DTC P2431: Secondary Air System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1: Notes

DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode Refer to ENGINE (DIAGNOSTICS) (STI)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Refer to ENGINE (DIAGNOSTICS) (STI)>INSPECTION MODE>PROCEDURE .

CHECK DTC.
Read the engine DTC using the Subaru Select Monitor or general scan tool. Refer to ENGINE (DIAGNOSTICS) (STI)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC other than P2431 displayed? (Current malfunction)

Yes: Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer to ENGINE (DIAGNOSTICS) (STI)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

No: Go to 2.
CHECK CURRENT DATA.
1. Turn the ignition switch to ON (engine OFF).
2. Using the Subaru Select Monitor, read the values in «Sec. Air Piping Pressure*, «Mani. Absolute Pressure* and «Atmosphere Pressure*, and compare them with actual atmospheric pressure.
  NOTE: For detailed operation procedures, refer to "Read Current Data For Engine". Refer to ENGINE (DIAGNOSTICS) (STI)>SUBARU SELECT MONITOR .
Does the displayed value differ from the actual atmospheric pressure by 200 mmHg (27 kPa, 8 inHg, 3.9 psig) or more?

Yes: Replace the secondary air combination valve (with built-in pressure sensor). Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (STI)>SECONDARY AIR COMBINATION VALVE .

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.