• | 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. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
HO2S High Signal | P0131, P0171, P1133, P2A00 | P0131, P0133, P0134, P1133, P2A00 | P0131, P0133, P0134, P1133, P2A00 | P0132, P0134, P0172, P1133, P2A00 | P0133, P0134, P1133, P2A00 |
HO2S Low Signal | P2A00 | P0133, P0134, P1133, P2A00 | P0133, P0134, P1133, P2A00 | P0134, P1133, P2A00 | P2A00 |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
HO2S High Signal | P0137, P0140, P2270 | P0140, P2271 | P0140, P2271 | P0138, P0140, P2271 | P0140, P2271 |
HO2S Low Signal | -- | P0140, P2270, P2271 | P0140, P2A01, P2270, P2271 | P0138, P0140, P2270, P2271 | P2271 |
HO2S Sensor Voltage Circuits | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
HO2S High Signal | 0-1000 mV | 0-45 mV | Approximately 450 mV | Approximately 1106 mV |
HO2S Low Signal | 0-1000 mV | 0-1000 mV | 0-800 mV | 50-1106 mV |
HO2S Sensor Voltage Circuits | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
HO2S High Signal | 0-1000 mV | 0-45 mV | Approximately 450 mV | Approximately 1106 mV |
HO2S Low Signal | 0-1000 mV | 0-1000 mV | 400-600 mV | 50-1106 mV |
Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the PCM operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.
• | DTCs P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P1516, P2101, P2119, P2135 are not set. |
• | DTCs P0411, P0412, P0418, P2400, P2430-P2433, P2444, where applicable, are not set. |
• | The system voltage is between 10-18 volts. |
• | The scan tool special functions are not active. |
• | The Air Fuel Ratio parameter is between 0.9-1.1. |
• | The TP Indicated Angle parameter is between 3-40 percent. |
• | The Loop Status parameter is closed. |
• | The ECT parameter is less than 131°C (267°F). |
• | The traction control is not active. |
• | The above conditions have been met for at least 3 seconds. |
• | DTCs P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P1516, P2101, P2119, P2135 are not set. |
• | DTCs P0411, P0412, P0418, P2400, P2430-P2433, P2444, where applicable, are not set. |
• | The system voltage is between 10-18 volts. |
• | The scan tool special functions are not active. |
• | The TP Indicated Angle parameter is less than 46 percent. |
• | The Air Fuel Ratio parameter is between 0.9-1.1. |
• | The above conditions must be met for at least 3 seconds. |
• | The PCM detects that the HO2S 1 signal voltage is less than 52 mV for more than 26 seconds. |
• | This diagnostic runs continuously. |
• | The PCM detects that the HO2S 1 signal voltage is more than 1,050 mV for more than 9 seconds. |
• | This diagnostic runs continuously. |
• | The PCM detects that the HO2S 2 signal voltage remains below 52 mV for more than 60 seconds. |
• | This diagnostic runs continuously. |
• | The HO2S 2 voltage is more than 1,050 mV for longer than 60 seconds. |
• | This diagnostic runs continuously. |
DTCs P0131, P0132, P0137, and P0138 are Type B DTCs.
DTCs P0131, P0132, P0137, and P0138 are Type B DTCs.
• | Circuit Testing |
• | Wiring Repairs |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | The pre-catalyst oxygen sensors value should vary from below 200 mV to above 800 mV and respond to fueling changes. |
⇒ | The post-catalyst oxygen sensors 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 1,500 RPM for 30 seconds. |
Caution: Refer to Silicon Contamination of Heated Oxygen Sensors Caution in the Preface section.
• | 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. |
Note: All modules must be powered down or misdiagnosis may result.
⇒ | If more than the specified range, test the appropriate HO2S low signal circuit for an open/high resistance. If the circuit tests normal, replace the PCM. |
⇒ | If more than the specified value, test the appropriate HO2S high signal circuit for a short to voltage. If the circuit tests normal, replace the PCM. |
⇒ | If less than the specified value, test the appropriate HO2S high signal circuit for a short to ground. If the circuit tests normal, replace the PCM. |
⇒ | If the appropriate scan tool HO2S parameter does not toggle correctly, test the HO2S high signal circuit for an open/high resistance. If the circuits test normal, replace the PCM. |
Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution in the Preface section.
Note: For DTCs P0131 and P0132, in order to ensure that the performance of the catalyst has not been affected by the fault that set this DTC, operate the vehicle within the Conditions for Running and setting DTC P0420, and verify that DTC P0420 runs and passes. Refer to DTC P0420.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for PCM replacement, setup, and programming |