Q: I have a 2006 Suzuki Grand Vitara, four-wheel-drive, 2.7-liter, six-cylinder automatic transmission. The car has 70,000 miles, and I am having a problem with the transmission. On occasion, the transmission will shift hard between first and second gear. This does not matter if it shifts at 2,000 or 5,000 rpm — same jolt when it shifts. All the other gears shift smoothly. The second problem is that, on occasion and usually in third gear, the transmission will not shift itself until you completely take your foot off the throttle. The car will not shift even with light pressure on the throttle; it just winds out. After releasing the throttle, it shifts smoothly. This does not happen if the outside temperature is below about 50 degrees. The car developed this problem in the summer, continued through fall and only acted up on the couple of warm days this winter. I changed the transmission fluid at 50,000 miles and then again at 63,000 when the problem developed. One transmission shop drove the car with a computer connected and told me that all is well. Their advice is to get the transmission reprogrammed. I have yet to find anyone, including the dealer, that has the software to reprogram this transmission. I would appreciate any thoughts or suggestions.
A: The Grand Vitara actually has a reputation for this problem. I am surprised your transmission shop was not aware of the range position sensor problem. The range position sensor sends a signal to the computer and reports the gear selected by the driver. Intermittently, the signal coming out of the range position sensor becomes garbled. Thus the computer doesn’t know what the driver is looking for. It’s similar to someone talking to you in a language you don’t understand; you don’t know what they are talking about, right? The transmission shop has to monitor the signal from the range position sensor as an electric pattern (sine wave) rather than looking at numbers. They should notice that, when they wiggle the shifter a little bit, the signal gets garbled. That’s a sure sign the switch has gone bad.