Try the pedal test, all you need to do is put both your brake and accelerator peddle down to the floor (all the way) then turn your key to ignition point but dont start, service light should start to flash, this is your code.... can take a few attempts to read it whilsts its flashing, 10 flashes = 0 so for example i had an egr fault which was code 0400 the service light would flash 10 times then 4 then 10 and 10 again.
once you have the code google search it with engine make and model and you should find what is your problem. hope this helps, wouldn't try diagnostics on a zaffy cos there usless at reading faults! just a word of warning. This works on my 2001 vauxhall zaffy club 1.6 16v. your problem btw sounds like a dodgy egr valve which is common or faulty crank shaft sensor.
Jim Blob
October 2012
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