DTC P1499: Coil 4 EGR "A" Control Circuit High: Notes

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling
Poor driving performance
Engine breathing

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

G13202559

Courtesy of SUBARU OF AMERICA, INC.

CHECK HARNESS BETWEEN ECM AND EGR CONTROL VALVE CONNECTOR (SHORT TO POWER SUPPLY).
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the EGR control valve.
4. Turn the ignition switch to ON.
5. Measure the voltage between ECM connector and engine ground.
  Connector and terminal.
  
  DTC P1493; (E158) No. 25 (+) - Engine ground (-):
  
  DTC P1495; (E158) No. 51 (+) - Engine ground (-):
  
  DTC P1497; (E158) No. 38 (+) - Engine ground (-):
  
  DTC P1499; (E158) No. 64 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes : Repair the short circuit to power supply in the harness between the ECM connector and EGR control valve connector.

No : Go to 2.
CHECK EGR CONTROL VALVE.
Measure the resistance between EGR control valve terminals.

Terminals

DTC P1493; No. 2 - No. 3:

DTC P1495; No. 2 - No. 1:

DTC P1497; No. 5 - No. 4:

DTC P1499; No. 5 - No. 6:

Is the resistance 20 Ω or more?

Yes : Repair the poor contact of ECM connector.

No : Replace EGR control valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DOTC)>EGR CONTROL VALVE .