NHTSA — Vehicle Speed Control Problems

CarComplaints.com Seal Of Pretty Good

2.3

hardly worth mentioning
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
68,835 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2003 Mazda MAZDA6 engine problems

engine problem

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2003 Mazda MAZDA6 Owner Comments

problem #18

Aug 022020

MAZDA6

  • 159,185 miles

A D V E R T I S E M E N T S

When I take my foot off the gas it stays at the same speed or it speeds up on its own. When I press on the break sometimes it feels like it's not going to stop and just keep going or it jerks forward when I stop. This happens when I am driving on the road and the cruise control is not on when this happens.

- Fort Wayne, IN, USA

problem #17

Aug 212017

MAZDA6

  • miles
2003 Mazda6 model cars were built with faulty throttle bodies. Unaware of this, I bought one of these vehicles and immediately began experiencing issues with it. When driving very slowly, under 15 mph, the car will suddenly throttle, accelerating it in bursts even when applying the brakes. That issue is problematic but relatively minor; however, there is a much more dangerous issue the faulty throttle body creates. When driving at any speed, the faulty throttle body can cause the engine to cut out without warning. My wife was driving with our kids in the car the first time we had the engine cut out while driving (soon after purchasing the car). Luckily, she was driving in a residential area at 25 mph. The engine has cut out on me while driving 65 mph on the freeway. I was forced to coast through freeway traffic to the shoulder in order to stop the car and restart the engine. The engine has cut out, without warning, at several speeds. There is no rhyme to when it will cut out and no indication it's going to cut out ahead of time. I spent over $500 trying to solve the problem with mechanics unsure what was wrong. Then a mechanic happened to have an old service bulletin (sb), dated 5/18/2006, from Mazda that stated throttle bodies with the markings aa, ab, or ba at the end of their serial numbers (as is the case with the one in my car) are "no good". because the part is labeled "no good" under Mazda letterhead, I figured there must have been a recall issued before I owned the car that the previous owner somehow missed. I took the car in to a Mazda dealership where I was assured no recall has ever been issued on the part and in order to replace it, the cost will be over $1,000. A recall must be made on this extremely dangerous and faulty, by Mazda's own admission, part before unsuspecting people are injured or killed, if that hasn't happened already.

- Sunnyvale, CA, USA

problem #16

Sep 092014

MAZDA6

  • miles
My vehicle has been having an issue with the throttle position sensor. As well as the PCM, usually connected as noted by my mechanic. 3 things can come from this he said. I could be having an issue with the gas pedal, the computer, or I need a new throttle body. From my understanding so far the issue causes the computer to incorrectly read, causing the check engine light as well as a few others to abruptly turn on while car is in full motion, for me this is typically at 55 mph. The car then looses the ability to properly accelerate, or decelerate. I have to quickly pull my car to the shoulder, put in park while the car seems to be lurching forward, and turn off the engine. If I do not do this quick enough the engine begins to rev high and low continuously. My RPM gauge bounces around as it is doing so. After leaving the car off for a few moments I can then restart. My check engine light will now stay on for about 50 miles and turn itself off. Once the light has gone off usually within 15 miles my car will do it all over again. After calling my dealer, because I still owe 2 more years of payment on the car, I am told that they can fix it if I have my warranty intact. Unfortunately it has run out as of July. The part alone from the dealership is $700. Why is there no recall on this issue if so many people are having it?

- Georgetown, DE, USA

problem #15

May 022014

MAZDA6 4-cyl

  • 107,000 miles

A D V E R T I S E M E N T S

Was at a stop sign to make a left turn half way thru the car stalled and all lights came on, vehicle behind me almost ran into us. Barely got pulled over to the side of the road had to turn car off and then back on the check engine light remained on but vehicle would drive, after about 5 starts the light came off had the car checked, was told it was the throttle body. One week later same thing wet to pull onto a busy street and car stalled almost causing another wreck, tried to drive it home and stopped at the grocery store, when I went to pull in the car stalled again in the middle of the street, blocking on coming traffic. Called Mazda to see how much it would cost to be fixed, the lady told me that if it was still under warranty it would be free but that expired in 2011. I have seen many of the same complaints about this, Mazda has admitted to it being a problem but has not recalled it. We have two kids and thank god nothing serious has happened with us in the car. This problem could very easily cause injury or deaths to any drivers on the road.

