P0135
DTC P0135CIRCUIT DESCRIPTION
Heating elements inside the heated oxygen sensors (HO2S) minimize the time required for the sensors to reach operating temperature, and to provide an accurate voltage signal. The HO2S heater operation is controlled by the powertrain control module (PCM). Each HO2S is supplied power from the external ignition 1 voltage circuit. The PCM controls each HO2S heater low control circuit with a low side driver. The HO2S heater diagnostic monitors the current draw through the low side driver when the engine is running. If the PCM detects that the HO2S current parameter is out of range for a longer than expected period of time, the following DTCs will set:
- P0135 for Bank 1 Sensor 1
- P0141 for Bank 1 Sensor 2
- P0155 for Bank 2 Sensor 1
CONDITIONS FOR RUNNING THE DTC
- DTCs P0030, P0036, or P0050 are not set.
- The ECT Sensor parameter is more than 60°C (140°F).
- The Engine Speed parameter is between 500-3,000 RPM.
- The Engine Run Time parameter is more than 3 minutes.
- The MAF parameter is between 5-30 g/s.
- All of the above conditions are met for 2 seconds.
CONDITIONS FOR SETTING THE DTC
For DTC P0135 or P0155, the PCM detects that the affected HO2S heater current value is less than 0.25 A or more than 3.12 A for more than 8 seconds.
OR
For DTC P0141, the PCM detects that the affected HO2S heater current value is less than 0.20 A or more than 0.91 A for more than 8 seconds.
ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.
TEST
