P0030

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Engine Controls Schematics: Heated Oxygen Sensors:

CIRCUIT DESCRIPTION
The oxygen sensor heater is a device used to reduce the time that the sensor takes to go active. The PCM uses a high side driver to apply ignition voltage to bank 1 sensor 1 heater, and a low side driver (ODM) to supply the ground path. The PCM monitors the high side driver for circuit conditions that are incorrect for the commanded state of the driver. If the PCM detects an improper circuit condition in the high side driver, DTC P0030 will set.

CONDITIONS FOR RUNNING THE DTC
System voltage is between 9-18 volts.

CONDITIONS FOR SETTING THE DTC
The PCM detects an incorrect circuit condition in the high side driver for HO2S bank 1 sensor 1.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
^ The PCM stores the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions in Symptoms. Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step isolates the condition. If all three DTCs are set, this indicates that one of the heater low circuits are grounded. An internal HO2S condition can also cause all three DTCs to set.
3. This step determines if the bank 1 sensor 1 heater high circuit is shorted to a ground.
7. The bank 1 sensor 1 and bank 2 sensor 1 are internally connected within the PCM. If the voltage measurement is within the specified range, the bank 2 sensor 1 is causing the condition.