For 1990-2009 cars

### 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 provide an overview of each diagnostic category.

### DTC Descriptor

DTC P0133 00: HO2S Slow Response Sensor 1
DTC P0134 00: HO2S Circuit Insufficient Activity Sensor 1
DTC P013A 00: HO2S Slow Response Rich to Lean Sensor 2
DTC P013B 00: HO2S Slow Response Lean to Rich Sensor 2
DTC P013E 00: HO2S Delayed Response Rich to Lean Sensor 2
DTC P013F 00: HO2S Delayed Response Lean to Rich Sensor 2
DTC P0140 00: HO2S Circuit Insufficient Activity Sensor 2
DTC P1133 00: HO2S Insufficient Switching Sensor 1
DTC P2270 00: HO2S Signal Stuck Lean Sensor 2
DTC P2271 00: HO2S Signal Stuck Rich Sensor 2
DTC P2A00 00: HO2S Circuit Closed Loop Performance Sensor 1

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
HO2S high signal | P0131 00, P0132 00, P0137 00, P0140 00, P1133 00, P2A00 00 | P0131 00, P0132 00, P0133 00, P0134 00, P0137 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P1133 00, P2A00 00 | P0132 00, P0134 00, P0138 00, P0140 00, P1133 00, P2A00 00 | P0133 00, P0134 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P1133 00, P2270 00. P2A00 00
HO2S low signal | P2A00 00 | P0131 00, P0132 00, P0133 00, P0134 00, P0138 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P1133 00, P2A00 00 | P0134 00, P0138 00, P0140 00, P1133 00, P2A00 00 | P2271 00, P2A00 00

### Typical Scan Tool Data

#### HO2S Sensor 1 Voltage

Circuit | Normal Range | Short to Ground | Open | Short to Voltage
--- | --- | --- | --- | ---
HO2S High Signal | 200-800 mV | 0 mV | Approximately 470 mV | Approximately 1100 mV
HO2S Low Signal | 200-800 mV | 450 mV | Approximately 470 mV | Approximately 445 mV

### Circuit/System Description

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. The heated oxygen sensor (HO2S) 1 and heated oxygen sensor (HO2S) 2 compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The heated oxygen sensor (HO2S) must reach operating temperature to provide an accurate voltage signal. Heating elements inside the heated oxygen sensor (HO2S) minimize the time required for the sensors to reach operating temperature. The engine control module (ECM) supplies the heated oxygen sensor (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 heated oxygen sensor (HO2S) voltage signal. Once the heated oxygen sensor (HO2S) 1 and heated oxygen sensor (HO2S) 2 reaches operating temperature and closed loop is achieved, the heated oxygen sensor (HO2S) generates a voltage within a range of 0 to 1000 mV that fluctuates above and below bias voltage. High heated oxygen sensor (HO2S) voltage indicates a rich exhaust stream. Low heated oxygen sensor (HO2S) voltage indicates a lean exhaust stream.

### Conditions for Running the DTC

#### P0133 00

• | DTCs P0068 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0112 00, P0113 00, P0117 00, P0118 00, P0120 00, P0121 00, P0122 00, P0123 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0443 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00 are not set.

• | The engine coolant temperature (ECT) sensor parameter is more than 70°C (158°F).

• | The ignition signal parameter is between 10 to 18 V.

• | The fuel level sensor parameter is more than 10%.

• | The engine run time parameter is more than 200 s.

• | The engine speed parameter is between 1000 to 3500 RPM.

• | The manifold absolute pressure (MAP) sensor parameter is more than 30 kPa.

• | The mass airflow (MAF) sensor parameter is between 11 to 50 g/s.

• | The loop status parameter is closed.

• | The throttle position indicated angle parameter is more than 5%.

• | DTC P01313 00 runs once per drive cycle when the above conditions are met for 2 s.

#### P0134 00

• | DTCs P0068 00, P0101 00, P0102 00, P010 00, P0106 00, P0107 00, P0108 00, P0112 00, P0113 00, P0117 00, P0118 00, P0120 00, P0121 00, P0122 00, P0123 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0443 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00 are not set.

• | The engine coolant temperature (ECT) sensor parameter is more than 70°C (158°F).

• | The ignition signal parameter is between 10 to 18 V.

• | The engine run time is more than 200 s.

