LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2000 >> GS 400 >> Repair and Diagnosis >> Engine Performance >> Engine Controls - On-Vehicle Adjustments >> Ignition Timing >> GS400
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Ignition Timing: GS400

  1. Remove intake manifold cover located on top of engine, above intake manifold. Start engine and warm engine to normal operating temperature. Shut engine off. Connect scan tool to data link connector No. 3. See Figure. Scan tool is used to read engine RPM.
  2. Connect timing light lead to Yellow wire at ignition coil electrical connector on top of driver's side valve cover at cylinder No. 1. See Fig 1. Cylinder No. 1 is front cylinder on left side of engine when viewed from flywheel end of engine. See Figure.
  3. Install Jumper Wire (SST 09843-18020) between terminals TC and E1 on data link connector No. 1. See Fig 2. Data link connector is located near driver's side strut tower. Apply parking brake. Place transmission in Neutral. Start engine and allow engine to idle.
  4. Timing marks are located on timing belt cover, near crankshaft pulley. Ensure base timing is 8-12 degrees BTDC at idle with transmission in Neutral, and with A/C and all accessories off. Shut engine off. Remove jumper wire, timing light and scan tool. Reinstall intake manifold cover.
    Fig 1: Connecting Timing Light At Ignition Coil (GS400)
    G99B50428Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Installing Jumper Wire Between Data Link Connector No. 1 Terminals (GS400)
    G99A50419Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002