Toyota Supra 1990 Manual page 349

Voltmeter
o
Ohmmeter
Ohmmeter
IGNITION SYSTEM - On-Vehicle Inspection (7M-GTE)
IG-15
IG0673
INSPECTION OF IGNITER
1. CHECK POWER SOURCE LINE VOLTAGE
(a) Disconnect the connector 6-P.
2.
(b) Turn the ignition switch ON.
(c) Using a voltmeter, connect the positive
(+)
probe to
terminal 3 of the harness side and negative (-) probe
to body ground.
Voltage: Approx. 12 V
(d) Connect the connector 6-P.
CHECK POWER TRANSISTOR IN IGNITER
(a) Disconnect the connector 4-P.
(b) Disconnect each ignition coil from its connector.
(c) Turn the ignition switch ON.
(d) Using an ohmmeter, connect terminal 2 of ignition coil
C and body ground.
(e) Using a 3V dry cell battery, apply voltage to terminal
2 of connector 4-P.
As voltage is applied, check that there is momentary
continuity.
(f) Using an ohmmeter, connect terminal 2 of ignition coil
A and body ground.
(g) Using a 3V dry cell battery, apply voltage to terminal
4 of the 4-P connector.
(h) With terminal 4 connected apply voltage to terminal
2 of connector 4-P. As you apply voltage, check that
there is momentary continuity.
(i) Using an ohmmeter, connect terminal 2 of ignition coil
B and body ground.
(i)
Using a 3V dry cell battery, apply voltage to terminal
3 of the 4-P connector.
(k) With terminal 3 connected apply voltage to terminal
2 of connector 4-P. As you apply voltage, check that
there is momentary continuity.