So I put my car back on the road after surgery this week, and was out driving down the m62 when the glow plug light starts flashing on the dash, I get home, come onto my favourite forum and find out it could mean that the brake light sensor underneath the brake pedal could be faulty, so me & the boy go outside and with him pressung the pedal there is an intermittent fault, so I think its time to buy a fault code reader which will also reset them once read. I don't have loads of cash atm so found this on eBay. Is it any good for my purposes or do I need something else for my 2002 mk1 asv engined TDI 110hp estate?

http://pages.ebay.com/link/?nav=item.view&id=271398142191&alt=web

It has never done this beforeand it kept going off, could it be because the car was laid up for a month?

You need to replace the brake light switch. £10 ish from main dealer or TPS. Very common failure, & clearing the code won't solve the problem.

Yep as Paul said the light will go off and no fault will be showen once you replace it so no need for the code reader

Okay thats great, how easy is it to change, could a teenager be talked through it as I'm not capable atm?

Yep it's a doddle, literally open the door, pull down the cover, locate the switch above the peddle then twist it one way or the other, don't force it then it should pop out, unclip the switch, attatch the new switch and reverse what you just done less than 5 minute job

When installing the new switch twist it into position until you hear it click. If it doesn't click it won't work. Do not press the brake pedal during fitting. Switch is fit once only so get it right or you'll be buying twice.