• | DTC P0134 00 runs continuously when the above conditions are met.

#### P013A 00

• | DTCs P0030 00, P0036 00, P0053 00, P0054 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0120 00, P0121 00, P0122 00, P0123 00, P0131 00, P0132 00, P0133 00, P0134 00, P0135 00, P0137 00, P0138 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P0141 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0300 00, P0443 00, P1133 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00, P2270 00, P2271 00, P2A00 00 are not set.

• | The system voltage is between 10 to 18 V.

• | The fuel level is more than 10%.

• | Engine run time is equal to or more than 40 s.

• | The engine coolant is hotter than 50.25°C (122.45°F).

| Then

• | DFCO is active

• | The accelerator pedal position (APP) is stable

• | The torque converter clutch (TCC) is locked

• | DTC P013E 00 and P2270 00 have run and passed.

• | DTC P013A 00 runs once per trip

#### P013B 00

• | DTCs P0030 00, P0036 00, P0053 00, P0054 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0120 00, P0121 00, P0122 00, P0123 00, P0131 00, P0132 00, P0133 00, P0134 00, P0135 00, P0137 00, P0138 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P0141 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0300 00, P0443 00, P1133 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00, P2270 00, P2271 00, P2A00 00 are not set..

• | The system voltage is between 10 to 18 V.

• | The fuel level is more than 10%.

• | Engine run time is equal to or more than 40 s.

• | The engine coolant is hotter than 50.25°C (122.45°F).

| Then

• | DTCs P013A 00, P013E 00, P013F 00, P2270 00, and P2271 00 have run and passed.

• | DTC P013B 00 runs once per trip

#### P013E 00

• | DTCs P0030 00, P0036 00, P0053 00, P0054 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0120 00, P0121 00, P0122 00, P0123 00, P0131 00, P0132 00, P0133 00, P0134 00, P0135 00, P0137 00, P0138 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P0141 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0300 00, P0443 00, P1133 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00, P2270 00, P2271 00, P2A00 00 are not set.

• | The system voltage is between 10 to 18 V.

• | The fuel level is more than 10%.

• | Engine run time is equal to or more than 40 s.

• | The engine coolant is hotter than 50.25°C (122.45°F).

| Then

• | DEFCO is active.

• | The accelerator pedal position (APP) is stable.

• | The torque converter clutch (TCC) is locked.

• | DTCs P2270 00 has run and passed.

• | DTC P013E 00 runs once per trip

#### P013F 00

• | DTCs P0030 00, P0036 00, P0053 00, P0054 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0120 00, P0121 00, P0122 00, P0123 00, P0131 00, P0132 00, P0133 00, P0134 00, P0135 00, P0137 00, P0138 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P0141 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0300 00, P0443 00, P1133 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00, P2270 00, P2271 00, P2A00 00 are not set.

• | The system voltage is between 10 to 18 V.

• | The fuel level is more than 10%.

• | Engine run time is equal to or more than 40 s.

| Then

• | DTCs P013A 00, P013E 00, P2270 00, and P2271 00 have run and passed.

• | DTC P013F 00 runs once per trip

#### P0140 00

• | DTCs P0068 00, P0101 00, P0102 00, P010 00, P0106 00, P0107 00, P0108 00, P0112 00, P0113 00, P0117 00, P0118 00, P0120 00, P0121 00, P0122 00, P0123 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0443 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00 are not set.

• | The ECT sensor parameter is more than 70°C (158°F).

• | The ignition signal parameter is between 10 to 18 V.

• | The engine run time parameter is more than 200 s.

• | The loop status parameter is closed.

• | DTC P0140 00 runs once per drive cycle when the above conditions are met.

#### P1133 00

• | DTCs P0068 00, P0101 00, P0102 00, P010 00, P0106 00, P0107 00, P0108 00, P0112 00, P0113 00, P0117 00, P0118 00, P0120 00, P0121 00, P0122 00, P0123 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0443 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00 are not set.

• | The ECT sensor parameter is more than 70°C (158°F).

• | The engine speed parameter is between 1500 to 3500 RPM.

• | The system voltage is between 10 to 18 V.

• | The engine run time parameter is more than 200 s.

• | The loop status parameter is closed.

• | The throttle position indicated angle parameter is more than 5.

• | The fuel level sensor parameter is more than 10%.

• | The MAP sensor parameter is more than 30 kPa.

• | The MAF sensor parameter is between 11 to 50 g/s.

• | The engine coolant is hotter than 50.25°C (122.45°F).

• | DTC P1133 00 runs once per drive cycle when the above conditions are met for 2 s.

#### P2270 00

• | DTCs P0030 00, P0036 00, P0053 00, P0054 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0120 00, P0121 00, P0122 00, P0123 00, P0131 00, P0132 00, P0133 00, P0134 00, P0135 00, P0137 00, P0138 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P0141 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0300 00, P0443 00, P1133 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00, P2270 00, P2271 00, P2A00 00 are not set.

• | The system voltage is between 10 to 18 V.

• | The fuel level is more than 10%.

• | Engine run time is equal to or more than 255 s.

| Then

• | The engine speed is between 1100 to 3200 RPM.

• | The airflow is equal to or more than 0 g/s and equal to or less than 25 g/s.

• | The vehicle speed is equal to or more than 45 km/h (28 mph) and equal to or less than 129 km/h (80 mph).

• | The short term fuel trim is equal to or more than 0.9, and equal to or less than 1.065.

• | The loop status parameter is closed.

• | The evaporative emission (EVAP) diagnostics are not in control of purge.

• | The heater warm-up delay is more than 120 s.

• | The catalytic converter temperature is equal to or more than 650°C (1202°F), and equal to less than 900°C (1652°F).

• | DTC P2270 00 runs once per trip when all of the above conditions have been met for 2 s.

#### P2271 00

• | DTCs P0030 00, P0036 00, P0053 00, P0054 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0120 00, P0121 00, P0122 00, P0123 00, P0131 00, P0132 00, P0133 00, P0134 00, P0135 00, P0137 00, P0138 00, P013A 00, P013B 00, P013E 00, P013F 00, P0140 00, P0141 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0300 00, P0443 00, P1133 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00, P2270 00, P2271 00, P2A00 00 are not set.

• | The system voltage is between 10 to 18 V.

• | The fuel level is more than 10%.

• | Engine run time is equal to or more than 255 s.

| Then

• | DEFCO is active.

• | The accelerator pedal position (APP) is stable.

• | The torque converter clutch (TCC) is locked.

• | DTCs P013A 00, P013E 00, and P2270 00 have run and passed

• | DTC P2271 00 runs once per trip

#### P2A00 00

• | DTCs P0068 00, P0101 00, P0102 00, P0103 00, P0106 00, P0107 00, P0108 00, P0112 00, P0113 00, P0117 00, P0118 00, P0120 00, P0121 00, P0122 00, P0123 00, P0201 00, P0202 00, P0203 00, P0204 00, P0220 00, P0222 00, P0223 00, P0443 00, P1516 00, P2101 00, P2119 00, P2135 00, P2176 00 are not set.

• | The engine run time parameter is more than 100 s.

• | The engine speed parameter is between 1000 to 3400 RPM.

• | The ignition signal parameter is between 10 to 18 s.

• | The mass airflow (MAF) sensor parameter is between 10 to 30 g/s.

• | The engine coolant is hotter than 70°C (158°F).

• | DTC P2A00 00 runs continuously when the above conditions are met for 5 s.

### Conditions for Setting the DTC

#### P0133 00

• | The ECM detects that the heated oxygen sensor (HO2S) 1 rich-to-lean or lean-to-rich average response time is more than 0.1 s.

• | DTC P0133 00 sets within 60 s when the above condition is met.

#### P0134 00

• | The ECM detects that the heated oxygen sensor (HO2S) 1 parameter is between 400-500 mV for 100 s.

• | The throttle position indicated angle parameter changes more than 1%, 3 times.

• | DTC P0134 00 sets within 100 s when the above condition is met.

#### P013A 00

The ECM detects that the accumulated mass air flow monitored during rich-to-lean transitions between 550 to 775 mV is more than 15 grams.

#### P013B 00

The ECM detects that the accumulated mass air flow monitored during rich-to-lean transitions between 550 to 775 mV is more than 15 grams.

#### P013E 00

The ECM detects that the heated oxygen sensor (HO2S) 2 cannot achieve voltage below 450 mV within 8 grams of accumulated air flow.

