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IGNITION SYSTEM IGNITION SYSTEM IGNITION SYSTEM
IG1 The ECM monitors the engine condition by signals from each sensor, calculates the ignition
timing and sends an ignition signal to the igniter. High voltage from the ignition is distributed to
each spark plug in the appropriate order to generate a spark between the electrodes, which
ignites the airfuel mixture.
IGNITER
The igniter temporarily interrupts the primary current with the ignition signal (lGT signal) from the
ECM and generates sparks at the spark plug. Also, as a failsafe measure, when ignition occurs
an ignition confirmation signal (IGF signal) is sent to the ECM.
IGNITION COIL
The ignition coil uses a closed core coil with the primary coil wrapped around the core and the
secondary coil wrapped around the primary coil. This allows the generation of a high voltage
sufficient to cause a spark to jump across the spark plug gap.
DISTRIBUTOR
This correctly distributes high voltage to the spark plug of each cylinder in the specified ignition
order.
PICKUP COILS
The NE coil detects the crankshaft angle, and the G 1 and G2 coils detect the camshaft position.
DESCRIPTION
The engine control module (ECM) is programmed with data for optimum ignition timing unndr all
operating conditions. Using data provided by sensors which monitor various engine functions
(rpm, intake air volume, engine temperature, etc.), the ECM triggers the spark at precisely the
right instant.
(5SFE California) IGNITION SYSTEM
(5SFE California)
IG2 3. As some tachometers are not compatible with this
ignition system, we recommend that you confirm
the compatibility of yours before use.
4. Never allow the tachometer terminals to touch
ground as it could result in damage to the igniter
and/or ignition coil.
Do not disconnect the battery while the engine is
running.
6. Check that the igniter is properly grounded to the
body.
PRECAUTION
1. Do not leave the ignition switch on for more than 10
minutes if the engine does not start.
2. With a tachometer connected to the system, con
nect the tester probe of the tachometer to terminal
IG() of the data link connector 1. IGNITION SYSTEM
(5SFE California)
IG3 OPERATION
To maintain the most appropriate ignition timing, the ECM sends a control signal so that the
igniter sends current to the ignition coil and the spark plugs produce a spark.
SYSTEM CIRCUIT IGNITION SYSTEM
(5SFE California)
IG4 PREPARATION
SST (SPECIAL SERVICE TOOLS)
RECOMMENDED TOOLS
0908200050 TOYOTA Electrical Tester Set
0984318020 Diagnosis Check Wire
0920000010 Engine Adjust Kit
0924000020 Wire Gauge Set
EQUIPMENT
Spark plug cleaner
Timing light
Ignition timing
Tachometer
Air gap IGNITION SYSTEM
(5SFE California)
IG5 ONVEHICLE INSPECTION
SPARK TEST

CHECK THAT SPARK OCCURS
(a) Disconnect the hightension cord (from the ignition
coil) from the distributor cap.
(b) Hold the end approx. 12.5 mm (0.50 in.) from the body
ground.
(c) See if spark occurs while engine is being cranked.
HINT: To prevent gasoline from being injected from
injectors during this test, crank the engine for no more
than 12 seconds at time.
If the spark does not occur, perform the test as fol
lows:
CHECK RESISTANCE OF SIGNAL
GENERATOR (PICKUP COIL)
See page (
IG12
)
Resistance: Cold HotG1 and G125200
W
160235
W
G 2 and G125200
W
160235
W
N E and G155250
W
190290
W
CHECK RESISTANCE OF IGNITION COIL
See page
IG10
)
Resistance: Cold Hot
Primary 0.360.55 0 0.450.65
W
Secondary 9.015.4 k
W
11.418.1 k
W
CHECK POWER SUPPLY TO IGNITION
COIL AND IGNITER
1. Turn ignition switch to ON.
2. Check that there is battery voltage at
ignition coil positive (+) terminal.
CHECK RESISTANCE OF HIGHTENSION
CORD (See Page
IG7
)
Maximum resistance: 25 k
W
per cord
CHECK AIR GAP OF DISTRIBUTOR
(See page
IG11
)
Air gap: 0.20.5 mm (0.0080.020 in.)
CHECK CONNECTION OF IGNITION COIL,
IGNITER AND DISTRIBUTOR CONNECTOR
CHECK IGT SIGNAL FROM ECM
(See page
EG344
)
Check wiring between ECM, distributor
and igniter, only then try another ECM.
Check wiring between ignition switch
to ignition coil and igniter.
Replace the distributor housing
assembly.
Replace the distributor housing
assembly.
TRY ANOTHER IGNITER
Replace the ignition coil.
Replace the cord
(s).
Connect securely.
SPARK TEST
BAD
BAD
BAD
BAD
BAD
BAD
BAD IGNITION SYSTEM
(5SFE California)
IG6 4. INSPECT HIGHTENSION CORD RESISTANCE
Using an ohmmeter, measure the resistance.
Maximum resistance:
25 k
W
per cord .
If the resistance is greater than maximum, check the
terminals. If necessary, replace the hightension
cord.
1. DISCONNECT HIGHTENSION CORDS FROM
SPARK PLUGS
Disconnect the hightension cords at the rubber
boot. Do not pull on the hightension cords.
