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Spark Test

NOTE: LS400 and SC400 have 2 distributors and 2 ignition coils. Distributors are located at front end of each cylinder head, under cover.
  1. Disconnect coil wire from distributor(s). Using insulated pliers, hold end of coil wire 1/2" from ground. Crank engine for 1-2 seconds. If spark is present, see appropriate DIAGNOSIS BY SYMPTOM in TROUBLE SHOOTING - NO CODES article.
  2. If spark is not present, turn ignition off. Check ignition coil, ignitor and distributor connectors. Repair as necessary.
  3. If connectors are okay, check resistance of high tension cables. Maximum resistance is 25,000 ohms per cable. Replace as necessary. If resistance is within specification, go to next step.
  4. Turn ignition on. Disconnect ignition coil connector. Check voltage at ignition coil positive wire terminal (White/Red wire terminal on ES300; Black/Orange wire terminal on all others). If battery voltage is not present, check wiring between ignition switch and ignition coil.
  5. If battery voltage is present, turn ignition off. Measure ignition coil resistance (cold). See IGNITION COIL RESISTANCE  table. If resistance is not within specification, replace ignition coil.
  6. If resistance is within specification, check resistance across terminals of appropriate distributor sensor (distributor pick-up coil, camshaft sensors, crankshaft sensor, etc.). See Fig 1-4. See DISTRIBUTOR SENSOR RESISTANCE  table.
    NOTE: Crankshaft sensor may also be called engine speed sensor.
  7. If resistance is not within specification, replace appropriate component (distributor housing, camshaft sensor or crankshaft sensor). If resistance is within specification, go to next step (ES300, GS300 and SC300), or go to step 9) (LS400 or SC400).
  8. Measure air gap of pick-up coils G1, G2 and NE. See Fig 4. See DISTRIBUTOR PICK-UP COIL AIR GAP  table. If air gap is within specification, go to next step. If air gap is not within specification, replace distributor.
  9. Check ignition signal from ECM to ignitor. See procedure for Code 14 (and Code 15 on LS400 and SC400) in SELF-DIAGNOSTICS article. If ignition signal and its circuit are okay, replace ignitor.
IGNITION COIL RESISTANCE

Application Primary Secondary
ES300 .30-.60 9000-15,000
GS300
Cold .21-.33 6400-11,100
Hot .27-.39 8200-13,000
LS400
Cold .36-.55 9,000-15,400
Hot .45-.65 11,400-18,100
SC300 .20-.30 6000-11,000
SC400 .40-.50 10,000-14,000
DISTRIBUTOR SENSOR RESISTANCE

Application Ohms
ES300 (Pick-Up Coils)
Between Terminals G1 & "G" 125-190
Between Terminals G2 & "G" 125-190
Between Terminals NE & "G" 155-240
GS300 (Pick-Up Coils)
Cold
Between Terminals G1 & "G" 125-200
Between Terminals G2 & "G" 125-200
Between Terminals NE & "G" 155-200
Hot
Between Terminals G1 & "G" 160-235
Between Terminals G2 & "G" 160-235
Between Terminals NE & "G" 190-290
SC300 (Pick-Up Coils)
Between Terminals G1 & "G" 125-190
Between Terminals G2 & "G" 125-190
Between Terminals NE & "G" 155-240
LS400 (Camshaft Sensors & Crankshaft Sensor)
Cold 835-1400
Hot 1060-1645
SC400 (Camshaft Sensors & Crankshaft Sensor) 835-1350
DISTRIBUTOR PICK-UP COIL AIR GAP (1)

Application In. (mm)
ES300 & GS300 .008-.020 (.20-.50)
SC300 .008-.016 (.20-.40)
(1) Not adjustable. If gap is incorrect, replace distributor housing.
Fig 1: Checking Pick-Up Coil Resistance (ES300, GS300 & SC300)
G93A78188Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 2: Checking Right Camshaft Sensor Resistance (Left Is Similar)
G93B78189Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 3: Checking Crankshaft (Engine Speed) Sensor Resistance
G90E18881Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 4: Measuring Pick-Up Coil Air Gaps (ES300, GS300 & SC300)
G93E78190Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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