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 >> Ecu Power Source Circuit Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Ecu Power Source Circuit Test

NOTE: This is power source for ECU and sensors.
  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. Measure voltage (backprobe) between 22-pin ECU connector "A" terminals No. 9 (Blue/White wire) and No. 13 (White/Black wire). See Figure. If battery voltage exists, go to next test listed in SYSTEM TEST INDEX  table. If battery voltage does not exist, go to next step.
  3. Measure resistance (backprobe) between ground and 22-pin ECU connector terminal No. 13 (White/Black wire). If resistance is one ohm or more, repair open ground circuit. If resistance is less than one ohm, go to next step.
  4. Check ECU-B (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