NOTICE: Pulling on or bending the cords may damage the
conductor inside.
6. RECONNECT HIGHTENSION CORDS TO
DISTRIBUTOR CAP
6. RECONNECT HIGHTENSION CORD TO IGNITION
COIL
7. RECONNECT HIGHTENSION CORDS TO SPARK
PLUGS
2. DISCONNECT HIGHTENSION CORD FROM
IGNITION COIL
3. DISCONNECT HIGHTENSION CORDS FROM
DISTRIBUTOR CAP
HIGHTENSION CORDS INSPECTION IGNITION SYSTEM
(5SFE California)
IG7 2. INSPECT ELECTRODE
Using a megger (insulation resistance meter), measure
the insulation resistance.
Standard correct insulation resistance:
10 M
W
or more
If the resistance is less than specified, proceed to step
4.
HINT: If a megger is not available, the following simple
method of inspection provides fairly accurate results.
SPARK PLUGS INSPECTION
NOTICE: Never use a wire brush for cleaning. Never attempt to adjust the electrode gap on a used
spark plug. Spark plugs should be replaced every 100.000 km
(60.000 miles).
Simple Method:
(a) Quickly race the engine to 4,000 rpm 5 times.
(b) Remove the spark plug. (See step 4)
(c) Visually check the spark plug.
If the electrode is dry ... OK
If the electrode is wet ... Proceed to step 5
(d) Reinstall the spark plug. (See step 8)
1. DISCONNECT HIGHTENSION CORDS FROM
SPARK PLUGS
Disconnect the hightension cords at the rubber
boot. Do not pull on the cords.
NOTICE: Pulling on or bending the cords may damage the
conductor inside.
3. REMOVE SPARK PLUGS
Using a 16 mm plug wrench, remove the 4 spark
plugs. IGNITION SYSTEM
(5SFE California)
IG8 5. INSPECT ELECTRODE GAP
Maximum electrode gap for used spark plug:
1.3 mm (0.051 In.)
If the gap is greater than maximum, replace the spark
plug.
Correct electrode gap for new spark plug:
1.1 m m (0.043 in.)
NOTICE: if adjusting the gap of a new spark plug, bend
only the base of the ground electrode. Do not touch the
tip. Never attempt to adjust the gap on the used plug.
6. CLEAN SPARK PLUGS
If the electrode has traces of wet carbon, allow it to
dry and then clean with a spark plug cleaner.
Air pressure:
Below 588 kPa (6 kgf/cm2, 85 psi)
Duration:
20 seconds or less
HINT: If there are traces of oil, remove it with gasoline
before using the spark plug cleaner.
4. VISUALLY INSPECT SPARK PLUGS
Check the spark plug for thread damage and insulator
damage.
If abnormal, replace the spark plug.
Recommended spark plug:
PK20R11 for ND
BKR6EP11 for NGK
7. REINSTALL SPARK PLUGS
Using a 16 mm plug wrench, install the 4 spark plugs.
Torque: 18 Nm (180 k9fcm. 13 ftlbf)
8. RECONNECT HIGHTENSION CORDS T4 SPARK
PLUGS IGNITION SYSTEM
(5SFE California)
IG9 3. INSPECT PRIMARY COIL RESISTANCE
Using an ohmmeter, measure the resistance between
the positive (+) and negative () terminals.
Primary coil resistance (Cold):
0.360.55
W
Primary coil resistance (Hot):
0.45O.65
W
If the resistance is not as specified, replace the igni
tion coil.
4. INSPECT SECONDARY COIL RESISTANCE
Using an ohmmeter, measure the resistance between
the positive (+) and hightension terminals.
Secondary coil resistance (Cold):
9.015.4 k
W
Secondary coil resistance (Hot):
11.418.1 k
W
If the resistance is not as specified, replace the igni
tion coil.
IGNITION COIL INSPECTION
NOTICE: Cold and Hot in the following sentences ex
press the temperature of the coils themselves. Cold is
from10
_
C (14
_
F) to 50
_
C (122
_
F) and Hot is from
60
_
C
(122 F) to 100
_
C (212
_
F).
1. DISCONNECT IGNITION COIL CONNECTOR
2. DISCONNECT HIGHTENSION CORD FROM
IGNITION COIL
6. RECONNECT HIGHTENSION CORD TO IGNITION
COIL
6. RECONNECT IGNITION COIL CONNECTOR IGNITION SYSTEM
(5SFE California)
IG10 4. INSPECT AIR GAP
Using SST (G1 and G2 pickups) and a feeler gauge (NE
pickup), measure the air gap between the signal rotor
and pickup coil projection.
SST 0924000020 for G 1 and G2 pickups
Air gap:
0.20.5 mm (0.0080.020 in.)
If the air gap is not as specified, replace the distributor
housing assembly.
DISTRIBUTOR INSPECTION
NOTICE: Cold and Hot in the following sentences ex
press the temperature of the coils themselves. Cold is
from10
_
C (14
_
F) to 50
_
C (122
_
F) and Hot is from
50
_
C (122
_
F) to 100
_
C (212
_
F).
1. REMOVE DISTRIBUTOR CAP
Remov