Volvo: Gear Sensor problem, volvo v 70, position sensors

Question
Hey Ray,
I was currently driving my friend's 1998 Volvo V-70 station wagon.  She had parked on a street that was uneven (the street was a good 3 or 4 inches higher than the sidewalk with a vertical dropoff between the street and sidewalk).  She was boxed in and couldn't get out herself.  She had enough room to get out, but couldn't get the tires over the vertical dropoff between the street/sidewalk.  I know a little about cars and I put my SUV in gear "L" all the time when i want a little more power and to keep the car in a low gear.  I naturally thought it would be ok to do this in this situation.  I put her car in L, gave the car a little gas, and got over the drop off.  After that, she got in the car to drive.  The car would still drive, but it was going really slow, like it was stuck in first gear, and it felt like it was being held back.  The "W" "E" and "S" lights next to the shifter were lighting up and a flashing "up arrow" on the dash was lighting up which signifies a "transmission fault."  I thought it might be that her car was low on transmission fluid or that her filters were blocked up.  After about 30 minutes, the car went back to normal, but we took the car to the shop just in case.  The problem came back to be one with the "gear sensor" and cost about $600 bucks.  Did I do anything wrong?  Was it a problem with the car before-hand or did I do something wrong and wind up break it?  

Thanks,
Blaine

Answer
Blaine,
The gear position sensors have had many failures and is a weak link in the system. It is a switch that gets used each and every time you shift the car, so there is wear and tear each and every time the car is used. The time you had the car was just the last time the sensor was receiving and sending the correct signals. You did not do anything wrong by using a lower gear to move the car, the gear position sensor was just getting weak and failed at that time.