P0036
DTC P0030 or P0036
Circuit Description
Heated oxygen sensors (HO2S) 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 commands the heater ON or OFF to maintain a specific HO2S operating temperature range. The PCM monitors the voltage on the HO2S heater low control circuit for heater fault diagnosis. If the PCM detects that the HO2S heater low control circuit voltage is not within a specified range, DTC P0030 sets for HO2S 1, or DTC P0036 sets for HO2S 2.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
* DTC P0030 HO2S Heater Control Circuit Sensor 1
* DTC P0036 HO2S Heater Control Circuit Sensor 2
Conditions for Running the DTC
* The Ignition 1 Signal parameter is between 11-18 volts.
* The engine speed is more than 450 RPM.
* DTC P0030 or P0036 run continuously when the above conditions are met.
Conditions for Setting the DTC
* The PCM detects that the affected HO2S heater low control circuit voltage is not within a specified range.
* DTC P0030 or P0036 sets within 3 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
