DTC P2457: EGR Cooler "A" Efficiency Below Threshold: Notes

WARNING: This page is about a different variant/trim than selected.

1. -

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling
Poor driving performance

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO (HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

Courtesy of SUBARU OF AMERICA, INC.

CHECK DTC AND FREEZE FRAME DATA .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC other than P2457 displayed? (Current malfunction)

Yes : Check the appropriate DTC using the "Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DO (HEV))>DIAGNOSTIC TROUBLE CODE (DTC) .

No : Go to 2.
CHECK EGR COOLER WATER HOSE .
Check the water hose connected to the EGR cooler. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO (HEV))>EGR COOLER>INSPECTION .

Is the water hose bent?

Yes : After repairing extremely bent sections of the water hose, go to the next step. Go to 3.

No : Go to 4.
CHECK NORMAL RECOVERY .
Perform drive cycle AK. Ref. to ENGINE (DIAGNOSTICS) (H4DO (HEV))>INSPECTION MODE>PROCEDURE>INSPECTION MODE AK .

Is DTC P2457 displayed? (Current malfunction)

Yes : Go to 4.

No : Finish checking.
CHECK EGR COOLER .
Check the water hose and EGR system lines. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO (HEV))>EGR COOLER>INSPECTION .

Is there any dirt, clogging or leak in the water hose or EGR system lines?

Yes : After confirming the following items, clean and securely install the parts.
- Remove dirt or clogging in the water hose.
- Remove dirt in the EGR cooler.
  NOTE: Use parts cleaner for cleaning out dirt in EGR cooler. Perform air blow after cleaning.
No : Replace the EGR cooler, EGR control valve or EGR pipe. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO (HEV))>EGR COOLER . Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO (HEV))>EGR CONTROL VALVE . Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO (HEV))>EGR PIPE .