P0412

CIRCUIT DESCRIPTION
The secondary air injection (AIR) vacuum control solenoid is used as a switch to direct and control engine vacuum to the AIR shut-off valve.

Voltage is supplied to the AIR solenoid by the ignition 1 voltage circuit. The powertrain control module (PCM) commands the AIR solenoid ON by supplying a ground on the control circuit by an internal switch called a driver. This action completes the circuit and energizes the AIR solenoid allowing vacuum to open the shut-off valve. The PCM driver monitors the control circuit voltage constantly for proper voltage conditions. When the PCM commands the AIR solenoid ON, the circuit voltage should be low, near 0 volts. When the PCM commands the control circuit OFF, the voltage potential of the circuit should be high, near the battery voltage. If the PCM detects a voltage other than what is expected, DTC P0412 sets.

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 control circuit of 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.

TEST DESCRIPTION

Steps 1-4:

Steps 5-8:

Steps 9-15:

Steps 16-17:

The numbers below refer to the step numbers on the diagnostic table.
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.