Engine Management light on your dashboard?

Posted by Thame Cars on Jan 17, 2020 12:44:00 PM

engine watning light diagnostics

The most common fault light to illuminate on car dashboards is the engine management light. For many motorists it may as well look like a flashing pound sign, accompanied by an annoying voice passively bleating ‘well this looks expensive, doesn’t it!’. 

Something about the mystery of car electronics can make us feel like we’re at the mercy of the local garage, and about to get well and truly ripped off. 

But the good news is that there are a number of different reasons for triggering the warning light, and they’re not all going to require remortgaging the house. 

For over 20 years now, new vehicles have been fitted with on-board diagnostics (OBD) systems that sit on the engine and monitor the car’s vital signs. 

A stream of information on the function of your ignition, engine, gear box and emission systems passes through the OBD every second, which checks it against various parameters for likely problems. 

If such an issue is detected, rather than allowing it to continue uninterrupted as it would previously have done in the pre-OBD days, it triggers the little engine light on your dash. 

With all the things that could go wrong these different systems you’d be forgiven for thinking that this was a relatively blunt method for announcing that there’s trouble ahead. 

It’s a bit like being told by the doctor that you’re ill, whether you have grazed knee, a broken collar bone or full-blown man-flu. 

Fortunately the ones who design these things have thought of this, and there is a more finely tuned diagnostic system beyond simply announcing ‘Housten, we have a problem’. 

If you happen to have an OBD scanner lying around, you can plug it and obtain a code that will tell you more about the location and nature of the problem. 

It’s possible to buy one of these scanners for under £40, though professional spec scanners are more likely to retail for £2000. 

Let’s be honest, you’re probably not going to do this, but if you did, you’d get a 5 digit code including a letter. The letter tells you the location: P = Powertrain, B = Body, C = Chassis, U = Network. 

Then there’s a couple of numbers that gets you closer to precisely where the fault is located, and the final 2 digits are a code for the nature of the fault. 

But guess what... without an up-to-date key it’s impossible to accurately decode what these digits mean, so even if you bought yourself a scanner, figured out where to plug it in and got the code, you still wouldn’t be any the wiser with what the problem was. 

Here at Thame Cars we’re forever sharing our knowledge on how to maintain your car, take care of your tyres, and the regular checks you should be making. So it drives us a bit mad that these things have been made so un-user friendly but it is what it is. 

The long and the short of it is that if you want to get to the bottom of why your engine management light has illuminated, you need to take it into a garage and have them run a diagnostics test with their all singing, all dancing fancy OBD scanners. 

The good news here is that they’ll very quickly be able to get to the nub of the problem and give you accurate information about what needs doing to rectify it. 

Not all issues will be expensive to fix or even need dealing with right away. But problems can start to stack up if you ignore the warming light.

This check is usually run as a part of an annual service, but if your light has come on between services it’s worth booking in for a check. 

If your light is on and you want to get to the bottom of what’s triggered it, simply book your vehicle in for an engine management light check online today, or contact our service department on 01844399383. 

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