VIDEO: Navigating the Ignition Coil Connector

VIDEO: Navigating the Ignition Coil Connector

Always check the wiring diagram to confirm the connections to the coil. This video is sponsored by Standard Motor Products.

CC: Two-wire ignition coils such as this Mazda coil, use an externally mounted module, or power stage, for controlling the primary current. 

To scope this signal, you can tap into the circuit, but make sure you use an attenuator, so the inductive kick does not damage the scope. You can also use a current clamp on one of the wires to see the switching of the driver circuit and whether the primary current is reaching saturation. On two-wire systems, chances are the ignition module is measuring dwell and burn time through the power and ground in the module.

If you have a three-wire coil such as this Honda coil, you will have power, ground and, depending on the manufacturer, a third wire called the command signal. In this type of coil setup, the power stage is inside the coil.

If you measure the power and ground, you will see 12 volts with the key on. With the engine running, you will see small voltage drops as the coil fires. If you use a current clamp, you will see the switching of the coil with greater definition.

The signal wire will typically have a voltage of 5- to 7-volts that will switch on and off, commanding the internal module to open and close the primary circuit.

If you are using a two-channel scope, graph the current and signal wire.

If you have a coil with four wires like this Audi coil, use a wiring diagram to figure out what the manufacturer is doing with the fourth wire. The majority of the time, it is a ground. But some ignitions have an inductive coil to measure coil performance by the engine control module.

Always check the wiring diagram to confirm the connections to the coil. Also, with the wiring diagram you can determine the module with the ignition coil driver. In some cases, you might find that all the coils are fed ignition voltage with the same power source.  Using a current probe on that wire will allow you to view the current drawn on each coil from one connection.  This will allow you to see “known good” signals as well as the faulty one you are trying to diagnose.  As a bonus, you can find the ground connection or connections for the coil. This can be a big help during a no spark diagnosis.

This video is sponsored by Standard Motor Products.

You May Also Like

EV Safety Basics on the Shop Floor – Part II

As long as you follow the EV guidelines, you are going to have to use the proper PPE and insulated tools.

Staying safe while working on an electric vehicle requires the correct shop equipment as well as the correct personal protective equipment (PPE) and shortcuts are simply not an option. Let’s take a look at everything you are going to need.

We’ll start with PPE and electrical safety gloves. Class zero electrical insulating gloves rated for 1000 volts are required for EV service. Simply put, these gloves prevent high voltage from traveling through your hands, and they must be tested every time you use them by checking for a pinhole or any damage that could allow voltage to pass through a glove. A glove inflator is the most efficient way to do this. Insulating gloves must also be clean and dry so there are no conductive substances that can allow high voltage to travel outside the glove to your arm. Treat these safety gloves with extreme care. They can be damaged easily and they’re sensitive to UV rays, so they should be stored in a dark, dry environment. A ventilated UV-resistant bag is the best option. Safety gloves must also be re-certified every six months. You’ll also wear them with a leather outer glove to protect them, most prefer to wear an inner cotton glove as a liner to allow your hands to breathe.

VVT Sprockets and Solenoids

Advanced engine management systems like VVT play a crucial role in achieving this balance by allowing for dynamic adjustments to valve timing.

EV Safety Basics on the Shop Floor – Part I

It’s critical to utilize OEM service information and procedures for each and every hybrid or EV.

Empowering the Automotive Aftermarket Through Collaboration

Distributors, manufacturers, training institutions, associations and service providers all help automotive professionals stay ahead in a market that is constantly evolving with new technologies, trends and customer demands.

Understanding LSPI & Engine Oil

Using the correct manufacturer-recommended oil is crucial for peak performance and long-lasting engine health.

Other Posts
Serpentine Belt and Drive System Maintenance

Properly maintaining the entire drive system prevents premature belt wear and system failure, ensuring customer satisfaction and vehicle reliability.

Randy Breaux, Group President, GPC North America, Talks to AMN Drivetime

At NAPA, “Breaux Knows” business relationships, ABCs to avoid, and serving the automotive professional.

How Modern Car Sensors Optimize Performance and Emissions

Learn how Standard ensures accuracy, speed, and durability in their sensors to maximize engine performance and efficiency.

Five Tips for your Next Wheel Bearing Job

These practical tips are designed to save you time and frustration, ensuring a smooth, noise-free outcome for your customers.