Engine Control System (Diagnostics) (2 Of 2)

ECM supplies a voltage of 5 V to some of the sensors systematically divided into 3 groups, respectively. Accordingly, when a short circuit develops in a sensor power source, a malfunction may occur simultaneously in the sensors belonging to the same group as the short-circuited sensor.

1. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT-1 
   1. Turn ignition switch OFF.
   2. Disconnect EVAP control system pressure sensor harness connector.
   3. Turn ignition switch ON.
   4. Check the voltage between EVAP control system pressure sensor harness connector and ground.

      +		-	Voltage (Approx.)
      EVAP control system pressure sensor
      Connector	Terminal
      C17	3	Ground	5 V

   Is the inspection result normal?

   YES

   INSPECTION END

   NO

   GO TO 2.

2. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT-2 
   1. Turn ignition switch OFF.
   2. Disconnect ECM harness connector.
   3. Check the continuity between EVAP control system pressure sensor harness connector and ECM harness connector.

      +		-		Continuity
      EVAP control system pressure sensor		ECM
      Connector	Terminal	Connector	Terminal
      C17	3	E20	125	Existed

   Is the inspection result normal?

   YES

   GO TO 3.

   NO

   Repair open circuit.

3. CHECK SENSOR POWER SUPPLY 3 CIRCUIT 
   1. Disconnect following sensors harness connector.
   2. Check harness for short to power and short to ground, between the following terminals.

   ECM		Sensor
   Connector	Terminal	Name	Connector	Terminal
   E20	125	EVAP control system pressure sensor	C17	3
   F91	29	Fuel rail pressure sensor	F26	1
   		Engine oil pressure sensor	E220	3
   		Refrigerant pressure sensor	E77	1
   		Power steering pressure sensor	F35	1

   Is the inspection result normal?

   YES

   GO TO 4.

   NO

   Repair short to ground or short to power in harness or connectors.

4. CHECK COMPONENTS 

   Check the following.

   • EVAP control system pressure sensor (Refer to Component Inspection ).
   • Fuel rail pressure sensor (Refer to Component Inspection ).
   • Engine oil pressure sensor (Refer to Component Inspection ).
   • Refrigerant pressure sensor (Refer to Component Function Check ).
   • Power steering pressure sensor (Refer to Component Inspection ).

   Is the inspection result normal?

   YES

   Refer to Inspection .

   NO

   Replace malfunctioning component.