P0135
DTC P0135
CIRCUIT DESCRIPTION
Heated oxygen sensors (HO2Ss) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by the ignition 1 voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the powertrain control module (PCM). The PCM monitors the current flow through the heater for diagnosis.
If the PCM detects that the HO2S heater current is above or below a specified range, DTC P0135 sets.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0135 HO2S Heater Performance Sensor 1
CONDITIONS FOR RUNNING THE DTC
- DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0128, P0201-P0204, P0300, P0315, P0336, P0442, P0446, P0452, P0453, P0455, P0496, P0506, P0507, P0601, P0602, P1621 are not set.
- The Ignition 1 Signal parameter is between 11-17 volts.
- The ECT Sensor parameter is more than 70°C (158°F).
- The Air Flow Calculated parameter is less than 16 g/s.
- The Fuel Level Sensor parameter is more than 10 percent.
- The Engine Run Time parameter is more than 60 seconds.
- DTC P0135 runs continuously when the above conditions are met.
CONDITIONS FOR SETTING THE DTC
- The PCM detects that the HO2S 1 heater current is less than 0.217 amps or more than 1.56 amps.
- DTC P0135 sets within 200 seconds when the above condition is met.
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
