Monitor Description

When the air injection system operation is required while the engine is warming up, the ECM transmits command signals to the Air Injection Control Driver (AID) to drive the air pump and Air Switching Valve (ASV).

AID detects an open and short in the air pump and air switching valve circuit according to the terminal voltage and sends a signal as the diagnostic information to the ECM.

If the air injection system drive circuit or the AID itself has a malfunction, the AID sends a malfunction signal (duty signal) as a diagnostic information signal to the ECM (when the system is normal, a system normal signal is sent).

The ECM sets the DTC based on the diagnostic information from the AID.

Example:

1. The duty ratio of the diagnostic information signal output from AID is 0 or 100 % (remains at 0 V or battery voltage).
2. The duty ratio of the diagnostic signal from the AID shows an impossible ratio (other than 0, 20,40, 60, 80, 100 %).
3. The AID outputs the normal signal (normal duty signal: 80 %) while the system is not operating.