Buick Regal: DTC P0137, P0138, P013A, P013B, P013E, P013F, P2270, or P2271

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0137

HO2S Circuit Low Voltage Sensor 2

DTC P0138

HO2S Circuit High Voltage Sensor 2

DTC P013A

HO2S Slow Response Rich to Lean Sensor 2

DTC P013B

HO2S Slow Response Lean to Rich Sensor 2

DTC P013E

HO2S Delayed Response Rich to Lean Sensor 2

DTC P013F

HO2S Delayed Response Lean to Rich Sensor 2

DTC P2270

HO2S Signal Stuck Lean Sensor 2

DTC P2271

HO2S Signal Stuck Rich Sensor 2

Diagnostic Fault Information

Typical Scan Tool Data

HO2S Sensor 2

Circuit/System Description

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S 2 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. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0 - 1, 000 mV. 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 toward 1, 000 mV indicates a rich fuel mixture. An HO2S voltage that decreases 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.

Conditions for Running the DTC

P0137

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
• The Ignition voltage is between 10 - 32 V.
• The fuel system is operating in Closed Loop.
• Device controls are not active.
• The fuel level is greater than 10 %.
• Ethanol content is less than 87 %.
• Decel fuel cut-off is not active.
• The DTCs run continuously when the above conditions are met for 5 s.

P0138

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
• The Ignition voltage is between 10 - 32 V.
• Ignition is OFF for greater than 8 h.
• The fuel system is operating in Closed Loop.
• Ethanol content is less than 87 %.
• The fuel level is greater than 10 %.
• The engine run time is greater than 30 s.
• The engine is not in Power Enrichment.
• The DTCs run continuously after an initial delay of 3 min when the above conditions are met for 5 s.

P013A or P013E

• Before the ECM can report DTC P013A, or P013C failed, DTCs P013E, P014A, P2270, and P2272 must run and pass.
• Before the ECM can report DTC P013E, or P014A failed, DTCs P2270 and P2272 must run and pass.
• DTCs P0030, P0036, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0120, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0171, P0172, P0201 - P0208, P0220, P0222, P0223, P0300 - P0308, P0442, P0443, P0446, P0449, P0455, P0496, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271 are not set.
• The Ignition voltage is between 10 - 32 V.
• The engine is OFF for greater 8 h.
• The learned heater resistance is valid.
• The fuel level is greater than 10%.
• After the above conditions are met decel fuel cut-off continues without driver initiated pedal input.
• The DTCs run once per ignition cycle, during decel fuel cut-off (DFCO), when the above conditions are met.

P013B or P013F

• Before the ECM can report DTC P013B, or P013D failed, DTCs P013A, P013C, P013E, P013F, P014A, P014B, P2270, P2271, P2272, and P2273 must run and pass.
• Before the ECM can report DTC P013F, or P014B failed, DTCs P013A, P013C, P013E, P014A, P2270, P2271, P2272, and P2273 must run and pass.
• DTCs P0030, P0036, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0120, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0171, P0172, P0201 - P0208, P0220, P0222, P0223, P0300 - P0308, P0442, P0443, P0446, P0449, P0455, P0496, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271 are not set.
• The Ignition voltage is between 10 - 32 V.
• The engine is OFF for greater 8 h.
• The learned heater resistance is valid.
• The fuel level is greater than 10%.
• After the above conditions are met, fuel enrich mode is continued.
• The DTCs run once per ignition cycle when the above conditions are met.

P2270

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P013A, P013B, P013E, P013F, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0411, P0412, P0418, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271 are not set.
• The system voltage is between 10 - 32 V.
• The engine is OFF for greater 8 h.
• The fuel level is greater than 10%.
• The pedal position is less than 4%.
• The engine speed is between 950 - 2, 950 RPM.
• The engine airflow is between 3 - 12 g/s.
• The vehicle speed is between 66 - 124 km/h (41 - 77 mph).
• The fuel state is in Closed Loop.
• The evaporative emission (EVAP) diagnostics are not in control of purge.
• The HO2S heaters are ON for more than 80 s.

  The predicted catalytic converter temperature is between 500 - 850ºC (932 - 1, 562ºF).

• This DTC runs once per trip when all of the above conditions have been met for 1 s.

P2271

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P013A, P013B, P013E, P013F, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0411, P0412, P0418, P1174, P1516, P2101, P2119, P2135, P2176, P2270 are not set.
• The system voltage is between 10 - 32 V.
• The engine is OFF for greater 8 h.
• The fuel level is greater than 10%.
• The fueling state is in Closed Loop.
• DTCs P013A, P013E, and P2270 have run and passed.
• Decel fuel cut-off is active.
• The accelerator pedal position is stable.
• This DTC runs once per trip when the above conditions are met for 3 s.

