How To Test The Igniter (1991-1994 1.5L Toyota Tercel)

The igniter (ignition control module) on the 1991-1994 1.5L Toyota Tercel can be easily tested to find out if it has failed and causing the engine to not start.

In this tutorial, I'll walk you through a simple, step-by-step process to help you diagnose whether the igniter is functioning properly or not, and you don't have to remove it from the car to test it.

APPLIES TO: This tutorial applies to the following vehicles:

• 1.5L Toyota Tercel: 1991, 1992, 1993, 1994.

IMPORTANT: Before testing the igniter, check the ignition coil for spark first.

If spark is present, it confirms the igniter is working properly and there's no need to proceed with this tutorial. If you haven't already tested the ignition coil, do so first:

• Engine No-Start Ignition System Tests (1991-1994 1.5L Toyota Tercel).

Ignition System Wiring Diagrams:

• Ignition System Wiring Diagram (1991-1994 1.5L Toyota Tercel).

Distributor Pickup Coil Tests:

• How To Test The Distributor Pickup Coil (1991-1994 1.5L Toyota Tercel).

Symptoms Of A Bad Igniter

The igniter (also known as the ignition control module) is one of the key ignition system components that gets the engine to start and stay running. It works with the fuel injection computer to:

• Activate the ignition coil to fire spark.
• Control timing by adjusting when and how long the ignition coil produces a spark.
• Signal back to the fuel injection computer the engine is cranking or running, allowing it to activate the fuel pump and fuel injectors.

When the igniter fails, the ignition coil doesn't get activated to produce and deliver spark to the spark plugs. Additionally, the fuel pump and fuel injectors won't activate, causing the engine to fail to start due to a lack of both spark and fuel delivery.

Igniter Circuit Descriptions

The igniter (ignition control module) has 5 wires coming out of its connector. Each one has a specific job to do and here's a brief description of each:

Pin	Wire Color	Description
1	Light green with yellow stripe (LT GRN/YEL)	IGF -Ignition coil firing feedback
2	Light green (LT GRN)	IGT -Igniter control signal
3	Black with red stripe (BLK/RED)	+B -Battery power
4	Black (BLK)	IG- -Tachometer signal
5	Black with blue stripe (BLK/WHT)	+B2 -Ignition coil control signal

NOTE: The igniter harness connector has female metal terminals. You'll need to use a back probe or a wiring piercing probe to test the signals in the wires.

Basic Operation Theory Of The Igniter

When you turn the key and crank the engine on your 1992-1993 1.5L Toyota Tercel, quite a few things happen for the ignition system to create and distribute spark to all four cylinders and get the engine started and keep it running.

Here's what happens:

1. The igniter receives power from the ignition switch (10 to 12 Volts DC).
   • This power comes through the black with red stripe (BLK/RED) wire on the igniter's 5-wire connector, which also supplies power to the ignition coil.
2. As you crank the engine, the pickup coil inside the distributor generates its NE signal. This signal is sent directly to the fuel injection computer.
3. After receiving the NE signal, the ECM sends an IGT (Ignition Timing) signal to the igniter.
   • The IGT signal commands the igniter to trigger the ignition coil.
   • The IGT signal is fed by the light green (LT GRN) wire to terminal 2 of the igniter.
4. When the igniter gets the IGT signal, it sends an activation signal, known as +B2, to the ignition coil.
   • The +B2 exits terminal 5 of the igniter and is delivered to the ignition coil by the black with blue stripe (BLK/BLU) wire.
   • The +B2 signal activates the ignition coil to fire spark.
5. Once the ignition coil fires, the igniter sends back an IGF (Ignition Feedback) signal to the fuel injection computer.
   • The IGF confirms the ignition coil has been activated, signaling the fuel injection computer to enable the fuel pump and fuel injectors.

With this info under our belts, let's begin our tests.

Where To Buy The Igniter

The following links will help you shop for the igniter made by Delphi (a well-known, but pricey automotive brand) and cheaper priced X-brand:

NOTE: Not sure if the igniter fits your particular Tercel? Don't worry. Once you get to the site, they ask you the specifics of your vehicle. If it doesn't fit, they'll find you the right one.

TEST 1: Making Sure The Igniter Is Getting Power

IMPORTANT: If the ignition coil is creating and delivering spark to all four cylinders, the igniter is functioning correctly. If you haven't already tested the ignition coil for spark, please do so before testing the igniter:

• Engine No-Start Ignition System Tests (1992-1993 1.5L Toyota Tercel).

To get our igniter diagnostic started, we'll first begin by making sure it's getting power (10 to 12 Volts DC).

The wire that delivers this voltage to the igniter is the black with red stripe (BLK/RED) wire which connects to the female terminal labeled with the number 3 (see photo above).

Once we've confirmed that the igniter is receiving power, we'll move on to TEST 2.

These are the test steps:

1. 1

   Disconnect the igniter from its 5-wire electrical connector.

2. 2

   Connect the black multimeter test lead to the battery negative (-) terminal.

3. 3

   Have your helper turn the key to the ON position.

4. 4

   Place your multimeter in Volts DC mode.

5. 5

   Gently probe female terminal number 3 (of the 5-wire connector) with the red multimeter test lead.
   
   NOTE: Verify that female terminal number 3 of the igniter's 5-wire connector corresponds to the BLK/RED wire.

6. 6

   Your multimeter should read 10 to 12 Volts DC.

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

CASE 1: 10 to 12 Volts are present in terminal 3. This is the correct and expected test result. The next step is to make sure the igniter is getting Ground. For this step, go to: TEST 2: Making Sure The Igniter Is Getting Ground.

CASE 2: 10 to 12 Volts ARE NOT present in terminal 3. This tells you that the igniter is not working due to a lack of battery power.

Your next step is to find out why this battery power is missing and restore it. Once battery power is restored, the igniter should function again.