2004 Toyota Sienna: adaptive cruise control problems

Filed Dec 17, 2019 · 125,520 miles · WA

Unintended acceleration problem. Two episodes, months apart, both at very low speed. Was stopped behind two cars. Two cars in front started up to go through intersection. I took my foot off the brake and moved it to the gas pedal. Car started up normally. Then a child pushed to crosswalk signal which started to flash. I moved my foot to the brake pedal, and the car started slowing down normally, but then the car suddenly lurched forward. Both I and the passenger thought we had been rear-ended (but there was no car behind). It was a similar feeling to when the cruise control kicks in to accelerate, but no cruise control had been activated. I took my foot off the brake and slammed it back on the brake, and the car stopped. The previous episode had a similar series of events.

Filed Dec 31, 2013 · Acceleration, Fuel system · 146,455 miles · MD

I attempted to merge onto the expressway and after pushing the gas pedal the van suddenly accelerated beyond my control. I eased off the pedal and the van continued to serge ahead with no way for me to stop or slow it down as the brakes would not work. I saw the RPM reach level 6 and speed increase to 70 in seconds but as it was the expressway, I was able to keep my distance from cars in front of me. I switched the lever to the neutral position and the van slowed down and then I went back to drive and it roared back up to 70 MPH with the RPM again at 6 and I tried turning the cruise control on and then braking to see if it would shut down the gas but no luck. I went back and forth from d to n for about 2 minutes and then on one of the movements from n to d it shut down back to normal. I dropped the van off at my toyota dealer the next day and am waiting to see what "headquarters " decides.

Filed Mar 3, 2010 · Acceleration · 25,000 miles · AZ

Tl*the contact owns a 2004 toyota sienna. While driving with the cruise control engaged and the vehicle accelerated beyond the set speed. When the vehicle will decreased in speed the sensors detected another vehicle approaching. The contact switched lanes and the vehicle would start to accelerate up to 10 MPH beyond the set speed. After the vehicle has passed the approaching vehicle, the vehicle will decrease back to the set speed. The contact has not contacted the manufacturer. The failure mileage was 25,000.

Filed Feb 24, 2010 · Acceleration · 30 miles · 00

Our family purchased a brand new 2004 toyota sienna awd and had countless issues with it . The most serious issue was - random unpredictable acceleration responses. We contacted toyota canada & japan in 2003. There is absolutely 100% no doubt in my mind, or my wife's mind, that the toyota product line has something wrong electronically in their accelerator pedal or transmission sensors - or the software that interfaces with them. We did not have sticky gas pedals or floor mat issues - we had a vehicle that didn't operate the way we were asking it to. The vehicle never consistently responded to the actual pressure being placed on the accelerator pedal. A light press in parking lot driving would sometimes result in what felt like full throttle acceleration and when trying to turn across traffic at an intersection, or during merging - the vehicle would hesitate and then move the vehicle when it was no longer safe to do so.. Toyota said " they did not consider this behavior a safety issue " it was only " a nuisance problem " . First our dealership ignored the problem. Then they said " my wife didn't teach the vehicle to drive properly - it had a smart learning transmission you know " . They finally admitted there was a problem after we continued to voice our concern over several near miss incidents with the vehicle . In one incidence , while on the highway using cruise control - the vehicle unexpectedly accelerated full throttle into a corner at over 140 kph forcing us onto the shoulder and almost off the road . It was a nerve shattering experience. Our toyota dealer finally admitted a similar acceleration problem existed in the camry / corolla lines and that it was transmission software related . After several months of the run around from toyota with no fix in sight - being told by the owner of the dealership to drive the vehicle in 3rd gear to minimize the surges until a software fix was created - we walked away from the vehicle.

Filed Feb 18, 2010 · Acceleration · 73,099 miles · PA

Tl*the contact owns a 2004 toyota sienna. While the contact was driving 70 MPH using the cruise control the vehicle suddenly accelerated without warning. The contact had to apply extreme pressure to the brakes and engage the emergency brake to stop the vehicle. The contact noticed prior the failure that the vehicle would surge without warning whenever traveling up an incline using the cruise control. The vehicle has not been diagnosed by the dealership. The current and failure mileages were 73099.

Filed Feb 7, 2010 · Acceleration · 30,486 miles · TX

I suspect the cruise control of my 2004 minivan toyota sienna ce has similar issue found in recent prius reports. 1. When cruise control is used on uphill road conditions 2. The speed can be accelerated to over 5 miles/hr more than the cruise control setting. For example, when I set the speed to 70 miles/hr, at a little longer uphill road, the speed will drop first (like 67miles/hr) and then accelerate in order to get back to 70miles/hr speed target. But the cruise control system continue accelerating after passing 70 miles/hr and could be as high as 75miles/hr. 3. Nothing had been done, just be cautious by myself. After reading similar complaints on prius of toyota, I feel this may be the same issue.

