System Description

WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

The DTC P2433 secondary air injection (AIR) system pressure sensor circuit high voltage diagnostic monitors the circuit for a high voltage. The AIR system aids in the reduction of hydrocarbon emissions during a cold start. The system forces fresh filtered air into the exhaust stream in order to accelerate the catalyst operation. An electric air pump, the AIR pump, provides filtered air on demand to the AIR control solenoid valve/pressure sensor assembly. The AIR control solenoid valve/pressure sensor assembly controls the flow of air from the AIR pump to the exhaust manifold. The AIR valve relay supplies the current needed to operate the AIR control solenoid valve/pressure sensor assembly. A pressure sensor is used to monitor the air flow from the AIR pump. The powertrain control module (PCM) supplies the internal pressure sensor with a 5-volt reference, an electrical ground and a signal circuit. By comparing the measured pressure against the expected pressure, the PCM can detect faults in the AIR pump, the AIR control/shut-off valve and the exhaust check valve. The pressure sensor can also detect leaks in the AIR system plumbing.