#### P013F 00

The ECM detects that the heated oxygen sensor (HO2S) 2 cannot achieve voltage above 550 mV within 28 grams of accumulated air flow.

#### P0140 00

• | The ECM detects that the heated oxygen sensor (HO2S) 2 parameter is between 425-475 mV.

• | The throttle position indicated angle parameter changes more than 1% 3 times.

• | DTC P0140 00 sets within 100 s when the above conditions are met.

#### P1133 00

• | The ECM detects that the heated oxygen sensor (HO2S) 1 rich-to-lean counts, or the lean-to-rich counts are less than a calibrated value.

• | DTC P1133 00 sets within 60 00 when the above condition is met.

#### P2270 00

• | The ECM detects that the heated oxygen sensor (HO2S) 2 sensor cannot achieve voltage equal to or more than 775 mV.

| and

• | The ECM detects that the accumulated mass air flow monitored during the Stuck Lean Voltage Test is more than 45 grams.

#### P2271 00

• | The ECM detects that the heated oxygen sensor (HO2S) 2 sensor cannot achieve voltage equal to or less than 100 mV.

| and

• | The ECM detects that the accumulated mass air flow monitored during the stuck rich voltage test is more than 20 grams.

#### P2A00 00

• | The ECM detects that the heated oxygen sensor (HO2S) 1 loop status parameter is open.

• | DTC P2A00 00 sets within 50 s when the above condition is met

### Action Taken When the DTC Sets

• | DTCs P0133 00, P0134 00, P013E 00, P013F 00, P0140 00, P1133 00, P2270 00, P2271 00, P2A00 00 are Type B DTCs.

• | DTCs P013A 00 and P013B 00 are Type A DTCs.

### Conditions for Clearing the DTC

• | DTCs P0133 00, P0134 00, P013E 00, P013F 00, P0140 00, P1133 00, P2270 00, P2271 00, P2A00 00 are Type B DTCs.

• | DTCs P013A 00 and P013B 00 are Type A DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

• | Heated Oxygen Sensor Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References

### Circuit/System Verification

1. If any heated oxygen sensor (HO2S) heater DTCs are set, perform those diagnostics first.
2. Allow the engine to reach operating temperature.
3. Engine running, observe the affected heated oxygen sensor (HO2S) parameter with a scan tool.

• | The heated oxygen sensor (HO2S) 1 value should vary from below 200 mV to above 800 mV and respond to fueling changes.

• | The heated oxygen sensor (HO2S) 2 value should change more than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1500 RPM for 30 s.

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

4. The affected heated oxygen sensor (HO2S) may be damaged due to contamination. Prior to replacing the affected heated oxygen sensor (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

• | Engine coolant consumption, refer to Loss of Coolant

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.

### Circuit/System Testing

Note: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the scan tool and wait 60 s to ensure all modules are powered down.
2. Ignition OFF, disconnect the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) harness connector.
3. Ignition OFF, measure for less than 5 Ω between B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) low signal circuit terminal 3 and ground.

⇒ | If more than the specified range, test the appropriate B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) low signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM)

4. Ignition ON, verify the appropriate scan tool HO2S Sensor 1or HO2S Sensor 2 parameter is approximately 450 mV.

⇒ | If more than the specified value, test the appropriate B52A Heated Oxygen Sensor (HO2S) high signal circuit terminal 4 or a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

⇒ | If less than the specified value, test the appropriate B52A Heated Oxygen Sensor (HO2S) high signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

5. Ignition ON, install a 3A fused jumper wire at the appropriate B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) high signal circuit terminal 4. Toggle the jumper wire between the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) low signal circuit terminal 3 and battery voltage. Verify the appropriate scan tool HO2S parameter toggles between 0 mV and approximately 1000 mV.

⇒ | If the appropriate scan tool HO2S parameter does not toggle correctly, test the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) High Signal Circuit for an open/high resistance. If the circuits test normal, replace the K20 Engine Control Module (ECM).

6. If all circuits test normal, replace the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S).

### Repair Instructions

Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution in the Preface section.

Perform the Diagnostic Repair Verification

• | Heated Oxygen Sensor Replacement - Sensor 1

• | Heated Oxygen Sensor Replacement - Sensor 2

• | Control Module References for ECM replacement, setup, and programming