P0412

CIRCUIT DESCRIPTION
The powertrain control module (PCM) commands the AIR control solenoid ON by grounding the control circuit though an internal switch called a driver. Voltage is supplied to the control solenoid though the ignition 1 voltage circuits and protected by a fuse. When the PCM commands the solenoid ON, the voltage of the control circuit should be low or near 0 volts. When the PCM commands the solenoid OFF, the voltage potential of the circuit should be high, near battery voltage. If the PCM detects a voltage other than what is expected, this DTC will set.

CONDITIONS FOR RUNNING THE DTC
^ The engine is running.
^ The system voltage is between 8-16 volts.

CONDITIONS FOR SETTING THE DTC
^ The PCM detects an improper voltage level on the output circuit that controls the AIR vacuum control solenoid valve.
^ The condition exists for at least 10 seconds.

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/Failure 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
An intermittent may be caused by any of the following conditions:
^ A poor connection
^ Rubbed through wire insulation
^ A broken wire inside the insulation
^ Spread terminal contacts
^ Corroded connections and wiring

The PCM will monitor the control circuit for the following:
^ A short to ground
^ A short to voltage
^ An open circuit
^ An internally shorted or excessively low resistance solenoid

When the PCM detects any of the above malfunctions, this DTC will set and the diagnostic will be disabled.

Thoroughly inspect any circuit that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-9:

Steps 10-17:

The numbers below refer to the step numbers on the diagnostic table.
4. Listen for a click when the solenoid valve operates. Ensure that both the ON and the OFF states are commanded. Repeat the commands as necessary.
6. This step tests for voltage to the AIR solenoid valve.
7. This step verifies that the PCM is providing ground to the AIR solenoid valve.
8. This step tests if a ground is constantly being applied to the AIR solenoid valve.