I have a 1993 940 and I am having problems with the overdrive switch on the gear selector. Occasionaly when I start the vehicle, the overdrive off indicator is lit on the instrument panel (even though it the overdrive off switch was not selected prior to the last shutdown). Pushing the botton doesn't always turn the overdrive back on and it sometimes takes driving th car several miles and pushing the botton on and off to final get the transmission to shift into overdrive.
Where would be the best place to look at correcting this problem

Thanks for your help

Jeff Breeden