DTC P0412: Secondary Air Injection Solenoid Control Circuit: Description

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Pontiac Grand Prix, 2003 Pontiac Bonneville, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, and 2003 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

Ignition voltage is supplied directly to secondary Air Injection (AIR) vacuum control solenoid. Powertrain Control Module (PCM) controls AIR solenoid by grounding control circuit via an internal solid state device called a driver. Primary function of driver is to supply ground for component being controlled. Each driver has a fault line which is monitored by PCM. When PCM is commanding a component on, voltage of control circuit should be about zero volts. When PCM is commanding control circuit to a component off, voltage potential of circuit should be about battery voltage. DTC sets when fault detection circuit senses a voltage other than what is expected. PCM will monitor control circuit for a short to ground, short to voltage, open circuit, open solenoid, internally-shorted or excessively low resistance solenoid. When the PCM detects any of the stated malfunctions, this DTC will set and the affected driver will be disabled.