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GS300 & SC300

  1. Remove ignition coils. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Reconnect electrical connectors on ignition coils.
  2. Remove spark plugs. Install spark plug on each ignition coil and spark plug wire. Ground spark plugs against cylinder block.
    3. CAUTION: To prevent gasoline from being injected, DO NOT crank engine for longer than 5 seconds when checking for spark.
  3. Crank engine and check for spark. If spark exists at spark plug on ignition coil, but not at spark plug on spark plug wire, go to next step. If spark does not exist at any spark plug, check ignition coil and ignitor electrical connections. Ignitor is located in engine compartment, on top of driver's side strut tower. If electrical connections are okay, go to step  5. If electrical connections are defective, repair as necessary and recheck for spark.
  4. Using ohmmeter, check resistance of spark plug wire. Replace spark plug wire if resistance exceeds 25,000 ohms per wire.
  5. Turn ignition on. Using voltmeter, check for battery voltage at positive terminal on ignitor and ignition coil. See appropriate wiring diagram in WIRING DIAGRAMS article. If battery voltage exists, go to next step. If battery voltage does not exist, check wiring between ignition switch, ignition coil and ignitor. See appropriate wiring diagram in WIRING DIAGRAMS article.
  6. Check ignition coil resistance. See IGNITION COIL RESISTANCE . If ignition coil resistance is within specification, go to next step. If ignition coil resistance is not within specification, replace ignition coil.
  7. Check resistance of camshaft position sensor. See CAMSHAFT POSITION SENSOR RESISTANCE . If camshaft position sensor resistance is within specification, go to next step. If camshaft position sensor resistance is not within specification, replace camshaft position sensor. See ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
  8. Check resistance of crankshaft position sensor. See CRANKSHAFT POSITION SENSOR RESISTANCE . If crankshaft position sensor resistance is within specification, go to next step. If crankshaft position sensor resistance is not within specification, replace crankshaft position sensor. See IGNITION SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article.
  9. Check ignition IGT signal from Engine Control Module (ECM) to ignitor. If ignition IGT signal from ECM is defective, Diagnostic Trouble Code (DTC) P1300 should set in the ECM memory to indicate an ignitor circuit malfunction. See SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article for retrieving of DTCs.
  10. If ignition IGT signal is okay, substitute another ignitor and recheck system operation. If ignition IGT signal is defective, check wiring between ECM and ignitor. On GS300, ECM is located at driver's side front corner of engine compartment. On SC300, ECM is located under passenger's side front carpet below instrument panel. On all models, if wiring is defective, repair wiring as necessary and recheck system operation. If wiring is okay, substitute another ECM and recheck system operation. Reinstall components. Install and tighten spark plugs to 13 ft. lbs. (18 N.m).
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