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

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM .

Fig 1: Engine Electrical System Wiring Diagram (EGR Control Circuit High)

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK HARNESS BETWEEN ECM AND EGR CONTROL VALVE CONNECTOR  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the EGR control valve.
   3. Disconnect the connector from ECM.
   4. Turn the ignition switch to ON.
   5. Measure the voltage between ECM connector and chassis ground.

   Connector & terminal 

   DTC P1493; (B135) No. 12 (+) - Chassis ground (-):

   DTC P1495; (B135) No. 48 (+) - Chassis ground (-):

   DTC P1497; (B135) No. 25 (+) - Chassis ground (-):

   DTC P1499; (B135) No. 49 (+) - Chassis 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.
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) (H4DO)>EGR Control Valve .