There are to be some changes to the MOT test from 1st January 2012 which are being introduced in response to European Commission Directive 2010/48/EU of the 5th July 2010 and which will effect those with aftermarket HID headlights and remapped ECUs:

4.1.4 Compliance with requirements:
(a) Lamp, emitted colour, position or intensity not in accordance with the requirements
(b) Products on lens or light source which obviously reduce light intensity or change emitted colour
© Light source and lamp not compatible

4.1.5. Levelling devices (where mandatory):
(a) Device not operating.
(b) Manual device cannot be operated from driver’s seat.

4.1.6 Headlamp cleaning device (where mandatory):
Device not operating.

For anyone with a remap, section 6.1.9 may be relevant.

6.1.9 Engine performance:
(a) Control unit illegal modified.
(b) Illegal engine modification.

(by 'illegal', it is assumed that they mean changed/programmed differently from OEM specifications)

There will also be a new check on the general condition of the wiring:

4.11. Electrical wiring
(a) Wiring insecure or not adequately secured.
(b) Wiring deteriorated.
© Damaged or deteriorated insulation

and on the function of airbag and seat belt pre-tensioner systems:

7.1.4. Safety belt Pre-tensioners:
Pre-tensioner obviously missing or not suitable with the vehicle.

7.1.5. Airbag:
(a) Airbags obviously missing or not suitable with the vehicle.
(b) Airbag obviously non-operative.

7.1.6. SRS Systems:
SRS MIL indicates any kind of failure of the system.

Originally Posted by VOSA
The car/light goods vehicle MOT test is about to change – the European Commission has changed the Directive that covers it. We take a look at when these changes are likely to come into effect and what they mean for MOT testers.
Britain has been testing vehicles under the MOT scheme for 50 years now. Last year, the European Directive covering the MOT test was updated and revised by a modern version called 2009/40/ EC. This was then updated by 2010/48/EU, which was ratified on 5 July this year.
The new Directive keeps the EU minimum 4-2-2 test frequency but adds a number of new elements to the British MOT test. The Directive anticipates all test changes being in place by 1 January 2012, and a common European approach to test certificates in place by 1 January 2014. So what is VOSA doing to introduce the changes?
In terms of test frequency, in mid-July the coalition government confirmed that it intends ‘to look at the issue of MOT test frequencies later this year’. VOSA contributed statistical data to inform the last review in 2008, and we expect that our computer system and the data you have entered will be utilised again in much the same way.
We expect to hear more details of the government’s review proposals later in the year.
As far as changes to the test content are concerned, VOSA has already been analysing the requirements of the new Directive and working out how to implement them. We started this earlier in the year by talking with representatives of the MOT trade at our regular Trade User Group and VTS Council meetings. Both VOSA and the Department for Transport (DfT) are keen to ensure that any changes to the test are introduced in as practical a way as possible, keeping the burden on the trade to a minimum and ideally keeping the changes cost neutral.
In many cases, the changes shouldn’t necessarily lead to an increase in average test times. A good example is the malfunction indicator lamps on the dashboard that indicate defective electronic power steering, electronic stability control and secondary restraint systems. Testers already check the dashboard for other lamps, so no extra time would be required for this addition to the test.
Electrical wiring and batteries are now included in the test’s scope, but testers already check the vehicle structure where wiring is secured – often along the same routes as other testable items, such as brake pipes in the engine compartment. So again, this doesn’t look like an additional burden on the tester. In the pre-computerisation days, testers often (wrongly) failed vehicles for insecure batteries, so they must have been looking at them then! Now, it means that when we implement the new Directive, vehicles can legitimately fail for battery insecurity, for no extra tester effort.
Other items – such as headlamp bulb and unit incompatibility, headlamp levelling devices and illegal engine ‘chipping’ – will need further thought before we can get a workable solution for MOT stations.
Some of the new items may require extra effort on the part of the tester – when we know for sure what that is we’ll be talking again with our trade and DfT colleagues to work out what the impact will be.
The common EU test certificate should be relatively easy to achieve – the only data that the Directive expects and that we don’t currently provide is the symbol for the vehicle’s country of origin. Probably 99% of vehicles tested will have
‘UK’ entered here, but if you do test vehicles with a foreign plate, you will need to enter the correct country symbol. We may even be able to make this change earlier if there is a convenient opportunity.
The MOT trade can rest assured that VOSA is working closely with you to introduce any new elements as efficiently and effectively as possible, with the minimum of fuss. Just as importantly, we are also working closely with Siemens to ensure that any system changes due on New Year’s Eve 2011 go smoothly! We should know more by the time the MOT seminars take place – come along and ask the experts.

Conclusions

HIDs are not technically legal as a retrofit, but they will currently pass an MoT inspection. There are definite advantages with respect to light power and lower heat generation, but getting a good light beam pattern may require the use of a dedicated projector unit, pushing up both cost and difficulty of the installation. After having given the topic a great deal of thought, I have not gone down this route. But then I live in a city with widespread street lighting, so the performance of the dipped beam is rather less important than if I lived in the countryside. Whether you should fit these bulbs has to be your decision, but my opinion is to edge against it.

Neosophist wrote: So in conclusion, if your going to convert use a projector housing. I've helped people build light units with projectors and they have produced good results! Not so good if you find out they'll be an MOT fail in 6 months.. but in Thailand you can get away with it!

IF not get some bright H4's.. you can get 100/60watt or even higher spec 'rally bulbs'

Conclusions

HIDs are not technically legal as a retrofit, but they will currently pass an MoT inspection. There are definite advantages with respect to light power and lower heat generation, but getting a good light beam pattern may require the use of a dedicated projector unit, pushing up both cost and difficulty of the installation. After having given the topic a great deal of thought, I have not gone down this route. But then I live in a city with widespread street lighting, so the performance of the dipped beam is rather less important than if I lived in the countryside. Whether you should fit these bulbs has to be your decision, but my opinion is to edge against it.

The most dangerous part of the attempt to "retrofit" Xenon headlamps is that sometimes you get a deceptive and illusory "improvement" in the performance of the headlamp. The performance of the headlamp is perceived to be "better" because of the much higher level of foreground lighting (on the road immediately in front of the car). However, examining isoscans of
the beam patterns produced by this kind of "conversion" reveals *less* distance light, and often an alarming relative minimum where there's meant to be a relative maximum in light intensity. When you *think* you can see better than you can, you're *not* safe.

It's tricky to judge headlamp beam performance without a lot of knowledge, a lot of training and a lot of special equipment, because subjective perceptions are very misleading. Having a lot of strong light in the foreground, that is on the road close to the car and out to the sides, is very comforting and reliably produces a strong *impression* of "good headlights". The problem is that not only is foreground lighting of decidedly secondary importance when travelling much above 30 mph, but having a very strong pool of light close to the car causes your pupils to close down, *worsening* your distance vision...all the while giving you
this false sense of security. This is to say nothing of the massive
amounts of glare to other road users and backdazzle to you, the driver, that results from these "retrofits".