Happy New Year, Happy New MOT

As of the 1 January 2012, the MOT test we all know and love will change. No I am not talking about the government consultation exercise mooting a possible change to 4-2-2 frequencies, that would be opening another can of worms entirely. What I am referring to is the technological evolution of the test that will see our belovedly idiosyncratic MOT stretch itself to incorporate an MIL survey. That’s a Malfunction Indicator Lamp check to you and me.

This will call for the examiner to visually check that warnings lights for ESP, SRS, ABS, TPMS and TTFN (…alright not the last one!) are not permanently illuminated. This will come into effect from 1 January but will be highlighted as an advisory item only until 31 March. From 1 April onwards, vehicles will fail an MOT if these lights are illuminated. Warnings lights or MIL that are to be noted if illuminated include ESP; Electronic Stability Programme, SRS; Safety Restraint System, ABS; Anti-Locking Brake System, and TPMS (Tyre Pressure Monitoring System).

The good news for those who have not yet invested in much in the way of diagnostic kit is that this is not required to carry out the visual check of these warning lights. However, a diagnostic scan tool can read the fault code and establish the precise problem, allowing garages to then fix the fault and proceed to reset the warning light. Or in other words it helps you get the job done quicker. Various versions of this equipment is available from a range of suppliers (more on this next month February’s Tyres & Accessories, which includes a special section on diagnostic systems and equipment).

There are two interesting aspects of this rule change. Firstly there is the broad fact that the new rule is indicative of how electronic cars of today are becoming. When it comes to the safety and performance gains things like ESP and start-stop technology offer, this is obviously a very beneficial thing. But the downside is the increasing prevalence of the invisible fault – something I experienced much to my chagrin on the way home from my Christmas holiday when my normally reliable engine cut out for no apparent reason. The “very nice man” from the AA was none the wiser either, resulting in a 300 mile tow back to the other side of the country. Not the happy New Year I was looking for. In addition this general dependency on electronics also means vehicle manufacturers and franchise chains are increasingly able to control repairs and servicing through the requirements for specific software and virtual system upgrades. But I digress…

The second aspect is related, but more specific. With the advent of this new rule, the formerly straightforward task of changing a tyre could change forever. From 2012 TPMS systems will be fit as standard to all new cars and many of these will use direct pressure sensors that are a) delicate and b) system specific. Each time a tyre is changed on one of these systems the appropriate system instructions will also have to be fed back into the system. True, many new cars will be running indirect systems which calculate pressure based on wheel revolution data sent to it by ABS and ESP electronics, but these can often cause problems too. In my experience, for example, a dodgy system can flag up under pressure tyres (that were in fact OK) for apparently unknown reasons or because tread depth was higher on one side that the other.

What’s this got to do with the MOT? I am glad you asked. Failure to reset such systems properly after fitting tyres will result in the car’s dashboard displaying a TPMS light, which – you’ve guessed – could result in an MOT fail. So when you raise a glass to wish your family, friends, colleagues and customers a happy new MOT. It’s not just another year older; it’s getting more complicated too.