P0135
DTC P0135
CIRCUIT DESCRIPTION
Heating elements inside the heated oxygen sensor (HO2S) minimize the time required for the sensors to reach operating temperature and provide an accurate voltage signal. A low side driver within the engine control module (ECM) is pulse width controlled to provide current to the heater elements. The ECM will not allow continuous HO2S heating until calibrated limits of time, temperature, and intake airflow have been reached. The ECM will observe the activity of HO2S to determine if it has become active within a certain time period, after start-up. If the sensor has not become active within an expected time period, after start-up, the ECM will force a rich and lean state and wait for a response from the sensor. If the sensor still does not respond, a failure is reported and DTC P0135 or DTC P0155 will set. If the sensor is active within an expected time period, after engine start-up, the ECM will wait a calibrated amount of time and then begin calculating the temperature of the sensor. If the temperature of the sensor moves outside a calibrated range, a failure counter is incremented. If the number of failures exceed a calibrated amount, DTC P0135 will set for bank 1 sensor 1 or DTC P0155 will set for bank 2 sensor 1. A small reference voltage of approximately 4.5 volts is present at the heater low control circuit.
DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- DTC P1035 HO2S Heater Performance Bank 1 Sensor 1
- DTC P1055 HO2S Heater Performance Bank 2 Sensor 1
CONDITIONS FOR RUNNING THE DTC
- DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0101, P0102, P0103, P0106, P0107, P0108, P0131, P0132, P0133, P0135, P0137, P0138, P0139, P0140, P0141, P0151, P0152, P0153, P0155, P0157, P0158, P0159, P0160, P0161, P1137, P1138, P1157, P1158, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, P2629, are not set.
- The engine is running.
- The ignition 1 signal parameter is more than 10 volts.
- The HO2S Heater Bn 1 Sen. 1 or HO2S Heater Bn 2 Sen. 1 is more than 14.8 percent.
- The battery voltage is more than 10 volts.
- DTC P0135 or P0155 runs continuously once the above conditions are met.
CONDITIONS FOR SETTING THE DTC
- The HO2S has not shown the proper activity after a forced lean or rich state has been commanded for more than 25 seconds duration. OR
- The HO2S shows the proper activity, but the calculated temperature of the HO2S falls below 600°C (1,112°F) or exceeds 900°C (1,652°F), during 28 of 32 samples.
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
