Checking Fuel Pump Operation Using Scan Tool (GS300, GS430, GX470, IS300 & LS430)
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2003 Lexus SC 430, 2003 Lexus RX 300, 2003 Lexus LX 470, 2003 Lexus LS 430, and 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
- Connect scan tool to Data Link Connector (DLC) No. 3, located under left side of instrument panel. Turn ignition on. DO NOT start engine.
- Turn scan tool on. Select ACTIVE TEST mode on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. On GS300, GX470 and IS300, listen for fuel pump operating sound and check that screw at center of fuel pressure pulsation damper moves upward due to fuel pressure. See Fig 1. Fuel pulsation damper is located at firewall end of fuel rail. On all other models, listen for fuel pump operating sound and feel for fuel pressure in fuel inlet hose.
- On all models, turn ignition off. Remove scan tool. If fuel pump operates, check fuel pressure. See FUEL PRESSURE . If fuel pump does not operate, check for defective fusible links/fuses. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If fusible links/fuses are okay, go to next step.
- Check for defective fuel pump. See CHECKING FUEL PUMP OPERATION BY APPLYING BATTERY VOLTAGE TO FUEL PUMP . Replace fuel pump as necessary and retest. If fuel pump operates, check fuel pump control circuit. See FUEL DELIVERY under FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article.