Hi there,
I purchased a Lumina Model 2000 a month ago and was very much happy.
But all my excitement turned into deep worries when experienced the
transmission problem in it. The exact problem is:

10 Days back- The gear will shift from 3-4 at about 100 Km/hr @ 2300
RPM but after a short while (say 3-5 km distance of drive), it comes
back to 3rd . The RPM Goes to around 3000. If I stop the car, turn off
ignition and restart the journey again, it picks the 4th Gear but again
disengages after a few kilometers. Again stop , turn off the ignition
and it picks the 4th gear and so. But if I stop and do not turn off the
ignition, and restart the journey , it will not swith to the 4th gear
at all.

5 Days back- Gear will not switch from 3 to 4 at all. The car runs in
3rd gear. RPM is 3000 at 110 Km/hr speed.

Car switches smoothly from 1 -2- 3 gear. No jerk or problem.

I checked from a Local Workshop. We
Checked the gear oil. Oil was clean and not very much thick or viscous
because of debris ot so.
Dismantled the bottom oil pan.
Gave supply from the batter to each of Solenoid valves and listened the
"click sound" means these were working.
Replaced the Gear oil and filter.
The problem was still the same. Car switches 3-4 but disengages again
after a few kilometers traveling.
2 days back- Car is not shifting to the 4th gear at all.

Yesterday, I went to a local dealer here who checked it with his
"Tech-2", telling me that the code it is telling is "P0085-
Transmission Slipping".
He again checked al the solenoid valves by giving them supply. Replaced
gear oil and filter.
The car shifted from 3-4 but again after a few kilometers switched back
to 3rd gear. So the same situation.

I want to know what is the exact problem in the transmission. Is it a
mechanical defect or electrical.
The dealer is asking to overhaul the gear box. If there is a mechanical
defect, why it engages when I turned of the ignition? To me it looks
like some communication problem to the transmission. I need your kind
advice before taking a expensive decision of dismantling the gear box.
I will be highly obliged for your kind advice on that because in this
part of the world, a correct advice is very difficult.

My email address is logic123@emirates.net,ae

Thanks and Regards,