Well, I found 5 minutes to check the fluid level in the gearbox today. The level was a little lower than the last time I checked it about 6 months ago so I added half a litre of atf fluid thinking I had found the problem. Unfortunately, it made no difference as the fault light is still on and the engine won’t rev much above 2000rpm or change into top gear. If the weather is ok tomorrow I will see if I can get any fault codes and take you up on your kind offer Mike.