LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 1998 >> LX 470 >> Repair and Diagnosis >> Body & Frame >> Seats >> Seats - Power W/Memory >> System Tests >> Ignition Switch Circuit Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Ignition Switch Circuit Test

NOTE: This circuit sends ignition ON/OFF signal to ECU.
  1. At driver's seat, remove bolts for front vertical adjuster. Lift front end of seat cushion slightly for access to power seat ECU. Remove power seat ECU, but leave wiring harness connectors attached.
  2. Check voltage (backprobe) between 22-pin ECU connector "A" terminals No. 8 (Black/White wire) and ground. See Figure. No voltage should exist. Turn ignition on. Battery voltage should exist. If voltage is as specified, go to next test listed in SYSTEM TEST INDEX  table. If voltage does not exist, go to next step.
  3. Check ECU-IG (15-amp) fuse in instrument panel junction block. If fuse is faulty, repair short in wiring between fuse and ECU. Replace fuse. If fuse is okay, diagnose and repair open circuit between fuse and ECU. See WIRING DIAGRAMS .
scientia non olet · About LEMON Manuals