Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Lexus >> 1998 >> SC 400 >> Repair and Diagnosis >> Brakes >> Traction Control >> Traction Control System >> Circuit Tests >> TRAC Off Indicator, TRAC Cut Switch Circuit >> Diagnosis & Repair

Diagnosis & Repair

  1. Determine if any ABS DTCs are present. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Repair as needed. If no DTCs exist, go to next step.
  2. Remove TRAC cut switch. Disconnect harness connector. Check continuity between terminals No. 2 and 3 (LS400), No. 2 and 6 (SC300, SC400) or No. 1 and 2 (GS300) on switch connector. See Fig 1 or Figure. Continuity should only exist when switch button is pressed. Replace switch as needed. If switch is okay, go to next step.
  3. Check continuity of CSW circuit between TRAC cut switch and ABS/TRAC ECU. Repair as needed. If circuit is okay, go to next step.
  4. Inspect TRAC OFF indicator light. Replace as needed. If light is okay, go to next step.
  5. Check continuity of WT circuit between TRAC OFF indicator light and ABS/TRAC ECU. Repair as needed. If circuit is okay, replace ABS/TRAC ECU.
Fig 1: Identifying TRAC Cut Switch Terminals (LS400)
G96B20603Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Identifying TRAC Cut Switch Terminals (SC300, SC400)
G98J12939Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
scientia non olet · About Mike's Workshop Manuals