Repair Procedures

Fuel Pressure Inspection

1. 1
   Release the fuel line residual pressure. (Refer to Fuel System - "Release Fuel Line Residual Pressure")

   A diagnostic trouble code (DTC) may be set when the fuel pump relay is removed. Clear the DTC with GDS after performing "Relieve Residual Fuel Pressure".

2. 2
   Install the Special Service Tool (SST).

   1. Disconnect the fuel supply tube from the high-pressure fuel pump.

      Some residual high pressure may remain even after "Release Residual Fuel Pressure from the Fuel Line." Therefore, cover the connection of the high-pressure line with a cloth or rag to prevent residual fuel from spraying out before removing the pressurized fuel part. Then release the pressure by carefully loosening the connection. Otherwise, injury may result from high fuel temperature and pressure.

   2. Install the special service tool (SST) to measure the fuel pressure between the fuel supply tube and the high-pressure fuel pump (see illustration below).

      

3. 3
   With the ignition switched on, inspect the fuel line and SST connections for leaks.
4. 4
   Measure the fuel pressure.

   1. Start the engine and measure the fuel pressure at idle. Fuel pressure: 343 ~ 598 kPa (3.5 ~ 6.1 kgf/cm², 49.8 ~ 86.7 psi)

      If the fuel pressure differs from the specified value, repair or replace the relevant part.

   2. Stop the engine, then check the change in the fuel pressure gauge reading. Specified value: The gauge reading must be maintained for approximately 5 minutes after the engine is stopped.

      If the gauge reading is not maintained, repair or replace the relevant part (see table below).

      Fuel Pressure (After Engine Stop)	Cause	Related Part
      Fuel pressure drops slowly	Injector leakage	Injector
      Fuel pressure drops immediately	Fuel pump check valve stuck open	Fuel pump

   3. Turn the ignition off.
5. 5
   Release the fuel line residual pressure. (Refer to Fuel System - "Release Fuel Line Residual Pressure")

   A diagnostic trouble code (DTC) may be set when the fuel pump relay is removed. Clear the DTC with GDS after performing "Relieve Residual Fuel Pressure".

6. 6
   End of test

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

Release Fuel Line Residual Pressure

Whenever the high-pressure fuel pump, fuel rail, feed pipe or injector is removed immediately after the engine has been stopped, injury may be caused by fuel spraying out under high pressure. To release the residual pressure in the high-pressure fuel line, refer to the "Fuel Residual Pressure Release Procedure" below before removing the fuel system high-pressure components.

Wear protective goggles and fuel-resistant gloves.

1. 1
   Turn the ignition OFF 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 relay.
4. 4
   Connect the negative battery cable.
5. 5
   Start the engine and let it run for approximately 20 seconds to reduce the pressure in both the high-pressure and low-pressure lines. The engine may stall within the 20-second period. If it does not, turn the engine OFF.
6. 6
   Continue with service or repair. Use a cloth to cover the opening and catch any spilled fuel when opening the high-pressure system.
7. 7
   Reinstall/reconnect all components in the reverse order of removal. Start the engine and verify proper operation, and make sure there are no fuel leaks.
8. 8
   After completion, erase the DTCs using the GDS diagnostic scan tool (the procedure described above will set DTCs).