the high and low circuits between the PCM and the HO2S connector for correct operation.

    3.

  3. This step checks for correct HO2S heater circuit operation up to the HO2S connector.

    4.

  4. This step checks for correct circuit resistance between the HO2S low circuit and the PCM ground.

    5.

  5. This step checks for proper circuit resistance between the HO2S low circuit and the PCM ground with a COLD sensor. A loose HO2S or faulty thread to exhaust electrical contact will cause higher resistance when the HO2S is cold. Although 500 ohms is allowed, typical resistance should be less than 50 ohms.

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Clear the DTCs using a scan tool.
  2. Reset the fuel trim values.
  3. Start and idle the engine until normal operating temperature is reached.
  4. Using a scan tool, monitor the HO2S voltage for the sensor that applies to this DTC.

Is the HO2S voltage fixed within the voltage range specified?

351-551 mV

Go to Step 4

Go to Step 3

3
  1. The condition that set this DTC is not present. This DTC may have been set by one of the following conditions:
    2. • HO2S connector water intrusion
    • An intermittently open HO2S high signal circuit
    • An intermittently open HO2S low circuit
    • An HO2S low circuit with high resistance to ground
    • PCM ground circuits with high resistance to ground
    • An inoperative HO2S heater
    • Faulty HO2S or PCM connector terminal contact
    • An exhaust system leak, typically within 12 inches up-stream of the HO2S
    • A defective HO2S
  2. Repair any of the above conditions as necessary.

Was a condition found and repaired?

--

Go to Step 17

Go to Dignostic Aids

4

  1. Turn the ignition OFF.
  2. Disconnect the HO2S connector for the sensor that applies to this DTC.
  3. Jumper the HO2S low circuit to a known good ground.
  4. Jumper the HO2S high signal circuit to a known good ground.
  5. Turn the ignition On leaving the engine OFF.
  6. Using a scan tool, monitor the HO2S voltage for the sensor that applies to this DTC.

Is the HO2S voltage less than the value specified?

20 mV

Go to Step 7

Go to Step 5

5
  1. Turn the ignition OFF.
  2. Remove the jumpers from the HO2S terminals.
  3. Disconnect the PCM connector containing the HO2S high and low circuits.
  4. Using a digital multimeter (DMM), first measure the continuity of the HO2S high signal circuit. Then measure the continuity of the HO2S low circuit between the PCM connector terminal and the engine harness side of the HO2S connector terminal.

Is the individual resistance of both circuits less than the specified value?

5 ohms

Go to Step 6

Go to Step 9

6
  1. Check for correct PCM connector terminal contact.
  2. Repair PCM terminals as necessary. Refer to Repairing Connector Terminals in Wiring Systems.

Was a PCM terminal repair made?

--

Go to Step 17

Go to Step 16

7

  1. Remove the jumpers from the HO2S terminals.
  2. Connect a test lamp between the HO2S heater ignition feed and the engine harness side of the heater ground circuit terminals.
  3. Ensure that the ignition is ON while the engine is OFF.

Is the test lamp illuminated?

--

Go to Step 8

Go to Step 10

8

  1. Turn the ignition OFF.
  2. Reconnect the HO2S connector.
  3. Disconnect the PCM connector containing the HO2S low circuit and the PCM connector containing the PCM ground circuits.
  4. Using the DMM, measure the resistance between the HO2S low circuit terminal and one of the PCM ground circuit terminals.

Is the resistance measured less than the value specified?

500 ohms

Go to Step 12

Go to Step 11

9

Repair the circuit that measured high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

--

Go to Step 17

--

10

Repair the HO2S heater ignition or ground circuit. Refer to Wiring Repairs in Wiring Systems. Probable causes of the problem include the following:

    • An open circuit
    • High circuit resistance
    • A faulty ground connection
    • A blown heater fuse -- If this is the cause, other DTCs should also be set.

Is the action complete?

--

Go to Step 17

--

11

Repair the high resistance between the HO2S low circuit and the PCM ground circuit. Refer to Wiring Repairs in Wiring Systems. Probable causes of the problem include the following:

    • Poor HO2S connector terminal contact
    • An open sensor harness low circuit -- requires HO2S replacement.
    • A sensor harness low circuit with high resistance -- This requires HO2S replacement. Refer to Heated Oxygen Sensor Replacement .
    • A faulty PCM ground connection
    • High PCM ground circuit resistance
    • An ungrounded exhaust system

Is the action complete?

--

Go to Step 17

--

12
  1. Check for exhaust system leaks upstream of the suspect HO2S.

    2. The leak may be very small and will typically will be within 12 inches of the suspect HO2S.

  2. Repair the exhaust as necessary.

Was an exhaust system repair made?

--

Go to Step 17

Go to Step 13

13

  1. Allow the engine to cool to ambient temperature.
  2. Using the DMM, again measure the resistance between the HO2S low circuit terminal and a PCM ground circuit terminal.

Is the resistance less than the value specified?

500 ohms

Go to Step 15

Go to Step 14

14
  1. Remove the HO2S from the exhaust.
  2. Clean the HO2S mounting threads.
  3. Apply anti-seize compound 5613695 or an equivalent to the sensor threads.
  4. Tighten the HO2S to the proper torque. Refer to Heated Oxygen Sensor Replacement .
  5. Using the DMM, again measure the resistance between the HO2S low circuit terminal and a PCM ground circuit terminal.

Is the resistance less than the value specified?

500 ohms

Go to Step 17

Go to Step 15

15

Replace the HO2S. Refer to Heated Oxygen Sensor Replacement .

Is the action complete?

--

Go to Step 17

--

16

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 17

--

17
  1. Clear the DTCs with the scan tool.
  2. Turn the key to the OFF position and wait 15 seconds.
  3. Operate the vehicle within the conditions that are required for this diagnostic to run. Refer to the Conditions for Running the DTC.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 18

Go to Step 2

18

Review the Captured Info using the scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to the applicable DTC table

System OK