Release the residual pressure in fuel line (Refer to the Fuel Delivery System - Repair Procedures - "Release Residual Pressure in Fuel Line").
When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of “Release Residual Pressure in Fuel Line” work.
Install the Special Service Tool (SST).
Disconnect the fuel feed tube from the delivery pipe.
There may be some residual pressure even after “Release Residual Pressure in Fuel Line” work, so cover the hose connection with a shop towel to prevent residual fuel from spilling out before disconnecting any fuel connection.
Install the special service tool for measuring the fuel pressure in between the fuel feed tube and the fuel delivery pipe (Refer to the figure below).
Inspect fuel leakage on connections along the fuel feed tube, the delivery pipe, and the SST components with IG ON.
Measure Fuel Pressure.
Start the engine and measure the fuel pressure at idle.
Fuel Pressure: 480 ~ 520 kPa (4.9 ~ 5.3 kgf/cm² , 69.6 ~ 75.4 psi)
If the fuel pressure does not satisfy the standard value, repair or replace the related part. (Refer to the table below.)
Fuel Pressure | Cause | Related Part |
Too Low | Fuel filter clogged | Fuel Filter |
Fuel leakage | Fuel Pressure Regulator | |
Too High | Fuel pressure regulator valve stuck | Fuel Pressure Regulator |
Stop the engine, and then check for the change in the fuel pressure gauge reading.
Standard Value: The gauge reading should hold for about 5 minutes after the engine stops
If the gauge reading should not be held, repair or replace the related part. (Refer to the table below.)
Fuel Pressure (After Engine Stops) | Cause | Related Part |
Fuel Pressure Drops Slowly | Leakage on injector | Injector |
Fuel Pressure Drops Immediately | Check for stuck open fuel pump valve | Fuel Pump |
Turn the ignition switch OFF.
Release the residual pressure in fuel line (Refer to the Fuel Delivery System - Repair Procedures - "Release Residual Pressure in Fuel Line").
When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of “Release Residual Pressure in Fuel Line” work.
Test End
Remove the Special Service Tool (SST) from the fuel feed tube and the delivery pipe.
Connect the fuel feed tube and the delivery pipe.
Whenever the high pressure fuel fuse, fuel pipe, delivery pipe, or injector is removed immediately after shutting off the engine, an injury may be caused by the release of highly pressurized fuel. Release the residual pressure in the high pressure fuel line by referring to the "Residual fuel pressure release procedure" below before removing any high pressure fuel system components.
Wear safety glasses and fuel resistant gloves.
Turn the ignition off and disconnect the battery negative cable.
Remove the fuel pump fuse (A).
Reconnect the battery negative terminal.
Run the engine for about 1 minute to lower the pressure in the low pressure line.
Turn off the engine.
Disconnect the low pressure fuel line quick connector at the High Pressure Pump. Use rags to cover opening and catch spills while removing the fuel line.
Start the engine and let it idle until the engine stops. At this point the pressure should be under 30 psi.
Proceed with the service or repair. Use rags to cover opening and catch spills when opening up the high pressure system.
Reinstall / re-connect all components in reverse order of removal. Start engine and confirm proper operation, and make sure there are no fuel leaks.
After completing, clear DTC(s) using GDS scan tool (the procedure described above will cause DTC to set).
