P0134

DTC P0134 02 BANK 1 SENSOR 1 NO ACTIVITY




Circuit Description
The powertrain control module (PCM)/engine control module (ECM) supplies a voltage of about 0.45 volts between terminals C14 and C15 (if measured with a 10 megaohm digital voltmeter, this may read as low as 0.32 volt) The Oxygen Sensor (O2S 1) varies the voltage within a range of about 1 volt if the exhaust is rich, down through about 0.10 volts if the exhaust is lean.
The sensor is like and open circuit and produces no voltage when it is below 315 °C (600 °F). An open sensor circuit or cold sensor causes Open Loop operation.
If the O2S 1 pigtail wiring, connector or terminal are damaged, the entire O2S 1 assembly must be replaced. Do not attempt to repair the wiring, connector or terminals. In order for the sensor to function properly, it must have a clean air reference provided to it. This clean air reference is obtained by way of the O2S 1 wire(s). Any attempt to repair the wires, connector or terminals could result in the obstruction of the air reference and degrade the O2S 1 performance. Refer to "Heated Oxygen Sensor".

Conditions for Setting the DTC
- Ignition is at 10 volts.
- O2S 1 voltage is between 400 mv and 500 mv for 125 seconds.
- Engine run time is greater than 60 seconds.
- No related malfunctions.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- 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.
- Coolant fan turns on.
- Vehicle will operate in Open Loop.

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
Normal scan tool voltage varies between 150 mv to 850 mv (0.15 volts to 0.85 volts) while in Closed Loop. If DTC P0134 is intermittent, refer to "Intermittents".

Steps 1 To 10:

Steps 11 To 13:

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
1. The On-Board Diagnostic (OBD II) System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
2. During engine warm-up, the O2S 1 should warm up, and its voltage output should vary between 150 mv and 850 mv. When the O2S 1 voltage varies, the engine will go into Closed Loop. This determines if the O2S 1 is operating properly.
4. This will determine if the sensor is malfunctioning or if the wiring or the PCM/ECM is the cause of the DTC P0134.
6. Use only a high impedance digital voltmeter (DVM) for this test. The test checks the continuity of the O2S 1 signal and the ground circuits; if the ground circuit is open, the PCM/ECM voltage on the circuit will be over 0.6 volts (600 mv).
8. The replacement PCM/ECM must be reprogrammed. Refer to Powertrain Control Module / Service and Repair.