- Portland, OR, USA

problem #14

Jul 272012

MAZDA6

  • 155,000 miles
While driving home the car seemed to have lost all power, but was still running. I was able to coast to my house but then tried to stop and the car surged. I had to pull the emergency brake to stop. I was quite shaken at that point. The engine light came on. I was able to drive it back to town to have the car checked, no error codes showed up on the computer. The engine light did go off, the car ran fine for about 3 months then proceeded to do the same thing. The car lost power but I was able to coast to my place of work. However even though there seemed to be no power again when I tried to brake the car surged and the car almost jumped the curb, which would have put me in my office. I again had the vehicle checked, no errors. After researching it seems this may be due to the automatic throttle sensor. Question with all the complaints, cars stalling at high speeds and the surging of vehicles why is there no recall. You recall for a stupid lights, over spraying of a clear coat, but no recall on something that is putting people in danger?? I don't understand.

- Frenchtown, MT, USA

problem #13

Aug 152012

MAZDA6

  • 110,000 miles
I was driving on the interstate in ga going a little over 70mph in the fast lane and all of a sudden it kicked in to limp mode to about 10mph. I almost had a semi rear end me but was lucky enough to get out of the way just in time. I could turn the car off and it would reset it for awhile and then do it again. Then it finally got to the point it was doing it way too much. It turned out to be the throttle body. I learned that they know about it but wont recall it. Its been sitting for a year because they want $900 to fix it. I feel like I should drive it and let somebody hit me just to make it a recall so all the 1000S if not 10 of thousands of people who have the same problem will be able to get it fixed. Clearly that is a huge safety issue and should be a recall.

- Maysville, KY, USA

problem #12

Oct 092011

MAZDA6

  • 148,000 miles

A D V E R T I S E M E N T S

Traveling at speeds of 30-60 mph during any type of traffic (stop and go, freeway speeds, etc), my 2003 Mazda6 will suddenly go into a "safe or limp" mode characterized by abrupt loss of power with no ability to accelerate. The rpms drop to between 1000 and 1300 and fluctuate quickly between the two numbers. I have had to quickly press the clutch, turn the car off and back on to regain normal function. When taken to a mechanic, the root cause was determined to be a defective throttle body. Upon more research (including this site), this does not appear to be an uncommon issue for this model of Mazda.

- St. Paul, MN, USA

problem #11

Aug 012011

MAZDA6 6-cyl

  • 125,000 miles
The vehicle acceleration cuts off and the dash board lights are all on. You will have to shut off the car and turn it back on before it will work correctly. Dealer said their diagnostic did not show any throttle sensor errors but my scan tool did.

- Edwardsville, KS, USA

problem #10

Sep 042011

MAZDA6 4-cyl

  • 70,200 miles
Car experienced unintended acceleration in stop-and-go traffic (0-30 mph) on 9/4/11 and 9/7/11. Tachometer needle was bouncing between 1 and 3. car accelerated, and rpms increased, while on a level surface, without the gas pedal applied. Car fought against my efforts to slow down by breaking. Car stabilized upon reaching 40 mph. On 9/7/11, the Mazda dealership attempted to correct the problem by cleaning the throttle body, but the intervention failed to correct the problem and it recurred on 9/7. this is a serious complaint with a high risk of injuries or death. Mazda owner internet message boards describe this problem repeatedly. Please investigate and mandate that Mazda identify an immediate correction to this dangerous problem.

