One problem related to cruise control has been reported for the 2004 Toyota Avalon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Avalon based on all problems reported for the 2004 Avalon.
My daughter was in a car accident in Dec 2013 involving our 2004 Toyota Avalon. We suspect the cruise control did not release as it should have. She had been using the cruise control and tapped the brake to release it as she exited a highway she then stepped on the brake to slow down as she exited the eastbound highway to maneuvere the exit curve to merge onto a southbound interstate highway. On the curve she noticed the car wasn't slowing down as it should, and when she braked harder, the brakes locked up sending her into a swerve. The car traced a path similar to an upside down question mark. She crossed two lanes, and the rear of the car hit a wall landing her facing traffic right next to the roadway. When the car came to a stop, both the gas pedal and the brake were completely depressed to the floor, and the engine had shut off. Her foot had not been on the gas pedal for some time since she was using the cruise control. The insurance company totaled out the car. Thankfully, there were no other cars involved, but my daughter was pretty shaken up and had to be treated for headaches/neck soreness due to whiplash. When she restarted the car (she had to turn the key off first, then on), the pedals returned to normal and she was able to move the car across to a safer location on the shoulder of the road to await help. Toyota's gas pedal recall started with the 2005 Toyota Avalon, so we had no recourse for action and the car is now gone, so there is no evidence to inspect. We are convinced the gas pedal sticking / cruise control refusing to release was the cause of the accident and want to pass on the information so that others can be protected from injury.