Circuit Description
The powertrain control module (PCM) continuously monitors the heated oxygen sensor (HO2S) activity for 60 seconds. During the monitor period the PCM counts the number of times that the HO2S responds from rich to lean and from lean to rich, and adds the amount of time that was needed to complete all transitions. With this information, the PCM can determine the average time for all transitions. If the average response time is too slow, a DTC will set.
The PCM determines the lean to rich transition when the HO2S voltage changes from less than 300 mV to more than 600 mV. The PCM determines the rich to lean transition when the HO2S voltage changes from more than 600 mV to less than 300 mV. An HO2S that responds too slowly will set this DTC.
Conditions for Running the DTC
| • | DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0300, P0410, P0440, P0442, P0446, P0452, P0453, P1258, P1415, P1416, or P1441 are not set. |
| • | The engine coolant temperature (ECT) is more than 50°C (122°F). |
| • | The ignition 1 signal is between 9-18 volts. |
| • | The loop status is closed. |
| • | The engine speed between 1,000-2,300 RPM. |
| • | The engine air flow is between 20-50 grams per second. |
| • | The evaporative emission (EVAP) purge solenoid is more than 0 percent. |
| • | The engine run time is more than 160 seconds. |
| • | The throttle position (TP) is more than 5 percent. |
| • | The fuel tank level remaining is more than 10 percent. |
| • | The above conditions exist for 60 seconds. |
Conditions for Setting the DTC
| • | The lean to rich response, defined as less than 300 mV to more than 600 mV, average time is more than a calibrated amount. |
| • | The rich to lean response, defined as more than 600 mV to less than 300 mV, average time is more than a calibrated amount. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step determines if the fault is present. This test may take 5 minutes for the diagnostic to run.
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When DTCs P0133 and P0153 are set at the same time, a fuel contamination condition is probably present.
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An exhaust leak 15.2-30.1 cm (6-12 inches) away from the HO2S can cause a DTC to set.
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This step verifies whether a good ground circuit is available.
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This step verifies the integrity of the HO2S low signal circuit to the PCM.
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This step verifies the integrity of the HO2S high signal circuit to the PCM.
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Certain RTV silicone gasket materials release vapors that can contaminate the HO2S. Silicone in the fuel can also cause silicone contamination. If the sensors appear silicone-contaminated, and if and all the silicone sealant is a non-silicone base, advise the customer to try a different fuel company. A missing fuel filler restrictor indicates the customer may have used leaded fuel.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||
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Important: If any DTCs except DTC P0133 or DTC P0153 are set, refer to those DTCs before proceeding with this diagnostic table.
Did DTC P0133 or P0153 fail this ignition? | -- | Go to Step 3 | Go to Intermittent Conditions | |||||||||
Did both DTC P0133 and P0153 fail this ignition? | -- | Go to Step 8 | Go to Step 4 | |||||||||
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 5 | |||||||||
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 6 | |||||||||
Does the scan tool indicate a voltage that is within the specified range? | 350-550 mV | Go to Step 7 | Go to Step 10 | |||||||||
Does the scan tool indicate a voltage that is below the specified value? | 200 mV | Go to Step 13 | Go to Step 9 | |||||||||
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Important: Before you replace a sensor, determine and correct the cause of the
contamination. Inspect for the following conditions:
Replace the affected heated oxygen sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 and Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Did you complete the replacement? | -- | Go to Step 14 | -- | |||||||||
9 |
Does the DMM indicate a voltage that is near the specified value? | 5 V | Go to Step 12 | Go to Step 11 | ||||||||
10 |
Notice: A short to voltage on the heated oxygen sensor (HO2S) high signal circuit may damage the HO2S. Repair the HO2S high signal circuit for a short to ground, or for a short to voltage. Refer to Wiring Repairs in Wiring Systems . Did you complete the repair? | -- | Go to Step 14 | -- | ||||||||
11 | Repair the open HO2S low signal circuit, or repair the poor PCM connections. Refer to Wiring Repairs in Wiring Systems . Did you complete the repair? | -- | Go to Step 14 | -- | ||||||||
12 | Repair the HO2S high signal circuit for an open, or repair the poor PCM connections. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||||
13 | Replace the affected HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 and Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||||
14 |
Does the DTC run and pass? | -- | Go to Step 15 | Go to Step 2 | ||||||||
15 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |||||||||
