P0030

CIRCUIT DESCRIPTION
The Heated Oxygen Sensor (HO2S) heater is a device used to reduce the time that the sensor takes to go active. The Powertrain Control Module (PCM) uses a high side driver in order to apply ignition voltage to the bank 1 sensor 1 heater, and uses a low side driver (ODM) in order 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, the Diagnostic Trouble Code (DTC) will set.

CONDITIONS FOR RUNNING THE DTC
The 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 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.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS

NOTE: Use the connector test adapter kit J 35616-A for any test that requires probing the following items:
^ The PCM harness connectors
^ The electrical center fuse/relay cavities
^ The component terminals
^ The component harness connector

Using this kit will prevent damage caused by the improper probing of connector terminals.

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

TEST DESCRIPTION

Steps 1-10:

Steps 11-19:

The numbers below refer to the step numbers on the diagnostic table.
3. This step isolates the condition. If all DTCs are set, one of the heater low circuits is grounded. An internal HO2S condition can also cause all DTCs to set.
4. This step determines if the bank 1 sensor 1 heater high circuit is shorted to a ground.
8. The bank 1 sensor 1 and the 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.