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.
This diagnostic will only run once per ignition cycle. The PCM monitors the rich-to-lean and lean-to-rich transition time. A transition is defined as, the HO2S voltage changes from above 600 mV to below 300 mV or from below 300 mV to above 600 mV. If the PCM detects that the transition time is too long, DTC P0133 or P0153 sets.
• | 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 ECT sensor parameter is more than 50°C (122°F). |
• | The Ignition 1 Signal parameter is between 9-18 volts. |
• | The Loop Status Parameter is Closed. |
• | The Engine Speed Parameter is between 1,000-2,300 RPM. |
• | The MAF sensor parameter is between 18-50 g/s. |
• | The EVAP purge solenoid command parameter is more than 0 percent. |
• | The Engine Run Time Parameter is more than 160 seconds. |
• | The TP indicated angle parameter is 5 percent more than the value observed at idle. |
• | The fuel level parameter is more than 10 percent. |
• | The above conditions are met for 60 seconds. |
• | 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. |
• | 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. |
• | 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. |
The numbers below refer to the step numbers on the diagnostic table.
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 tests the integrity of the signal circuit to the PCM.
This step tests the integrity of the signal circuit to the PCM.
Step | Action | Values | Yes | No | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||
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 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 | |||||||||
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 | |||||||||
8 |
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 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? | -- | 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 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 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 15 | ||||||||
15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |