Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
HO2S High Signal | P0131, P0132, P0134, P0137, P0140, P0151, P0154, P0157, P0160, P1133, P1153, P2A00, P2A01, P2A03, P2A04 | P0131, P0133, P0134, P0137, P0140, P0151, P0153, P0154, P0157, P0160, P1133, P1153, P2A00, P2A01, P2A03, P2A04 | P0131, P0133, P0134, P0137, P0140, P0153, P0154, P1133, P1153, P2A00, P2A01, P2A03, P2A04 | P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160, P1133, P1153, P2A00, P2A01, P2A03, P2A04 | P0133, P0134, P0140, P0153, P0160, P1133, P1153, P2A00, P2A01, P2A03, P2A04 |
HO2S Low Signal | P2A00, P2A01, P2A03, P2A04 | P0131, P0133, P0134, P0138, P0140, P0151, P0153, P0154, P0157, P0160, P1133, P1153, P2A00, P2A01 | P0131, P0133, P0134, P0138, P0140, P0153, P0154, P1133, P1153, P2A00, P2A01, P2A03, P2A04 | P0134, P0138, P0140, P0152, P0153, P0158, P0160, P1133, P1153, P2A00, P2A01, P2A03, P2A04 | P2A00, P2A01, P2A03, P2A04 |
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
---|---|---|---|---|
HO2S High Signal | 200-800 mV | 0 mV | Approximately 470 mV | Approximately 1,100 mV |
HO2S Low Signal | 200-800 mV | 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, P0128, P0201, P0202, P0203, P0204, 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) Indicated Angle parameter is between 0-50 percent. |
• | The equivalence ratio is between 0.99-1.01. |
• | DTC P0131 runs the lean 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, 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 P0132 runs the rich 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, 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 Power Enrichment parameter is active for more than 3 seconds. |
• | The equivalence ratio is between 0.99-1.01. |
• | DTC P0137 runs the power enrichment test during each occurrence of power enrichment, 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, 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 TP Sensor parameter is between 0-50 percent. |
• | The equivalence ratio is between 0.99-1.01. |
• | DTC P0138 runs the rich 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, 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, 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. |
• | 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 Engine Run Time parameter is more than 100 seconds. |
• | The Engine speed parameter is between 500-5,000 RPM. |
• | The Ignition 1 Signal parameter is between 10-18 volts. |
• | The Mass Airflow (MAF) Sensor parameter is between 3-30 g/s. |
• | The ECT Sensor parameter is more than 70°C (158°F). |
• | DTC P2A00 runs continuously when the above conditions are met for 5 seconds. |
• | DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set. |
• | The engine is running. |
• | The Engine Run Time parameter is less than 260 seconds. |
• | DTC P2A01 runs the passive test once per drive cycle when the above conditions are met for 2 seconds. |
• | DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set. |
• | The Engine Run Time parameter is more than 260 seconds. |
• | The ignition 1 Signal parameter is between 10-18 volts. |
• | The MAF sensor parameter is between 0.5-50 g/s. |
• | The Engine Speed parameter is between 500-5,000 RPM. |
• | The Vehicle Speed parameter is between 24-145 km/h (20-80 mph). |
• | The Short Term FT parameter is between 5 and -5 percent. |
• | DTC P2A01 runs the intrusive test once per drive cycle when the above conditions are met for 1 second. |
• | DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set. |
• | The Engine Run Time parameter is more than 100 seconds. |
• | The ignition 1 Signal parameter is between 10-18 volts. |
• | The MAF sensor parameter is between 3-30 g/s. |
• | The Engine Speed parameter is between 500-5,000 RPM. |
• | DTC P2A01 runs continuously when the above conditions are met for 5 seconds. |
• | The control module detects that the HO2S 1 Voltage parameter is less than 25 mV. |
• | DTC P0131 sets within 100 seconds during the lean test when the above condition is met. |
• | The control module detects that the HO2S 1 parameter is more than 950 mV. |
• | DTC P0132 sets within 15 seconds during the rich test when the above condition is met. |
• | The control module detects that the HO2S 2 voltage parameter is less than 75 mV. |
• | DTC P0137 sets within 100 seconds during the lean test when the above condition is met. |
• | The control module detects that the HO2S 2 voltage parameter is more than 950 mV. |
• | DTC P0138 sets within 100 seconds during the rich test when the above condition is met. |
• | 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. |
• | The control module detects that the Loop Status parameter is open. |
• | DTC P2A00 sets within 5 seconds when the above condition is met. |
• | The control module detects that the HO2S 2 did not transition below 299 mV and above 751 mV during the passive test. |
• | One of the following tests fail once per trip/runs until pass or fail reporting: |
- | Lean Intrusive Test--The control module detects that the HO2S 2 is more than 751 mV for 8 seconds. |
- | Rich Intrusive Test--The control module detects that the HO2S 2 is less than 299 mV for 8 seconds. |
• | DTC P2A01 sets within 2 minutes when the above conditions are met. |
• | The control module detects that the Loop Status parameter is open by not meeting the voltage criteria to enable close loop fueling. |
Voltage cannot be between 250-600 mV for 10 seconds after the O2 has seen a ready to go closed loop command. |
• | DTC P2A00 sets within 5 seconds when the above condition is met. |
DTC P0131, P0132, P0137, P0138, P0151, P0152, P2A00, P2A01, P2A03 are Type B DTCs.
DTC P0131, P0132, P0137, P0138, P0151, P0152, P2A00, P2A01, P2A03 are Type B DTCs.
• | If any HO2S heater DTCs are set, perform those diagnostics first. |
• | Allow the engine to reach operating temperature. |
• | Engine running, observe the affected HO2S parameter with a scan tool. |
- | 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. |
• | The affected HO2S may be damaged due to contamination. Prior to replacing the affected HO2S, inspect for the following sources of contamination: |
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.
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for replacement, setup, and programming |