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 P0133: HO2S/O2S Slow Response Bank 1 Sensor 1DTC P0153: HO2S/O2S Slow Response Bank 2 Sensor 1
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
HO2S Bank 1 Sensor 1 Signal | P0131 | -- | P0132 | P0133, P0134 |
HO2S Bank 1 Sensor 2 Signal | P0137 | -- | P0138 | P0139, P0140 |
HO2S Bank 2 Sensor 1 Signal | P0151 | -- | P0152 | P0153, P0154 |
HO2S Bank 2 Sensor 2 Signal | P0157 | -- | P0158 | P0159, P0160 |
Low Reference | -- | -- | P0132, P0138, P0152, P0158 | -- |
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 DTCs
| • | DTCs P0016, P0102, P0103, P0107, P0108, P0117, P0118, P0121, P0122, P0123, P0131, P0132, P0134, P0151, P0152, P0154, P0171, P0172, P0174, P0175, P0221, P0222, P0223, P0230, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0335, P0336, P0337, P0340, P0443, P0458, and P0459 are not set. |
| • | The mass air flow (MAF) is between 15-250 kg/h. |
| • | The engine speed is between 608-3,208 RPM. |
| • | The engine coolant temperature (ECT) is greater than 50°C (122°F). |
| • | The exhaust gas temperature at the HO2S is greater than 400°C (752°F). |
| • | The fuel system is in Closed Loop. |
| • | The DTCs run continuously when the above conditions are met for 2 seconds. |
Conditions for Setting the DTCs
The engine control module (ECM) detects that the HO2S 1 rich-to-lean average response time or the lean-to-rich average response time is greater than calibrated.
Action Taken when the DTCs Set
DTCs P0133 and P0153 are Type B DTCs.
Conditions for Clearing the MIL/DTCs
DTCs P0133 and P0153 are Type B DTCs.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, observe the DTC Information with a scan tool. DTCs P0133 and P0153 should not set.
- Engine running, observe the scan tool HO2S voltage parameter. The reading should fluctuate above and below the range of 350-550 mV.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Verify none of the following conditions exist:
- If all conditions test normal, test or replace the appropriate HO2S.
| • | Lean or rich fuel injectors--Refer to 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 that is contaminated--Refer to Alcohol/Contaminants-in-Fuel Diagnosis. |
| • | Fuel saturation of the evaporative emission (EVAP) canister |
| • | Exhaust leaks near the HO2S |
| • | Engine vacuum leaks |
| • | Engine oil consumption |
| • | Engine coolant consumption--Refer to Loss of Coolant. |
| ⇒ | If you find any of the above conditions, repair as necessary. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for engine control module replacement, setup, and programming
