Recently, on the first drive of each day, my 2003 Mazda6 has had trouble properly engaging in first gear. When I first start the vehicle, it backs out of the driveway without a hitch in R, but when I switch to D, it doesn't engage and slides; as a result, I have to let it idle for a while before it will begin to crawl forward; then, I may apply the throttle to accelerate, or move up to second gear, as needed. In two to three minutes, it moves normally, and I have no problems with it for the rest of the day.
Three times already, despite the correct fluid levels, the AT warning light has illuminated, disappearing only when the vehicle was restarted. My car only starts in Park approximately half the time, and I'm wondering whether the problem lies with the transmission range sensor, which presumably fails to detect when the vehicle is in gear and hence fails to electrically engage the appropriate gear. I have a spare sensor, but I'm not sure whether installing it would fix the problem with first gear or the one with starting the engine. However, I just cannot tolerate the ongoing problem with first gear.
Thanks