Repair Procedures

Fuel Pressure Inspection (Low-Pressure System)

1. 1
   Release the residual pressure in the fuel line. (Refer to Fuel System - Repair Procedures - Releasing Residual Pressure in the Fuel Line)
2. 2
   Install the Special Service Tool (SST).

   1. Disconnect the low-pressure fuel supply hose from the low-pressure inlet of the high-pressure fuel pump.
   2. Install the special service tool (SST) fuel pressure gauge between the low-pressure fuel supply pipe and the low-pressure inlet of the high-pressure fuel pump (See illustration below).

      

3. 3
   Check that there are no fuel leaks at the low-pressure fuel supply pipe connections, the low-pressure inlet of the high-pressure fuel pump, and the SST components.
4. 4
   Measure the fuel pressure.

   1. Start the engine and measure the fuel pressure at idle. Fuel pressure: 495 – 505 kPa (4.9 – 5.1 kgf/cm², 71.8 – 73.2 psi)

      FUEL PRESSURE	Cause	Related Parts
      Too low	Clogged fuel filter	Fuel filter
      	Fuel leakage	Fuel Pressure Regulator
      Too high	Fuel pressure regulator stuck	Fuel Pressure Regulator

   2. Turn the engine OFF and check whether the fuel pressure gauge display has changed. STANDARD VALUE: When the engine is off, the Fuel Level indicator remains displayed for approx. 5 minutes.

      fuel pressure (After engine stop)	Cause	Connected PIECE
      Fuel pressure decreases slowly	Injector leakage	INJECTOR
      Fuel pressure drops immediately	Check whether the fuel pump check valve is blocked	Fuel pump

   3. Turn the ignition switch to the OFF position.
5. 5
   Release the residual pressure in the fuel line. (Refer to Fuel System - Repair Procedures - Releasing Residual Pressure in the Fuel Line)
6. 6
   End of test

   1. Remove the special service tool (SST) from the low-pressure fuel pipe and the low-pressure inlet of the high-pressure fuel pump.
   2. Connect the low-pressure fuel supply pipe to the low-pressure inlet of the high-pressure fuel pump.

Fuel Line Residual Pressure Release

1. 1
   Turn the ignition switch to the OFF position and disconnect the negative battery cable.
2. 2
   Remove the fuel pump fuse (A).

   

3. 3
   Disconnect the electrical connector from the high-pressure fuel pump.
4. 4
   Connect the battery negative cable.
5. 5
   Run the engine for approximately 20 seconds to reduce the pressure in the high- or low-pressure line. The engine should stop after 20 seconds. Otherwise, turn the engine off.
6. 6
   Perform maintenance or repair. Use rags to cover the opening and wipe up any spills when opening a high-pressure system.
7. 7
   Install/connect all removed parts in the reverse order of removal. Start the engine and check for proper operation and make sure there are no fuel leaks.
8. 8
   After completion, erase the DTCs using the GDS diagnostic tool (the above procedure sets a fault code).