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Home >> Lexus >> 1991 >> ES 250 Standard >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> Circuit Testing >> Procedure J, Neutral/Start Switch Or Clutch Switch Circuit

Procedure J, Neutral/Start Switch Or Clutch Switch Circuit

NOTE: On automatic transaxle vehicles, begin testing at step 1). On manual transaxle vehicles, begin testing at step 4).
  1. Neutral/Start Switch (Auto. Trans.):  Ensure ignition is off. Disconnect neutral/start switch connector. Check continuity between wiring harness side of neutral/start switch terminal No. 3 and ground. See Figure. If continuity exists, go to next step. If no continuity exists, repair open circuit in wire harness between terminal No. 3 and ground.
  2. Check neutral/start switch operation. Refer to NEUTRAL/START SWITCH TEST  under TESTING. If switch is faulty, replace switch. If switch is okay, reconnect switch and go to next step.
  3. Cruise Control ECU:  Disconnect cruise control ECU connector. With shift lever in Neutral or Park position, check continuity between ECU terminal No. 13 and ground. See Figure. If continuity exists, replace faulty ECU and recheck cruise control system. If no continuity exists, repair open circuit in wire harness between ECU terminal No. 13 and neutral/start switch terminal No. 2. See Figure.
  4. Clutch Switch (Man. Trans.):  Ensure ignition is off. Disconnect clutch switch. Check continuity between wiring harness side of clutch switch terminal No. 2 (Black/Orange wire) and ground. If continuity exists, go to next step. If no continuity exists, repair open circuit in wire harness between clutch switch terminal No. 2 (Black/Orange wire) and ground.
  5. Check clutch switch operation. See CLUTCH SWITCH TEST  under TESTING. If switch is faulty, replace switch. If switch is okay, reconnect switch and go to next step.
  6. Cruise Control ECU:  Disconnect cruise control ECU connector. With clutch pedal fully depressed, check continuity between ECU terminal No. 13 and ground. See Figure. If continuity exists, replace faulty ECU and recheck cruise control system. If no continuity exists, repair open circuit in wire harness between ECU terminal No. 13 and clutch switch terminal No. 1 (Black wire).