P0134

CIRCUIT DESCRIPTION
The powertrain control module (PCM) supplies a voltage of about 447 mV between the heated oxygen sensor (HO2S 1) high signal and the low signal circuit. The HO2S 1 varies the voltage within a range of about 1000 mV if the exhaust is rich, down through about 100 mV if the exhaust is lean.

The sensor is like an open circuit and produces no voltage when below 315°C (600°F).

Do not attempt to repair the HO2S. Replace the entire HO2S 1 assembly if the following conditions exist:
^ Damaged wiring
^ Damaged electrical connector
^ Damaged terminals

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0105, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0336, P0440, P0446, P0452, P0453, P0507, P0601, P0602, P0604, P0606, P1120, P1220, P1221, P1271, P1275, P1280, P1484, P1512, P1514, P1515, P1516, P1621, P1635, P1639, P1680, or P1681 are not set.
^ The fuel level sensor is more than 10 percent.
^ The ignition 1 signal is more than 10 volts.
^ The engine coolant temperature (ECT) is more than 80°C (176°F).
^ The throttle position (TP) indicated angle is between 15-50 percent for 20 seconds.
^ The accelerator pedal position (APP) indicated angle is more than 1.2 percent.
^ The manifold absolute pressure (MAP) sensor is more than 25 kPa.
^ The engine run time is more than 30 seconds.
^ The mass air flow (MAF) is more than 7 g/s.

CONDITIONS FOR SETTING THE DTC
The HO2S 1 voltage is between 399-499 mV for 125 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The malfunction indicator lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the fault active.
^ The PCM will record the operating conditions at the time that the diagnostic fails. This information will store in the Freeze Frame and Failure Records buffers.
^ A history DTC stores.
^ The vehicle will operate in Open Loop operation.

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.
^ Use a scan tool to clear the DTCs.

TEST DESCRIPTION

DTC P0134 - Steps 1-8:

DTC P0134 - Steps 9-14:

The numbers below refer to the step numbers on the diagnostic table.
2. When the system is operating correctly, the HO2S voltage should toggle above and below the specified values.
5. The specified value is what is measured on a correctly operating system.
6. The specified value is what is measured on a correctly operating system.