Circuit Description
The powertrain control module (PCM) continuously monitors the heated oxygen sensor (HO2S) activity for 60 seconds. During the monitoring period, the PCM counts the times that the HO2S responds from rich to lean and from lean to rich, and adds the time it took 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 sets.
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. If the HO2S responds too slowly a DTC will set.
Conditions for Running the DTC
| • | DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0300, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1415, P1416, P1441, P1514, P1515, P1516, P1517, or P1518 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 18-50 g/s. |
| • | The evaporative emission (EVAP) purge solenoid is more than 0 percent. |
| • | The engine run time is more than 160 seconds. |
| • | The throttle position (TP) indicated angle is 5 percent more than the value observed at idle. |
| • | The fuel tank level remaining is more than 10 percent. |
| • | The above conditions are met 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. |
Diagnostic Aids
Important:
• Before you service the PCM and throttle actuator control (TAC)
module, remove any debris from the module connector surfaces. Inspect the
module connector gaskets when you diagnose or replace the modules.
Ensure that the gaskets are correctly installed. The gaskets prevent
contaminate intrusion into the modules. • Use the J 35616
Connector Test Adapter Kit for any test that requires probing
the PCM or probing a component harness connector. Using this kit prevents
damage to the harness and component terminals. Refer to
Using Connector Test Adapters
in
Wiring Systems.
| • | This diagnostic only runs once per ignition cycle. |
| • | A malfunction in the HO2S heater circuits causes a DTC to set. Inspect the HO2S heater circuits for intermittent opens and connections. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provides the supply of oxygen. Inspect the HO2S wires and connections for breaks or for contamination. Refer to Wiring Repairs in Wiring Systems. |
| • | For an intermittent condition, refer to Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the fault is present. This test may take 5 minutes for the diagnostic to run.
-
When DTCs P0133 and P0153 are set at the same time a fuel contamination concern is present.
-
An exhaust leak 6-12 inches away from the HO2S can cause a DTC to set.
-
This step verifies whether a good ground circuit is available.
-
This step tests the integrity of the signal circuit to the PCM.
-
This step tests the integrity of the signal circuit to the PCM.
-
Certain room-temperature vulcanizing (RTV) silicone gasket materials release vapors that can contaminate the HO2S. Silicone in the fuel can also cause silicone contamination. If the sensors appear to be silicone-contaminated and if all the silicone sealant is a non-silicone base, advise the customer to try a different fuel company.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||
|
Important: If any DTCs are set except DTC P0133 or P0153, refer to those DTCs before proceeding with this diagnostic table.
Did DTC P0133 or P0153 fail this ignition? | -- | Go to Step 3 | Go to Diagnostic Aids | |||||||||
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 | |||||||||
Inspect for the following conditions:
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 6 | |||||||||
Does the scan tool indicate a voltage within the specified range? | 350-550 mV | Go to Step 7 | Go to Step 10 | |||||||||
Is the voltage less than the specified value? | 200 mV | Go to Step 13 | Go to Step 9 | |||||||||
|
Important: Determine and correct the cause of the contamination before replacing
a sensor. Inspect for the following conditions:
Replace the affected Heated Oxygen sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Did you complete the replacement? | -- | Go to Step 14 | -- | |||||||||
9 |
Is the voltage near the specified value? | 5 V | Go to Step 12 | Go to Step 11 | ||||||||
10 | Repair the 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? | -- | -- | |||||||||
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 HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or 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 | |||||||||
