Ignition coil troubles can ruin everything that’s good about owning a Jaguar. Instead of punchy acceleration, you’re left with lacklustre performance. Where once your car was reliable and sporty, it now struggles to start, or worst of all, your engine goes into limp mode. All these scenarios should make it clear that catching ignition coil trouble early is essential. Keep reading to learn more.
Your standard ignition coil is your Jaguar’s version of a transformer. Its sole job is to change low voltage energy produced by the battery into high voltage electricity which can be used by the spark plugs. A basic ignition coil is made up of the following key parts; an iron core, a primary winding, a secondary winding, and electrical connections. There are three main types of ignition coils:
This has two connections on the primary and secondary windings and is used in even cylinder engines.
These feature in four-cylinder engines and have two primary windings and one secondary windings with two connections each.
These are used in engines where one coil is assigned to each cylinder.
The four leading causes of ignition coil failure experienced by Jaguar drivers are:
● Short Circuits: Commonly caused by overheating.
● Faulty Voltage Supply: This is caused by a voltage supply which is low due to bad wiring or weak battery.
● Mechanical Damage: This is usually caused by road debris, collision, or catastrophic engine breakdown, which damages the ignition cables.
● Faulty Contacts: This is commonly caused by humidity.
When your Jaguar’s ignition coils are failing, you are likely to experience the following symptoms:
● engine struggles to start
● frequent ignition misfires
● sluggish acceleration
● power loss
● engine switches to limp mode
● illumination of EML
● generation of fault codes
If you have mechanical experience or are a Jaguar enthusiast, you may be interested in trying to troubleshoot your ignition coil troubles at home. If so, you can follow the guide below:
Connect the diagnostic reader to the 16-pin OBD connector and carry out the following steps:
Select program > Select vehicle > Select fuel type > Select model > Select function required > Select system > Start fault diagnostics
Your Jags’ onboard computer will have sent out specific fault codes which describe the specific nature of the problem.
Prepare the relevant diagnostic tools, such as a multimeter. Find your vehicle’s technical documents, and remove your engine cover.
Before starting diagnostics, give the wiring a visual check. Look out for kinks, wear, and damage which could explain the problem.
Remove the ignition coil from its connectors and measure the voltage. When measuring, you’re looking for a reading that is over 10.5V.
To do this, you need to connect a diagnostic tester to the measurement module of the ignition coil and detach the plug connects form the injection valves and then start the engine. You’re looking for a clearly-identifiable signal.
If you’ve not got to the heart of the problem, you can next remove the coil.
Using a multimeter, you should now check the removed coil. You should measure both the primary and secondary windings.
When replacing the coil, be sure everything fits back correctly and that all connections are reattached.
If your investigations have triggered further fault codes, then you need to make sure to clear them before undergoing test drives.
Undergo a test drive with the diagnostic unit still connected. When this is complete, you can read out the fault memory again to check if your problem is resolved.
If the diagnostic process listed above sounds like a lot of work, you can come to Import Motorwerx where we will undertake the diagnostic work and any repairs necessary. We will consult you with our findings and present you with an affordable plan to get you back on the road safely and quickly. We happily service the communities of Lawndale, Culver City, West Los Angeles, and South Bay, CA. Stop by and say hello or give us a call to find out how we can help you maintain your Jaguar and keep it in top condition.