Conditions for Setting the DTC

P0137

The engine control module detects that the heated oxygen sensor voltage is less than 50 mV and the circuit is shorted to ground for greater than 50 s.

P0138

The engine control module detects that the heated oxygen sensor voltage is greater than 1, 050 mV and the circuit is shorted to voltage for greater than 13 s.

P013A

The engine control module detects that the accumulated mass air flow monitored during rich-to-lean transitions between 450 - 150 mV is greater than 36 grams.

P013B

The engine control module detects that the accumulated mass air flow monitored during lean-to-rich transitions between 300 - 600 mV is greater than 88 grams.

P013E

The engine control module detects an initial delayed response to a change from rich to lean such that the heated oxygen sensor voltage has not decreased to 450 mV within a calibrated value of accumulated air flow.

P013F

The engine control module detects an initial delayed response to a change from lean to rich such that the heated oxygen sensor voltage has not increased above 350 mV within a calibrated value of accumulated air flow.

P2270

The engine control module does not detect a heated oxygen sensor voltage greater than 825 mV before accumulated mass air flow exceeds a calibrated value.

P2271

The engine control module does not detect an heated oxygen sensor voltage less than 100 mV before accumulated mass air flow exceeds a calibrated value.

Action Taken When the DTC Sets

• DTCs P0137, P0138, P013E, P013F, P2270, and P2271 are Type B DTCs.
• DTCs P013A and P013B are Type A DTCs.

Conditions for Clearing the MIL/DTC

• DTCs P0137, P0138, P013E, P013F, P2270, and P2271 are Type B DTCs.
• DTCs P013A and P013B are Type A DTCs.

Reference Information

Schematic Reference

Engine Controls Wiring Schematics (LTG)

Connector End View Reference

Component Connector End View Index

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify no HO2S heater DTCs are set.

• If a DTC is set.

Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

• Go to next step: If a DTC is not set.

3. Engine running.

4. Verify the scan tool HO2S 1 or 2 parameters are between 50 - 1, 050 mV.

• If not between 50 - 1, 050 mV.

Refer to Circuit/System Testing.

• Go to next step: If between 50 - 1, 050 mV.

5. 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 data.

6. Verify the DTC does not set.

• If the DTC sets.

Refer to Circuit/System Testing.

• Go to next step: If the DTC does not set.

7. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the appropriate B52 Heated Oxygen Sensor harness connector. It may take up to 2 minutes for all vehicle systems to power down. Ignition ON.

2. Test for 1.7 - 3.0 V between the high signal circuit terminal 4 and ground.

• If less than 1.7 V

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the high signal circuit terminal 4 and ground.
   • If less than infinite resistance repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in the high signal circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K20 Engine Control Module.

• If greater than 3.0 V

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the high signal circuit terminal 4 and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K20 Engine Control Module.

• Go to next step: If between 1.7 - 3.0 V

3. Verify the scan tool HO2S 2 parameter is between 1.7 - 2.1 V.

• If less than 1.7 V

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the low signal circuit terminal 3 and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance, replace the K20 Engine Control Module.

• Go to next step: If between 1.7 - 2.1 V

4. Connect a 3 A fused jumper wire between the high signal circuit terminal 4 and the low signal circuit terminal 3.

NOTE: The low signal circuit is tied to a pull-up circuit within the engine control module. A voltage of 0.0 - 1.10 V on the low signal circuit is normal.

5. Verify the scan tool HO2S 1 or 2 parameter displays 0.0 V.

• If greater than 0.0 V

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 2 Ω in the low signal circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • Go to next step: If less than 2 Ω
3. Test for less than 1 V between the low signal circuit terminal 3 and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K20 Engine Control Module.

• Go to next step: If 0.0 V

6. Verify none of the conditions listed below exist:

• Water intrusion in the B52 Heated Oxygen Sensor harness connector
• Low or high fuel system pressure - Refer to Fuel System Diagnosis.
• Fuel that is contaminated - Refer to Alcohol/Contaminants-in-Fuel Diagnosis.
• Fuel saturation of the evaporative emission (EVAP) canister
• Exhaust leaks
• Engine vacuum leaks
• Engine oil consumption - Refer to Oil Consumption Diagnosis.
• Engine coolant consumption - Refer to Loss of Coolant.
• If any of the conditions exist

Repair as necessary.

• Go to next step: If none of the conditions exist

Go to next step: Test or replace the B52 Heated Oxygen Sensor

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Heated Oxygen Sensor Replacement - Sensor 1
• Heated Oxygen Sensor Replacement - Sensor 2
• Perform the scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing an HO2S.
• Control Module References for ECM replacement, programming and setup

READ NEXT: