Service manual

15
8/14/02
15
CAUTION:
Do not remove the valve from the housing when
performing this test.
3. Disconnect the engine coolant sensor.
4. Reconnect the idle air control valve to the har-
ness.
5. Press the engine start button quickly without turn-
ing over the engine. The valve should extend fully.
6. Reconnect the coolant sensor and observe move-
ment of the valve arm; the valve should retract
slightly.
If the valve does not move, replace it with a new
one.
Static Test - Resistance
1. Remove the valve mounting screws and remove
the valve from the bypass housing.
2. Inspect the housing pintel seat and valve pintel
end for damage.
3. Measure resistance across sensor terminals (A)
to (D). The resistance should be 53
± 10% Ohms.
4. Measure resistance across sensor terminals (C)
to (B). The resistance should be 53
± 10% Ohms.
IGNITION COIL
The ignition coil is a “pencil-type” coil located on top
of the spark plug within the cylinder head.
The ECU controls when the coil is switched on or
off. The coil is switched on to allow sufficient time for
the coil to charge to a level where a spark can be
produced at the spark plug. The coil switches off at
ignition, which is timed for good engine performance.
Inspection Points
1. Check the coil body for damage (e.g., burning,
cracks, discoloration (excessive heat).
2. Check the coil terminal pins. Make sure they are
in good condition.
3. Check the condition of the tip insulator. Make sure
it is not cracked, burned, melted, dried out.
4. Make sure the spring is installed with the larger
end facing the coil.
Dynamic Test - Spark Occurrence
1. Disconnect the ignition coil from the harness
connector.
2. Remove the retaining clip bolt and coil retainer.
3. Lift the ignition coil out of the cylinder head.
4. Reconnect the harness.
5. Insert a commercially available spark tester into
the end of the coil. Connect the ground lead of the
indicator to the cylinder head.
6. Turn the ignition switch on and press the engine
start button. If spark is indicated, the coil is OK.
Static Test - Primary Resistance
1. Measure the resistance between the coil terminal
pins.
EMS POWER RELAY
The EMS power relay supplies the ECU with power
when the vehicle start button is pressed and will
remain locked when the engine is running. The
relay will hold for up to 2 minutes without the engine
running or turning over, then it will drop power to
ECU.
WARNIN
G
An energized ignition coil generates a
high voltage spark capable of jumping to a
ground point. The following procedure will
create a spark that can ignite any available
fuels. You can be seriously injured or killed
in a resulting fire or explosion.
Make sure the work area and vehicle are
free of any gasoline or flammable liquids
(flooded engine, fuel tank, fuel hoses, sol-
vents).