P0491, P0492 SECONDARY AIR INJECTION SYSTEM

VR38

P0491 P0492

DTC Logic

DTC DETECTION LOGIC

DTC No.	Trouble diagnosis name	DTC detecting condition	Possible cause
P0491	Secondary air injection system insufficient flow (bank 1)	Though the secondary air injection system is operating, the secondary airflow to the exhaust port is too small.	Harness or connectors (Air cut solenoid valve circuit is open or shorted) (Air cut solenoid valve relay circuit is open or shorted) Air cut solenoid valve Air cut solenoid valve relay Disconnection, clogging, collapsing and damage of hose or piping
P0492	Secondary air injection system insufficient flow (bank 2)

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

2.PERFORM DTC CONFIRMATION PROCEDURE

1.CHECK HOSE AND PIPING

2.CHECK AIR CUT SOLENOID VALVE RELAY POWER SUPPLY CIRCUIT-I

3.DETECT MALFUNCTIONING PART

4.CHECK AIR CUT SOLENOID VALVE RELAY POWER SUPPLY CIRCUIT-II

5.DETECT MALFUNCTIONING PART

6.CHECK AIR CUT SOLENOID VALVE RELAY

7.CHECK AIR CUT SOLENOID VALVE POWER SUPPLY CIRCUIT

8.DETECT MALFUNCTIONING PART

9.CHECK AIR CUT SOLENOID VALVE GROUND CIRCUIT FOR OPEN AND SHORT

10.CHECK AIR CUT SOLENOID VALVE

11.CHECK INTERMITTENT INCIDENT