Getting the dreaded “Engine System Fault” alert on your Ford Focus can be an unpleasant experience.
This can happen at any time, and it’s not always easy to tell what’s wrong with your car.
In this article, I am going to go over what this message means, the common causes (after working on a few Ford Focus models), and how to fix the issue. Let’s get into it.
What Does “Engine System Fault” Mean on a Ford Focus?
Engine system fault is a generic warning message on Ford vehicles that indicates that a problem has been detected with the vehicle’s Engine Control Unit (ECU).
This could be anything from bad wiring to an issue with the car’s engine itself.
However, after working on a handful of Ford Focus with similar issues and doing a ton of research, I have come up with a list of the most common causes for this warning message.
Ford Focus Engine System Fault Signs
If you are getting this warning message, there are other symptoms you should look out for; these include:
- Your Ford Focus Failing/Hesitant to Start
- “Acceleration reduced” Alert
- Car Jerking When Driving
- Stalling and randomly switching off
- Loss of power and Toque When Accelerating
What Causes Ford Focus Engine System Fault Alert?
Now, let’s look at the most common causes for the engine system fault alert on a Ford Focus.
As I said, there is a long list of possible causes for this issue, but here are some of the most common ones that I have seen:
1. Cluster Soldering Issue:
The primary cause of an “Engine System Fault” in a Ford Focus is often traced to an issue with the instrument cluster (If there are no codes when you scan it).
Specifically the solder joints on the rear of the 30-pin connector.
These joints can fail over time, but the solution is straightforward if you’re familiar with using a soldering iron.
How to Fix
First, you need to gently disassemble the instrument cluster, which includes removing the clocks.
Once you’ve accessed the connector, reflow the 30 pins by applying fresh solder.
After this process, it’s important to clean the entire board.
This can be achieved by generously spraying the board with an electrical contact cleaner and then using a brush to clean each component carefully.
After the cleaning is done, reassemble the instrument cluster (I also recommend replacing the Immobilizer fuse as well), and this should solve the problem.
However, if you’re not comfortable undertaking this task yourself, there are services available online that can do it for you.
For instance, there are individuals on eBay/Craigslist who specialize in this kind of repair.
Simply search for “focus cluster repair” on Google to find them.
2. Bad Glow Plugs
Glow Plugs going bad are also a common cause of an “Engine System Fault” on a Ford Focus TDCI (Diesel Engine).
Glow plugs are responsible for starting the diesel engine when it’s cold outside.
They heat up the fuel so that it can combust properly, and without them, your Focus wouldn’t start or run well at all.
It is possible for your glow plugs to fail or for them not to function properly due to common wear and tear and age.
This can result in an Engine System Fault light being displayed on your Focus dashboard.
If you are getting glow plug-related codes when you diagnose your vehicle, then the culprit is the glow plugs.
How to Fix
You will need to replace the faulty glow plugs and relays; I personally recommend replacing all of them to ensure that the problem does not occur again.
Suppose the issue was caused by faulty glow plugs. Replacing them should fix the engine system fault.
3. Faulty Fuel Pump:
The third most common cause of an engine system fault is a faulty fuel pump.
Your Ford Focus needs an uninterrupted supply of fuel to run properly.
If your Focus is not receiving enough fuel, it will not be able to run properly.
You may get a check engine light followed by “engine system fault” and “acceleration reduced”
Solution
First, you need to be sure that your fuel pump is bad.
One method is to use a scanner to check for any fault codes.
Alternatively, you can listen for the sound that the fuel pump makes when turning your vehicle on, without starting it.
A properly functioning pump should make a sound, whereas a faulty pump will produce no sound or clicking noise.
If the pump is indeed faulty, it should be replaced with a new one.
4. Faulty Injectors
Fuel Injectors on your Focus are responsible for supplying fuel to your engine.
They are located inside the fuel rail, which is a part of your vehicle’s engine.
In order for them to work properly, they must be clean and free from any obstructions
However, Injectors can become clogged, dirty, and damaged over time.
If this happens, they will not be able to supply your engine with proper amounts of fuel as a result, an “engine system fault” alert will come on.
Solution
If you are getting fuel related/Injector codes when scanning your car, then you will need to replace the fuel injectors.
Note: Other things like faulty wiring, bad battery, spark plugs, and coils can cause the same problem. That is why I recommend getting a code reader or taking your Focus to an independent garage or a Ford dealership; however, in most cases fixing the above issues should solve the “engine system fault” problem.
Additional Sources
https://whautorepair.com/is-my-fuel-pump-going-bad-here-are-8-signs-it-is/
https://www.fordownersclub.com/forums/topic/33348-engine-system-fault/
https://www.championautoparts.eu/news/glow-plug-control-module.html