DTC P2433: Secondary Air System Air Flow/Pressure Sensor Circuit High Bank 1: Notes

DTC detecting condition: 

Immediately at fault recognition

Wiring diagram: 

Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK CURRENT DATA. 
   1. Turn the ignition switch to ON.
   2. Read the value of «Sec. Air Piping Pressure» using Subaru Select Monitor.
   NOTE: For detailed operation procedures, refer to "Read Current Data For Engine". Refer to ENGINE (DIAGNOSTICS) (STI)>SUBARU SELECT MONITOR .

   Is the value of «Sec. Air Piping Pressure» 133.3 kPa (1, 000 mmHg, 39.4 inHg) or more?

   Yes:  Go to  2.

   No:  Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2. CHECK HARNESS BETWEEN ECM AND SECONDARY AIR COMBINATION VALVE CONNECTOR. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the secondary air combination valve LH.
   3. Turn the ignition switch to ON.
   4. Read the value of «Sec. Air Piping Pressure» using Subaru Select Monitor.
   NOTE: For detailed operation procedures, refer to "Read Current Data For Engine". Refer to ENGINE (DIAGNOSTICS) (STI)>SUBARU SELECT MONITOR .

   Is the value of «Sec. Air Piping Pressure» 133.3 kPa (1, 000 mmHg, 39.4 inHg) or more?

   Yes:  Repair the short circuit to power in harness between ECM connector and secondary air combination valve LH connector.

   No:  Go to  3.

3. CHECK HARNESS BETWEEN ECM AND SECONDARY AIR COMBINATION VALVE CONNECTOR. 
   1. Turn the ignition switch to OFF.
   2. Measure the resistance of the harness between the secondary air combination valve LH connector and engine ground.

   Connector & terminal 

   (E40) No. 3 - Engine ground:

   Is the resistance less than 5 Ω?

   Yes:  Go to  4.

   No:  Repair the harness and connector.

   NOTE: In this case, repair the following item:

   • Open circuit in harness between ECM connector and secondary air combination valve LH connector
   • Poor contact of ECM connector
   • Poor contact of coupling connector
4. CHECK FOR POOR CONTACT. 

   Check for poor contact of the secondary air combination valve LH connector.

   Is there poor contact of the secondary air combination valve LH connector?

   Yes:  Repair the poor contact of the secondary air combination valve LH connector.

   No:  Replace the secondary air combination valve LH. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (STI)>SECONDARY AIR COMBINATION VALVE .