Two problems related to transmission gear slipping have been reported for the 2004 Saturn ION. The most recently reported issues are listed below.
Transmission slips gears when driving down hill. Consumer does not have to depress the accelerator or brake pedal. Vehicle will just slow down to 10 mph. While driving up the hill vehicle will accelerate up to 25 mph.
While accelerating, the vehicle down shifted. The consumer was able to maintain control of the vehicle and drove it to the dealer for inspection. The mechanic informed the consumer that the transmission chip needed to be replaced. The problem recurred and was taken back to the dealer four times. The mechanic was unable to duplicate the problem. On numerous occasions the vehicle did not shift properly. The vehicle would feel as if the transmission was slipping. The rpm would go up but the vehicle did not accelerate and no problem would be found by the service dealer. The consumer had almost experienced 2 rear end collisions and 1 broadside collision.