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Manual Switch Circuit

  1. Turn ignition off. Remove tilt and telescopic ECU with wiring harness connector attached. Using a voltmeter, measure voltage by backprobing rear of 18-pin ECU connector T10 between terminals No. 17 (Red/White wire) and No. 16 (Violet wire). See Figure. Operate manual switch in each position and note voltage reading. See MANUAL SWITCH CIRCUIT VOLTAGE  table. If voltage is not as specified, go to next step. If voltage is as specified, go to next test listed in SYMPTOM DIAGNOSIS  table under TROUBLE SHOOTING.
    MANUAL SWITCH CIRCUIT VOLTAGE

    Switch Position Voltage
    Telescopic Extend 2.05-2.75
    Telescopic Retract .65-.95
    Tilt Down .30-.50
    Tilt Up 1.30-1.70
  2. Disconnect 18-pin tilt and power telescopic unit (combination switch) connector. Using an ohmmeter, measure resistance between tilt and power telescopic unit (combination switch) connector terminals No. 4 (Red/White wire) and No. 6 (Violet wire). See Fig 1. Operate manual switch in each position and note resistance reading. See MANUAL SWITCH RESISTANCE  table. If resistance is as specified, go to next step. If resistance is not as specified, replace tilt and power telescopic unit (combination switch) and retest system operation.
    MANUAL SWITCH RESISTANCE

    Switch Position Ohms
    Telescopic Extend 160
    Telescopic Retract 790
    Tilt Down 1,990
    Tilt Up 360
  3. Check wiring harness and connectors between tilt and telescopic ECU and tilt and power telescopic unit (combination switch). See WIRING DIAGRAMS . Repair or replace as necessary. If wiring harness and connectors are okay, check tilt and telescopic ECU. See TILT & TELESCOPIC ECU PIN VOLTAGE TESTS  under COMPONENT TESTS. Replace tilt and telescopic ECU as necessary and retest system operation.
Fig 1: Testing Manual Switch
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