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

The pickup coil in your Tercel's distributor acts as the crankshaft position sensor. The signal it sends to the fuel injection computer lets it know whether the engine is cranking or running so that it can activate the ignition and fuel systems.

In this tutorial, I'll show you how to test the pickup coil to find out if it's bad and causing a no-start issue, or if it's functioning correctly and not the source of your Tercel's starting problem.

APPLIES TO: This tutorial applies to the following vehicles:

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

Ignition System Tests:

• Engine No-Start Ignition System Tests (1991-1994 1.5L Toyota Tercel).
• How To Test The Igniter (1991-1994 1.5L Toyota Tercel).

Ignition System Wiring Diagram:

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

What Does The Distributor Pickup Coil Do?

Here are some of the pickup coil key details that'll help us diagnose it in the tests to follow:

• Magnetic Sensor: The pickup coil consists of a magnetic sensor and a reluctor wheel (a toothed wheel attached to the distributor shaft).
• Signal Creation: As the engine cranks (or runs), the reluctor wheel spins with the distributor shaft, its teeth pass by the magnetic sensor, generating an AC voltage signal.
  • This signal serves as a timing reference for the fuel injection computer, letting it know when each cylinder reaches top dead center (TDC) on the compression stroke.
• Ignition Spark and Timing Control: The fuel injection computer uses this AC signal to determine when to trigger the ignition coil via the igniter (ignition control module).
  • The ignition coil then produces a high-voltage spark, which is sent to the correct spark plug via the distributor cap and rotor.

Symptoms Of A Bad Pickup Coil

A malfunctioning or failed pickup coil can cause several issues that affect engine performance or prevent it from starting altogether. The two most common symptoms are:

1. Engine no-start problem:
   • The igniter won't receive the correct signal.
   • The ignition coil won't fire spark.
   • The fuel injectors aren't enabled.
   • The fuel pump isn't enabled.
2. Engine runs rough and stalls:
   • The engine may run erratically, misfire, or stall unexpectedly while driving.

Distributor Connector Circuit Descriptions

The distributor on your 1.5L Toyota Tercel has two connectors, and each connector has two wires:

• Ignition coil connector: This connector supplies 12 Volts and the ignition coil activation signal to the ignition coil.
• Pickup coil connector: The other connector is for the pickup coil and its wires transmit its signal to the fuel injection computer.

To identify the correct connector, I usually remove the distributor cap and trace the wiring from each connector to see where it leads:

• If the wires go to the pickup coil (near the reluctor wheel), that's the pickup coil connector.
• If they go to the ignition coil, that's the ignition coil connector.

Taking this extra step avoids any mix-ups and ensures I'm testing the correct component.

Where To Buy The Distributor Pickup Coil

The pickup coil isn't sold separately from the distributor, so if your test results indicate it's bad, you'll need to buy the entire distributor.

NOTE: Not sure if the distributor or spark plug wires fit your particular Tercel? Don't worry. Once you get to the site, they'll ask you for the specifics of your vehicle. If they don't fit, they'll find you the right ones.

TEST 1: Checking The Pickup Coil's Resistance With A Multimeter

When the distributor pickup coil fails, it's usually due to an internal short-circuit or an open-circuit problem.

We can easily test for these issues using a multimeter set to Ohms (Ω) mode, and that's exactly what we'll do in this section.

If the pickup coil is functioning correctly (no internal shorts or open-circuits), the multimeter should display a resistance value between 370 and 530 Ohms (with the engine cold).

Let's get started:

1. 1

   Disconnect the pickup coil from its engine wiring harness connector.

2. 2

   Set your multimeter to Ohms mode.

3. 3

   Measure the resistance across the two male spade terminals of the pickup coil connector.

4. 4

   The multimeter should read 370-530 Ohms.

Let's interpret your test result:

CASE 1: The pickup coil's resistance is within specification. This test result confirms that the pickup coil is functioning correctly.

Although not necessary, you can further confirm the pickup coil is good by performing TEST 2. Go to: TEST 2: Testing The Pickup Coil's Output With A Multimeter.

CASE 2: The pickup coil's resistance IS NOT within specification. This test result confirms that the pickup coil is bad and needs replacement.

Although not necessary, you can further confirm the pickup coil is bad by performing TEST 2. Go to: TEST 2: Testing The Pickup Coil's Output With A Multimeter.

TEST 2: Testing The Pickup Coil's Output With A Multimeter

When the engine is cranking, the pickup coil generates an AC voltage. This can be easily tested using a multimeter set to Volts AC mode.

• If the pickup coil is functioning correctly, your multimeter should show an AC voltage reading between 0.4 and 1.2 Volts AC while the engine is cranking.
• If the pickup coil is faulty, the multimeter will display 0 Volts AC during cranking.

NOTE: The AC voltage output depends on the engine's cranking speed, which in turn relies on a fully charged battery. To get the most accurate test result, make sure the battery is fully charged before performing this test. If the battery is low, charge her up fully first.

OK, let's get going:

1. 1

   Disconnect the pickup coil connector from its engine wiring harness connector.

2. 2

   Place your multimeter in Volts AC mode.

3. 3

   With your multimeter test leads, probe the male spade terminals of the pickup coil connector's male spade terminals.
   
   NOTE: You're probing the male spade terminals of the pickup coil's connector itself and not the female terminals of the engine wiring harness connector.

4. 4

   Have a helper crank the engine as you observe the multimeter.
   
   CAUTION: Be careful and stay alert as the engine is cranking.

5. 5

   The multimeter should report an AC voltage that will oscillate somewhere around 0.4 to 1.2 Volts AC.

Let's interpret your test result:

CASE 1: The multimeter reported the indicated AC voltage. This test result confirms that the pickup coil is functioning correctly.

CASE 2: The multimeter reported 0 AC voltage. This test result confirms that the pickup coil is bad and needs replacement.

More 1.5L Toyota Tercel Tutorials

You can find a complete list of diagnostic tutorials for the 1.5L Toyota Tercel in this index:

• 1.5L Toyota Tercel Index Of Articles.

Here's a sample of the tutorials you'll find in the index:

• How To Test The Starter Motor (1993-1998 1.5L Toyota Tercel).
• How To Test For A Blown Head Gasket (1991-1998 1.5L Toyota Tercel).
• How To Test Engine Compression (1991-1998 1.5L Toyota Tercel).
• How To Test The Igniter -Step By Step (1995-1996 1.5L Toyota Tercel).