Possible causes

– Short in Air Pump circuit
– Air pump assembly
– Faulty Pressure Sensor
– Pressure Sensor harness is open or shorted
– Pressure Sensor circuit poor electrical connection

When is the code detected?

If the pressure level from the sensor has not reached a certain level despite the ECM turning on the air pump,or if the pressure level exceeds the threshold despite the ECM turning off the air pump, the ECM interprets this as a fault in the secondary air injection system and the code is set.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P2444 ISUZU Description

To accelerate the activation of catalyst when warming up the engine, the air injection system pumps the secondary air to the exhaust manifold by pressure. The secondary air is supplied by the air pump and it is pumped to the exhaust manifold through the air switching valve. Open and close movement of the air switching valve is regulated by the Vacuum Switching Valve (VSV).The air pump and the air switching valve are observed by the Engine Control Module (ECM) and are used to detect malfunction in this system. The ECM monitors the secondary air injection system and detects malfunction using a pressure sensor located on the air switching valve.

The ECM observes the pressure in the secondary air passage using the pressure sensor located on the air switching valve in the secondary air injection system. The sensor detects an exhaust pressure in the secondary air passage.