P0135
DTC P0135
CIRCUIT 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 measures the current flow through the low side driver when the engine is running. The PCM will also use the measured current flow, during operation and during engine start-up, to calculate the resistance of the HO2S heater. Based on the resistance, the PCM can predict the temperature of the HO2S heater. If the PCM detects that the HO2S current parameter is out of range for a longer than expected period of time, or if the PCM detects that the calculated HO2S heater resistance is out of range during a cold start, the following DTCs will set:
- P0135 for Bank 1 Sensor 1
- P0141 for Bank 1 Sensor 2
- P0155 for Bank 2 Sensor 1
DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- DTC P0135 HO2S Heater Performance Bank 1 Sensor 1
- DTC P0141 HO2S Heater Performance Bank 1 Sensor 2
- DTC P0155 HO2S Heater Performance Bank 2 Sensor 1
CONDITIONS FOR RUNNING THE DTC
Heater Current Test
- DTCs P0030, P0036, 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.
- DTCs P0135, P0141, and P0155 run 5 tests per key cycle with a 120 second delay between tests once the above conditions are met.
Heater Resistance Test
- DTCs P0030, P0036, P0050 are not set.
- The ignition is OFF for more than 8 hours.
- The ECT Sensor parameter is between -30 to +45°C (-22 to +113°F).
- The difference between the ECT Sensor parameter and the IAT Sensor parameter is less than 8°C (14.4°F).
- The engine is running.
- DTCs P0135, P0141, and P0155 run 5 tests per key cycle with a 120 second delay between tests once the above conditions are met.
CONDITIONS FOR SETTING THE DTC
Heater Current Test
- For DTC P0135 or P0155, the PCM detects that the affected HO2S heater current value is less than 0.25 amps or more than 3.12 amps for more than 8 seconds.OR
- For DTC P0141, the PCM detects that the affected HO2S heater current value is less than 0.20 amps or more than 0.91 amps for more than 8 seconds.
Heater Resistance Test
The PCM detects that the affected HO2S heater calculated resistance is not within an expected range at engine start-up.
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
