P0134

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The Heated Oxygen Sensor (HO2S) is a sensor used to detect oxygen-content in the exhaust. The Powertrain Control Module (PCM) supplies the sensor with a signal circuit and a ground circuit. The PCM supplies a bias voltage between the circuits. The sensor varies the voltage based on the oxygen content in the exhaust. When the exhaust stream is lean (more oxygen), the sensor produces a low voltage signal. When the exhaust stream is rich (less oxygen), the sensor produces a high voltage signal.

The PCM monitors the HO2S signal during closed loop. To correct for rich or lean conditions, the PCM adjusts the injector pulse width. If HO2S bank 1 sensor 1 remains at or near the bias voltage for a calibrated period of time, DTC P0134 will set.

CONDITIONS FOR RUNNING THE DTC
^ No MAF, TP, EVAP, IAT, MAP, AIR (if equipped), ECT, or Injector DTCs set
^ EGR flow diagnostic inactive
^ AIR diagnostic test (if equipped) inactive.
^ Catalyst diagnostic test inactive
^ System voltage between 9-18 volts.
^ Engine running for more than 200 seconds.
^ Change in TP angle more than 5 percent occurs at least 4 times.

CONDITIONS FOR SETTING THE DTC
HO2S bank 1 sensor 1 signal voltage remain within 400 and 500 mV for approximately 57 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
^ The PCM stores the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions in Symptoms. Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
5. Check the HO2S bank 1 sensor 1 wiring, the PCMs response. With the harness connector terminals jumpered together, the scan tool should display an HO2S bank 1 sensor 1 voltage below 75 mV.
9. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.