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Theres a fault code from one of my car’s sensors or the main ECU- can your garage help?

As a lot of drivers will already know, under the bonnet of our cars, if we drive a modern vehicle that is, will be a mass of electrical sensors.

Depending on which car you drive, will depend on how complex the sensors within your car are. Yet, the ECU combined with each sensor play an important role in helping to detect problems with our cars, and sometimes let us know via the car’s dashboard when somethings is not functioning correctly.

The warning lights on some cars can therefore be displayed for a wide range of different reasons, ranging from the coolant running too low, through to a problem with the cars exhaust causing emission issues or DPF problems. Each time we therefore turn on the ignition, our cars ECU starts work on monitoring various sensors which often are checking critical parts of our cars, to check if things are running as they should.

So, this could range from the oxygen sensor, making sure the air mix is right, through to checking the emissions are within tolerance.

What’s important is not to ignore any fault code or error warning message, as if not checked the fault could get worse, sometimes leading to catastrophic engine failure. Let’s give you an example, an error code may appear on the LCD panel, or let’s say the dashboard on some cars, it may just simply state “error” and a code on some cars, yet it could, depending on the make and model of the car, relate to somethings that’s critical for the efficient running of the engine.

Other problems that our cars ECU can notify us about problems with other car parts such as fuel injector issues, problems with the fuel and even if the cars miss-fires, what your car’s ECU is monitoring depends on the make and model of your car, yet, most modern cars have a lot of sensors.

My cars displaying that it has an “ECU Error” and won’t turn-over at all, what does this mean?


A cars ECU is like the brain of the car, so just like an onboard computer, it will therefore be carrying out a lot of calculations as you drive down the road to improve the running of the car.

The ECU may sometimes makes adjustments for you, for example if the fuels running too lean, it may, depending on the make of the car, change this to improve the efficiency of the engine.

However, if it’s the actual ECU that’s incurred a fault, and is not allowing the car to start, you may wish to call us, so that we can collect the car for you.

Will the ECU need to be replaced?


If a fault code is being displayed, then it could be to do with an individual sensor that’s detected a problem with lets say for example, a DPF problem, so even though the dashboard may say there’s a fault, it might not be the ECU itself.

It could just be a car part that’s relaying the fault or sometimes a problem with the sensor itself.

Errors can be displayed on a dashboard for a wide range of reasons, for example it could be something as simple as a clogged air filter, or something as complex as the engine severely overheating, so what’s needed is for our mechanics to use diagnostic equipment which communicates with the ECU directly.

The ECU if working correctly then should flag fault code(s), then our car diagnostics will be able to tell what the issues are exactly, so that they can be fixed by one of our mechanics in Cardiff. If it’s the actual ECU unit that wont communicate, as is essentially shut-down and wont communicate with diagnostic equipment, then it might be a case that the ECU is at fault.

What if we just clear the fault codes, will this fix the problem?


The simple answer is no, its like papering over the cracks when decorating, what should really happen is a good quality car diagnostic equipment should be used, no clearing of fault codes should occur until a mechanic has a good understanding of the faults, and what’s causing them, and how to prevent them recurring.

For example, just ignoring a fault code, by simply deleting it, could mean that a major fault is missed, then this could lead to major engine problems later on quite possibly.

Is your car displaying a fault code?

With some cars the fault code will appear on the cars central LCD screen, with some other cars it may simply be on the car’s dashboard, however, whichever car brand that you drive, you most definitely shouldn’t ignore any warning lights or error codes on your car.

If you’re looking for a local mechanic who can repair a problem with your cars ECU, or electrical sensors, then why not give us a ring today?

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