1.Release the residual pressure in fuel line.(Refer to Fuel Delivery System - "Release Residual Pressure in Fuel Line")
• When removing the fuel pump relay, the Diagnostic Trouble Code (DTC) will be occurred. Therefore delete the code with the diagnostic tool after "Release Residual Pressure in Fuel Line" work.
2.Install the Special Service Tool (SST).
(1)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.
(2)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).

3.Inspect fuel leakage on connections among the fuel feed tube, the delivery pipe, and the SST components with IG ON.
4. Measure Fuel Pressure
(1)Start the engine and measure the fuel pressure at idle.
Fuel Pressure : 480 - 520 kPa (4.9 - 5.3 kgf/cm, 69.6 - 75.4 psi)
• If the fuel pressure differs from 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 |
(2)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 valve of fuel pump open stuck | Fuel Pump |
(3)Turn the ignition switch OFF.
5.Release the residual pressure in fuel line.(Refer to Fuel Delivery System - "Release Residual Pressure in Fuel Line")
• When removing the fuel pump relay, the Diagnostic Trouble Code (DTC) will be occurred. Therefore delete the code with the diagnostic tool after "Release Residual Pressure in Fuel Line" work.
6.Test End
(1)Remove the Special Service Tool (SST) from the fuel feed tube ant the delivery pipe.
(2)Connect the fuel feed tube and the delivery pipe.
Components and Components Location
Release Residual Pressure in Fuel LineHyundai Tucson (NX4) 2022-2026 Service Manual: Special Service Tools
- Special Service Tools
Tool (Number and Name)IllustrationApplication
RKE Battery Checker(09954-2P100)
Measuring the RKE battery voltage.
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Hyundai Tucson (NX4) 2022-2026 Owner's Manual: Slide Open/Close
Push the sunroof switch rearward.
The sunroof glass slides open. If the
power sunshade is closed, the power
sunshade opens first and then the
sunroof glass opens.
Push the sunroof switch forward. The
sunroof glass closes.
Push the sunroof switch forward or
rearward to th ...