Four problems related to automatic transmission have been reported for the 2004 Infiniti G35. The most recently reported issues are listed below.
Reporting a sudden acceleration. Came to a stop (traffic light)suddenly the engine roared and the car took off with full speed. Hit a van at the drivers side backwheel area. The car was totalled. The insurance CO. (21st century) hired an engineer who did not find any fault with the engine. . This happened 2 times before. I complained to the dealer they could not duplicate the problem either before. Looked on the internet . Several drivers had the same terrible experience. (allworldauto. Com /2004infiniti G35 user comments/complaint) I am reporting this before someone will die.
Several times when driving my 2004 Infiniti G35x, the car will accelerate when I downshift in the "tiptronic" mode from 3rd to 2nd or from 2nd to 1st. Although this has not caused an accident, I wanted to provide this information to you as I am not sure if this is the way the car is intended to operate. This condition would potentially cause an accident at an low speed (30 miles per hour or less) where the driver was not expecting the car would "lunge" forward when downshifting with a tiptronic transmission.
While driving, the transmission would not function properly. When picking up, the vehicle will hesitate in accelerating.
The vehicle rolled back on its own when parked on an incline. The vehicle engine was off. The consumer was able to duplicate the failure on ice/snow but not on dry pavement. The second time the vehicle rolled backwards with the parking brake on.