• | 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. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
HO2S High Signal | P0131, P0132, P0134, P0137, P0140, P0151, P0154, P1133, P1153, P2A00, P2A01, P2A03 | P0131, P0133, P0134, P0137, P0140, P0151, P0153, P0154, P1133, P1153, P2A00, P2A01, P2A03 | P0131, P0133, P0134, P0137, P0140, P0153, P0154, P1133, P1153, P2A00, P2A01, P2A03 | P0132, P0134, P0138, P0140, P0152, P0154, P1133, P1153, P2A00, P2A01, P2A03 | P0133, P0134, P0140, P0153, P1133, P1153, P2A00, P2A01, P2A03 |
HO2S Low Signal | P2A00, P2A01, P2A03 | P0131, P0133, P0134, P0138, P0140, P0151, P0153, P0154, P1133, P1153, P2A00, P2A01 | P0131, P0133, P0134, P0138, P0140, P0153, P0154, P1133, P1153, P2A00, P2A01, P2A03 | P0134, P0138, P0140, P0152, P0153, P0160, P1133, P1153, P2A00, P2A01, P2A03 | P2A00, P2A01, P2A03 |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Normal Range: 200-800 mV | |||
HO2S High Signal | 0 mV | Approximately 470 mV | Approximately 1,100 mV |
HO2S Low Signal | 455 mV | Approximately 450 mV | Approximately 445 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 control module supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the control module 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, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Loop Status parameter is Closed. |
• | The Ignition 1 Signal parameter is between 10-18 volts. |
• | The Fuel Tank Level Remaining parameter is more than 10 percent. |
• | The Throttle Position (TP) Sensor parameter is between 0-50 percent. |
• | The equivalence ratio is between 0.99-1.01. |
• | DTC P0151 runs the test continuously when the above conditions are met for 3 seconds. |
• | DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Loop Status parameter is Closed. |
• | The Ignition 1 Signal parameter is between 10-18 volts. |
• | The Fuel Tank Level Remaining parameter is more than 10 percent. |
• | The Throttle Position (TP) Sensor parameter is between 0-60 percent. |
• | The equivalence ratio is between 0.99-1.01. |
• | DTC P0152 runs the test continuously when the above conditions are met for 3 seconds. |
• | The control module detects that the HO2S Bank 2 Sensor 1 Voltage parameter is less than 100 mV. |
• | DTC P0151 sets within 3 seconds when the above condition is met. |
• | The control module detects that the HO2S Bank 2 Sensor 1 Voltage parameter is more than 950 mV. |
• | DTC P0151 sets within 3 seconds when the above condition is met. |
DTCs P0151 and P0152 are Type B DTCs.
DTCs P0151 and P0152 are Type B DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
• | 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. |
Notice: Refer to Silicon Contamination of Heated Oxygen Sensors Notice 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 . |
Important: 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 ECM. |
⇒ | 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 ECM. |
⇒ | 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 ECM. |
⇒ | 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 ECM. |
Notice: Refer to Heated Oxygen Sensor Resistance Learn Reset Notice in the Preface section.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |