P1134

P1134 O2 Bank 1 Sensor 1 Transition Ratio




Circuit Description
The powertrain control module (PCM)/engine control module (ECM) monitors the Oxygen Sensor (O2S) activity for 60 seconds after closed loop and stoichiometric operation have been established. During the monitoring period the PCM/ECM counts the number of times that the O2S responds from rich-to-lean and adds the amount of time it took to complete all transitions. With this information, an average time for all transitions can be determined. The PCM/ECM then divides the rich-to-lean average by the lean-to-rich average to obtain a ratio. If the O2S transition time ratio is not within this range, DTC P1134 will be set, indicating that the O2S is not responding as expected to changes in exhaust oxygen content.

Conditions for Setting the DTC
- DTCs P0106, P0107, P0108, P0117, P0118, P0121, P0122, P0123, P0131, P0132, P0134, P0171, P0172, P0201, P0202, P0203, P0204, P0300, P0336, P0337, P0351, P0352, P0402, P0404, P0405, P0406, P0506, P0507, P1404 , P1441 and P1627 not set.

- Engine is operating in closed loop.
- Purge D.C. is greater than 0%
- Engine coolant temperature (ECT) is above 162 °F (72 °C).
- The engine has been operating for at least 120 seconds.
- Engine speed is between 1600 rpm and 4000 rpm.
- Airflow is between 9 and 40 g/sec.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate on the second consecutive drive trip that the diagnostic runs and fails.
- The PCM/ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history Diagnostic Trouble Code (DTC) is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn off after three consecutive ignition cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm-up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.

Diagnostic Aids
A malfunction in the O2S ignition feed or ground circuit may cause a DTC P1134 to set. Check O2S circuitry for intermittent faults or poor connections. If connections and wiring are OK and DTC P1134 continues to set replace the Bank 1 Sensor 1(O2S).
Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Step 1 - 6:

Step 7 - 15:

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Chart.
3. A condition that affects pre-converter and post-converter oxygen sensors indicates probable contamination. To avoid damaging replacement sensors, correct the condition which caused the contamination before replacing the affected sensors.
5. This step checks for conditions which may cause the oxygen sensor to appear faulty. Correct any of the described conditions if present.
8. To avoid damaging replacement sensors, correct the condition which caused the contamination before replacing the affected sensors