P1154

DTC P1134 or P1154

Circuit Description

The powertrain control module (PCM) monitors the heated oxygen sensor (HO2S) activity. During the monitoring 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 needed to complete all transitions. With this information, an average time for all transitions can be determined. The PCM then divides the rich-to-lean average by the lean-to-rich average in order to obtain a ratio. A DTC P1134 or a P1154 sets if the HO2S ratio is not within range.


DTC Descriptors

This diagnostic procedure supports the following DTCs.

- DTC P1134 HO2S Transition Time Ratio Bank 1 Sensor 1

- DTC P1154 HO2S Transition Time Ratio Bank 2 Sensor 1


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, P0443, P0496, P1111, P1112, P1114, P1115, P1121, or P1122 are not set.

- The engine coolant temperature (ECT) is more than 60°C (140°F).

- The ignition 1 signal is between 10-18 volts.

- The loop status is CLOSED.

- The engine speed between 1,200-3,000 RPM.

- The engine air flow is between 20-55 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.

- DTC P1134 and P1154 run once per ignition cycle when the above conditions are met.


Conditions for Setting the DTC

The PCM determines that the HO2S transition time ratio is more than or less than the calibrated range.

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 tails, 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 L) 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

DTC P1134 Or P1154 Steps 1-8:

DTC P1134 Or P1154 Steps 9-15:

The numbers below refer to the step numbers on the diagnostic table.

2. This step determines it the condition is present. This test may take 5 minutes for the diagnostic to run.

3. When DTCs P1134 and P1154 are set at the same time, a fuel contamination condition is likely.

4. An exhaust leak 6-12 inches away from the H02S can cause a DTC to set.

5. This step tests whether a good ground circuit is available.

6. This step tests the integrity of the HO2S high signal circuit to the PCM.

7. This step tests the integrity of the HO2S high signal circuit to the PCM.

8. 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 silicon-contaminated, and if 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.