P0139
DTC P0133 or P0139
DTC Descriptors
DTC P0133
- HO2S Slow Response Sensor 1
DTC P0139
- HO2S Slow Response Sensor 2
Diagnostic Fault Information
Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit Description
The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450 mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.
The HO2S utilizes the following circuits:
* A signal circuit
* A low reference circuit
* An ignition 1 voltage circuit
* A heater control circuit
Conditions for Running the DTC
P0133
* The calculated airflow into the engine is between 9-40 g/s.
* The engine speed is between 1,500-4,300 RPM.
* The engine coolant temperature is greater than 70°C (158°F).
* The ignition 1 voltage is greater than 10 volts.
* The fuel system is in Closed Loop.
* The engine has been operating for 60 seconds.
* The vehicle is not decelerating.
* The DTC runs continuously when the above conditions are met for 2 seconds.
P0139
* This DTC is ran after the Idle Catalyst Monitor Diagnostic (ICMD).
* DTCs P0030, P0036, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0131, P0132, P0133, P0137, P0138, P0140, P0171, P0172, P0300, P0335, P0336, P0337, P0341, P0342, P0400-P0406, P0501, P0510 and U0101 are not set.
* Before the ECM performs the idle test, the vehicle must be driven under the following conditions:
- The calculated air flow into the engine is more than 7.8 g/s for more than 16 seconds for a manual transmission.
- The calculated air flow into the engine is more than 11 g/s for more than 11 seconds for an automatic transmission.
* The engine has been running for more than 9.5 minutes.
* The throttle angle is less than 1.5 percent.
* The evaporative emission (EVAP) purge concentration is learned.
* The long term fuel trim is learned.
* The air flow into the engine is between 2.25-6.5 g/s.
* The engine has been idling less than 60 seconds.
* The vehicle speed is less than 3 km/h (2 mph).
* The engine coolant temperature (ECT) is between 70-109°C (160-228°F).
* The intake air temperature (IAT) is between -7 and +105°C (+19 and +221°F).
* The barometric pressure (BARO) is more than 72 kPa.
* The catalytic converter (TWC) calculated temperature is between 300-900°C (662-1652°F).
* The vehicle is operating in Closed Loop.
* Torque fuel reduction is not active.
* The transmission is not in P/N (automatic transmission only).
This diagnostic attempts one test during each valid idle period once the above conditions have been met. This diagnostic attempts up to 12 tests during each drive cycle.
Conditions for Setting the DTC
P0133
The ECM detects that the HO2S 1 rich-to-lean or lean-to-rich counts are less than 60 counts.
P0139
The ECM detects that the HO2S 2 has failed to respond during the ICMD then after for 25 seconds.
Action Taken when the DTC Sets
DTC P0133 and P0139 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTC P0133 and P0139 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics Electrical Diagrams
Connector End View Reference
* Engine Control Module (ECM) Connector End Views Engine Control Module (ECM) Connector End Views
* Engine Controls Connector End Views Engine Controls Connector End Views
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Diagnostic Trouble Code (DTC) Type Definitions Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
* Scan Tool Data List Scan Tool Data List
* Scan Tool Data Definitions Scan Tool Data Definitions
* Scan Tool Output Controls Scan Tool Output Controls
Circuit/System Verification
1. Verify that other DTCs are not set.
• If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Operate the vehicle within the conditions for running the DTC. DTC P0133 or P0139 should not set.
3. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.
Circuit/System Testing
1. Verify that none of the following conditions exist:
* Lean or rich fuel injectors-Refer to Fuel Injector Balance Test with Special Tool Fuel Injector Balance Test with Special Tool.
* Water intrusion in the HO2S harness connector
* HO2S wiring harness damage
* Incorrect RTV sealant
* Low or high fuel system pressure-Refer to Fuel System Diagnosis Fuel System Diagnosis.
* Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool) Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)Alcohol/Contaminants-in-Fuel Diagnosis (w/Special tool) Alcohol/Contaminants-in-Fuel Diagnosis (w/Special tool).
* Fuel saturation of the evaporative emission (EVAP) canister
* Exhaust leaks near the HO2S
* Engine vacuum leaks
* Engine oil consumption-Refer to Oil Consumption Diagnosis Oil Consumption Diagnosis.
* Engine coolant consumption-Refer to Loss of Coolant Loss of Coolant
• If you find any of the above conditions, repair as necessary.
2. If all conditions test normal, replace the appropriate HO2S.
Repair Instructions
Important: Always perform the Diagnostic Repair Verification Diagnostic Repair Verification after completing the diagnostic procedure.
* Heated Oxygen Sensor Replacement - Position 1 Heated Oxygen Sensor Replacement - Position 1
* Heated Oxygen Sensor Replacement - Position 2 Heated Oxygen Sensor Replacement - Position 2
* Control Module References Control Module References for engine control module replacement, setup, and programming