HELP Engine Light / Transmission light and rough gear changes

[flash20005]

Hi. I have a 1999 VT commodore and a few days ago the engine light/ transmission light came on (I think that's what it is I didn't get an owners manual with it it looks like a little engine with a lightning bolt in the middle). and when the light is on the transmission gear changes are really rough. It was due for a service so i took it in to the mechanic and he did a full service and put it on the computer and there were no faults recorded. The light doesn't come on till you have been driving for around 10 mins so the mechanic never experienced the problem first hand. Am really worried that there might be something really wrong with my transmission and the clunk sound that happens with gear changes is really discerning. Does anyone have any idea what may be causing it???
Thanks

[sxc_sound]

Just check the oil levels to start with. From there...maybe get it looked at by a transmission place

[XStatic64]

Did he check your transmission fluid too? I would be taking it to a trans/diff shop to get serviced and looked at.

[BlackVXGTS]

Possibly a shift solenoid or TPS problem. When the problem occurs, slow down and manually shift into first gear. Accelerate to around 10kph or so and then slow down a couple of times. If the transmission automatically changes into second during this process it's probably a TPS problem.