MK4 Golf GTI - Check Engine Light

[Herbie58]

The check engine light has just lit up on my Mk4 (2000) Golf GTI. The car has just had a full service, full oil change, filters changed, cam belt and timing belt replaced, brake pads and discs changed. I'm a bit lost as to what could be causing this.

I've heard that stupid things can cause the check engine light to come on, but equally as many horror stories. Has anyone else experienced this and am I about to be hit with a sky scraper bill?

Cheers!

[cuprabob]

Probably the coolant sensor, very common

[Matt_N]

Could be a number of things:

MAF
Coilpack
Boost / vacuum leak
Lambda probe
Etc...

You'll need to get the code read really, or get a code reader off of ebay and read it yourself, the U280 is an OBDII reader available for around £20 on ebay and works fine, I bought one the other week.

[Tame Technician]

You say its just had a full service including the belt.

How just, like literally just or a few weeks ago. It is posible to mistime the belt ny one tooth, the engines run fine but it puts the light on because the cam and crank sensors are mistimed. Also I've known the apprentises leave MAF sensors or ACF solonoids unpluged after doing air filters. But this would happen almost straight away, if any time has passed it wont be anything to do with this.

Take it back to who serviced it, explain the light is on and ask them to read the codes. If its anything to do with cam and crank sensors, point out that this could mean they did the belt wrong.

If its somthing comletely unrelated however its not there fault at all and you will to pay for it. Getting the fault codes check is the first port of call either way.