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Manual Switch Circuit

  1. Remove tilt and telescopic control module and leave harness connectors connected. Measure voltage between tilt and telescopic control module connector T10, terminals No. 16 and No. 17. See Figure. Operate manual switch in each position and note voltage reading. See MANUAL SWITCH OPERATION PIN VOLTAGE  table. If voltages are as specified, go to TROUBLE SHOOTING  and identify next circuit to be checked. If voltages are not as specified, go to next step.
    MANUAL SWITCH OPERATION PIN VOLTAGE

    Switch Position (1) Voltage
    Telescopic Retract 2.6
    Tilt Up 3.5
    Telescopic Extend 4.2
    Tilt Down 4.6
    (1) Approximate measured voltage.
  2. Disconnect manual switch wiring harness connector. On SC300 models, measure resistance between manual switch connector terminals No. 4 and No. 6. On SC400 models, measure resistance between manual switch connector terminals No. 3 and No. 5. See Fig 1 and Fig 2. Operate manual switch in each position and note resistance. See MANUAL SWITCH RESISTANCE  table. If resistances are as specified, go to next step. If resistances are not as specified, replace tilt and telescopic manual switch.
    MANUAL SWITCH RESISTANCE

    Switch Position Ohms
    Telescopic Extend 160
    Tilt Up 360
    Telescopic Retract 790
    Tilt Down 1990
    Fig 1: Testing Manual Switch (SC300 Models)
    G97H08071Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Testing Manual Switch (SC400 Models)
    G97J08072Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Check and repair wiring harness between tilt and telescopic control module and manual switch connector. See WIRING DIAGRAMS . If wiring harness is okay, replace tilt and telescopic control module and retest system.