Filed Feb 3, 2010 · Acceleration, Driver assistance · 1,500 miles · GA

2004 toyota sienna xle limited- uncontrolled cruise control acceleration/deceleration. The problem has continuously occurred since purchase in september 2004. Dealership denies problems. Dynamic cruise controlsystem causes my car to dangerously accelerate and decelerate. When laser detects nearby vehicle, the car will brake abruptly. Likewise, once the nearby car is no longer in laser range, the car will accelerate abruptly to return to the set cruise control speed. I have almost been hit from behind multiple times on freeways because of the abrupt deceleration. I have been caught off guard several times by the acceleration and nearly lost control of the vehicle. The only way to stop the rapid acceleration and deceleration is to press the brake in order to disengage the cruise control system. I have never driven a car with such a dangerous cruise control system. I no longer use my cruise control system because I fear that I'll be unable to disengage the system and lose control of the vehicle.

Filed Dec 7, 2009 · Acceleration · 85,000 miles · WI

Failure of the adaptive cruise control module on a 2004 toyota sienna xle limited. The adaptive cruise control module, located under the front bumper on the passenger side, fails completely and continuously resulting in complete failure of the cruise control system. The module is not sealed properly thereby allowing moisture inside resulting in corrosion and failure of the part. When actuated, the part is designed to automatically slow the vehicle while approaching slower traffic from behind. Failure of this part while driving could result in an accident if the module does not automatically slow the vehicle properly. The vehicle in question has only 85,000 miles on it. The vehicle has 88,000 miles on it know. The vehicle was taken to kelso toyota in appleton, wi where I was told that the unit need to be replaced. I disassembled the unit and found the corrosion. I believe the deal would simply replace the unit with new and then discard the old unit not knowing why it failed. I believe the wrong oring material was used. I believe in cold weather the oring shrinks allowing water into the modules cabinet resulting in the failure.

Filed May 29, 2007 · Transmission · FL

Vehicle has had a transmission hesitation problem since we purchased it. The delay consists of a 2-3 second delay before the acceleration kicks in. This occurs when merging, turning or attempting to speed up to avoid collisions/objects. We have reported this problem to the dealer every time we bring it in for maintenance, with no improvement in performance. Additionally, under cruise control, the car "skips" gears unexpectedly and revvs randomly.

Filed Sep 12, 2005 · Acceleration · 6,000 miles · MO

Referring to our 2004 toyota sienna purchased in aug, 2004, three times, when using the cruise control and engaging the "resume" function, the vehicle accelerated at full throttle and continued doing so past the set speed until stepping on the brake to disengage the cruise control. This resulted in the speed increasing to 5 to 10 miles over the set speed. This is very dangerous and could result in a crash if another vehicle suddenly pulled out in front of my vehicle.

Filed Aug 12, 2005 · Acceleration, Electrical · 22,000 miles · CO

Radiator ruptured and the engine overheated; hose replaced in steering column recall; rust protective tape recall; dvd screen replaced and the entire dvd player replaced(screen still not easily visible in middle row); passenger seat belt replaced; middle passenger seat belt failing; gasoline smell inside of car with AC on recirculation; driver's window fell inside door in snow storm and was not considered a safety issue to get a loaner vehicle even though the vehicle could not be locked; tires completely bald and leaking under 30,000 miles, dvd player must be at a high db volume and when returned to radio/cd will almost deafen you; interior lights have to be manually over ridden or will drain battery; car hesitates 1-2 seconds when trying to quickly accelerate and then lurches forward alarmingly; cruise control is not functioning; waiting to have fuel mixture sensor replaced. I was not informed of first 2 recalls until I my engine overheated. I did get the rust recall and a sticker on my sliding door informing user of danger of having middle windows open while opening the middle door could catch a head or other extremity. Toyota dealer service manager says mine is the only 04 sienna experiencing any problems except for the recalls on the radiator; the steering hose; the rust tape; and the middle seat belt. Not so according to all I have read here. Most of the problems have occurred between 22,000 and 34,000 miles; the dvd screen always failed to lock into a good position for the middle row viewers.

Filed Mar 25, 2005 · Acceleration · 24,000 miles · IN

Cruise control will not work manually if the laser system is not functioning . Laser system cruise control is broke. You can not turn on the manual cruise control unless you stop the van and turn it off and set the control to noral. The laser was broke from car wash or road haz.ard.