How To Test The Igniter -Step By Step (1995-1996 1.5L Toyota Tercel)

TEST 5: Testing The Ignition Coil Control Signals

You've reached this last test because you have tested and confirmed that:

• All four cylinders are not getting spark (TEST 1).
• The igniter is getting battery power and Ground (TEST 2 and 3).
• The igniter is getting both the IGT1 and IGT2 signals (TEST 4).

Since the igniter is receiving all these, it should create two separate ignition coil control signals (IGC1 and IGC2).

So in this last test step, we're gonna' use an LED light to see if the igniter (ignition module) is creating the IGC1 and IGC2 control signals that the ignition coils need to start sparking.

We'll check for these signals directly at the ignition coil connectors

NOTE: The IGC1 signal is the one that activates the 1/4 ignition coil and the IGC2 signal is the one that activates the 2/3 ignition coil.

IMPORTANT: The igniter must remain connected to its electrical connector for this test to function.

These are the test steps:

1. 1

   Disconnect 1/4 (or 2/3) ignition coil from its electrical connector.

2. 2

   Connect the red LED wire to terminal #1 of the ignition coil harness connector (see illustration above). The wire that connects to the #1 terminal is a black with orange stripe (BLK/ORG) wire.
   
   CAUTION: You'll connect the LED wire to the female terminal of the connector. Do not insert a large diameter test lead into the female terminal of the ignition coil connector or you'll damage the female terminal!

3. 3

   Connect the black LED wire to the #2 terminal of the ignition coil harness connector (see illustration above). The wire connecting to the #2 terminal should be a red (RED) wire.

4. 4

   After the LED light is set up, have your helper crank the engine as you observe the LED light.

5. 5

   The LED light should flash ON and OFF in steady pulses as the engine is cranking if the IGC signal is present (for this ignition coil being tested).

6. 6

   Repeat steps 1 thru' 5 on the 2/3 ignition coil harness connector to test for the IGC2 signal.
   
   NOTE: On 2/3 ignition coil connector, terminal #2 has a red with white stripe (RED/WHT) wire and terminal #1 is the same color (BLK/ORG).

Let's take a look at what your test results mean:

CASE 1: The LED light flashed on both ignition coil connectors. This is the correct and expected test result and tells you that the igniter is creating and sending the IGC1 and IGC2 control signals to the ignition coils.

This test result tells you that the igniter (ignition control module) is functioning correctly and that the 'no spark, no start' condition is due to another cause.

CASE 2: The LED light DID NOT flash on both ignition coil connectors. This tells you that the igniter is not activating the ignition coils.

You can now conclude that the igniter is defective only if you have tested and confirmed that:

• All four cylinders are not getting spark (TEST 1).
• The igniter is getting battery power and Ground (TEST 2 and 3).
• The igniter is getting both the IGT1 and IGT2 signals (TEST 4).
• The igniter is not creating/sending the IGC1 and IGC2 signals to the ignition coils (TEST 5).