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 Ref. to ENGINE (DIAGNOSTICS) (STI)>Clear Memory Mode>OPERATION , and inspection mode Ref. to ENGINE (DIAGNOSTICS) (STI)>Inspection Mode>PROCEDURE .

CHECK DTC .
Read the engine DTC using the Subaru Select Monitor or general scan tool. Ref. 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)". Ref. 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". Ref. 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). Ref. 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.