TEST 4: Checking For The Ignition Coil's Activation Signal
If you've reached this point, you've confirmed that either the 1/4 ignition coil or the 2/3 ignition coil is not creating and delivering spark to its two cylinders.
To be more specific, in TEST 1, you have confirmed that the ignition coil's spark plug wire and spark plug boot are not firing spark.
In this test section, we're going to ensure that this specific ignition coil (that isn't sparking from both its ends) is receiving an activation signal.
To check for the ignition coil's activation signal, we're gonna use an LED light. If you don't have one and need to buy one, you can do it here: The LED Light Test Tool And How To Make One (at: easyautodiagnostics.com).
Let's get testing:
- 1
Disconnect the ignition coil from its electrical connector.
- 2
Connect the red LED wire to terminal 1 of the ignition coil harness connector (see illustration above).
The wire that connects to terminal 1 is a black with white stripe (BLK/WHT) wire or 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
Connect the black LED wire to terminal 2 of the ignition coil harness connector (see photo above).
- 4
After the LED light is set up, have your helper crank the engine as you observe the LED light.
- 5
The LED light should flash ON and OFF as the engine cranks.
Let's take a look at what your test results mean:
CASE 1: The LED light flashed ON and OFF. This is the correct and expected test result and tells you that the ignition coil is receiving its activation signal.
You can correctly conclude that the ignition coil is bad if you have:
- Confirmed that the ignition coil's spark plug wire and spark plug boot DO NOT spark (TEST 1).
- Confirmed that the ignition coil is receiving an activation signal (this test section).
CASE 2: The LED light DID NOT flash ON and OFF. This tells you that the ignition coil is not receiving an activation signal.
The most likely cause of this missing ignition coil activation signal is a bad igniter (ignition control module).
The following tutorial will help you test the igniter:
- How To Test The Igniter -Step By Step (1995-1996 1.5L Toyota Tercel).
- How To Test The Igniter (1997-1998 1.5L Toyota Tercel).
TEST 5: Checking The Ignition Coils' Activation Signals
It's rare for both ignition coils to fail at the same time. But when it does happen, it's because they are not receiving an activation signal from the ignition control module (igniter).
Since your test results from TEST 1 confirm that all four cylinders are not getting spark, we're gonna check the activation signal of both ignition coils.
We'll use an LED light to test the ignition coil's activation signal. If you don't have an LED light and need to buy one, you can do it here: The LED Light Test Tool And How To Make One (at: easyautodiagnostics.com).
Let's get testing:
- 1
Disconnect the 1/4 ignition coil from its electrical connector.
- 2
Connect the red LED wire to terminal 1 of the ignition coil harness connector (see illustration above).
The wire that connects to terminal 1 is a black with white stripe (BLK/WHT) wire or 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
Connect the black LED wire to terminal 2 of the ignition coil harness connector (see photo above).
- 4
After the LED light is set up, have your helper crank the engine as you observe the LED light.
- 5
The LED light should flash ON and OFF as the engine cranks.
- 6
Repeat test steps 1 thru 5 on the 2/3 ignition coil.
Let's take a look at what your test results mean:
CASE 1: The LED light flashed ON and OFF on both ignition coil connectors. This is the correct and expected test result and tells you that both ignition coils are receiving an activation signal.
You can correctly conclude that the ignition coils are bad if you have:
- Confirmed that both ignition coils' spark plug wires and spark plug boots DO NOT spark (TEST 1).
- Confirmed that both ignition coils are receiving an activation signal (this test section).
CASE 2: The LED light DID NOT flash ON and OFF on both ignition coil connectors. This tells you that the ignition coils are not receiving an activation signal.
The most likely cause of these missing ignition coil activation signals is a bad igniter (ignition control module) or a bad crankshaft position (CKP) sensor.
The following tutorial will help you test the igniter and the crankshaft position sensor (begin with the igniter test):
- How To Test The Igniter -Step By Step (1995-1996 1.5L Toyota Tercel).
- How To Test The Igniter (1997-1998 1.5L Toyota Tercel).
- How To Test The CKP Sensor (1995-1998 1.5L Toyota Tercel).
More 1.5L Toyota Tercel Tutorials
You can find a complete list of 1.5L Toyota Tercel tutorials and wiring diagrams in this index:
Here's a sample of the tutorials you'll find in the index:
- How To Test The Igniter -Step By Step (1995-1996 1.5L Toyota Tercel).
- How To Test Engine Compression (1.5L Toyota Tercel).
- How To Test The Fuel Injectors (1995-1996 1.5L Toyota Tercel).
- How To Test For A Blown Head Gasket (1.5L Toyota Tercel).
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