P1134

DTC P1134 O2 BANK 1 SENSOR 1 TRANSITION RATIO




Circuit Description
The powertrain control module (PCM)/engine control module (ECM) monitors the oxygen sensor (O2S 1) 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 1 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 1 transition time ratio is not within this range, DTC P1134 will be set, indicating that the O2S 1 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, P0443, P0506, P0507, P1130, P1404 and P1627 not set.
- Engine is operating in closed loop.
- Purge D.C. is greater than 0%
- Engine coolant temperature (ECT) is above 72 °C (162 °F).
- The engine has been operating for at least 120 seconds.
- Calculated airflow is between 9 and 42 grams/sec.
- Canister purge duty cycle is greater than 2%.
- Engine speed is between 1600 rpm and 4000 rpm.
- 0 second delay after conditions are met.
- Airflow is between 7 and 40 g/sec.

Action Taken When the DTC Sets
- The PCM/ECM will illuminate the malfunction indicator lamp (MIL) after the second consecutive trip in which the fault is detected.
- Open loop fuel control will be in effect.
- The PCM/ECM will store conditions which were present when the DTC was set as Freeze Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC
- The PCM/ECM will turn the MIL OFF on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present.
- A history DTC P1134 will clear after 80 consecutive warm-up cycles have occurred without a fault.
- DTC P1134 can be cleared by using the scan tool CLEAR INFO function or by disconnecting the PCM/ECM battery feed.

Diagnostic Aids
A malfunction in the O2S 1 ignition feed or ground circuit may cause a DTC P1134 to set. Check O2S 1 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 1).
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.

Steps 1 To 5:

Steps 6 To 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.