- Douglaston, NY, USA

problem #9

Jul 112010

MAZDA6

  • 98,000 miles
Traveling at freeway speeds in ca on the san francisco bay bridge during evening traffic, my 2003 Mazda6 suddenly went into "safe or limp" mode. This caused abrupt loss of power with no ability to accelerate, which almost caused a multi vehicle accident. When taken to a mechanic, the root cause was a code dtc P2135 for a defective throttle body. Mazda admits 3 (three) versions of their throttle body for that vehicle defective with automatic discard if there is a mil with dtc P2135(per technical service bulletin no. 01-016/06 issued 05/18/2006 by Mazda North american operations), and throttle body markings "aa","ab","ba". mine is an "aa". obviously Mazda admits that these are defective, but only replaced them under warranty and my vehicle is not under warranty any longer. They call the new part an "upgraded version". my vehicle has done this (safe mode) several times, so now it is parked until I can get it fixed (quoted price for repair is $714 from Mazda dealer). These incidents creates an extremely dangerous situation and I feel very lucky that I was not involved in an accident when this happened to me, and luckily no one was injured, it could have been a very dangerous situation. I feel Mazda has made a technical service bulletin admitting that this part is defective and it can cause danger and possibly loss of life. Mazda needs to be forced to make a recall and replace these parts at no cost to the consumer. Defective part - throttle body with markings "aa", "ab", "ba" mine is "aa"

- Medford, OR, USA

problem #8

Apr 042010

MAZDA6

  • miles

A D V E R T I S E M E N T S

Over a period of 1-1/2 hours, our 2003 Mazda 6 quickly lost all acceleration power on 5 different occasions while driving out of town on the highway. Following a 'slight bump' the car went from 70 mph to 35 mph to 10 mph, quickly, regardless of pressure applied to the accelerator. Getting to the side of the road in traffic going 70mph+ was in itself a challenge and after pulling to a complete stop the car began jerking fiercely. Only turning off the engine completely was the system 'reset'. the Mazda dealership hooked it up and determined the throttle body must be replaced for a quoted cost of $534.41 (macon, ga). The sensor itself, the likely culprit for this issue, is not offered or available for sale by Mazda without its 'body', unlike countless other makes, which is outrageous, but the most disgusting part of this issue is that although there are a critical number of complaints logged about this issue, the tps has not been listed as a recall. The dealership stated they did not have to replace it since there were only 'service bulletins' listed and no actual recalls for the parts. They are very aware of the situation. From my own experience and my daughter's with this issue, I can guarantee that this has definitely caused serious injuries, if not fatalities, that just haven't been reported or possibly identified. I will continue to hunt down the sensor as I will not fall prey to Mazda's 'racket'. the car will sit until I locate the part, or end up being parted out.

- Warner Robins, GA, USA

problem #7

Aug 052009

MAZDA6

  • 71,000 miles
While driving home from my chardon, oh office on either Aug 5 or 6, 2009 at 35 mph my car's RPM needle started jumping and the car's "gas pressure" felt like it was hicupping. The RPM needle jumped from @2 to 4 twice, then the car started steadily accelerating in speed. The brake pedal at this time felt "hard" and the car was "fighting against my attempt to slow down" and the RPM's were still trying to accelerate. I imagine if I pushed on the brake and the gas pedal at the same time, it would simulate the way it felt. I also have a manual shift mode on my car and used it to more effectively slow down (vs using the brake) but at the same time the car was still trying to accelerate, but couldn't because I was in a lower gear/manual mode. And I remember while in manual gear 1, my car was lurching me back and forth in my seat as I drove through my neighborhood to get home, and my foot was off the gas pedal! on Aug 12th, 2009 I mentioned this event to a Mitsubishi dealer's mechanic (friend of my father) who was replacing my power steering line, he took a look at my car but said it seemed fine. My husband has been driving that car since that event, because I am afraid of it happening again. The car has not done this while my husband has been driving it. Not to sound like an oddball, but if I didn't know better I would have said my car was acting possessed, like the movie "christine". I have to think that there is some correlation to what my car did and what is going on with Toyota. My husband is an electrical engineer and he used to work for grob systems, who does engineering for multiple automobile manufacturers, and I wonder if Mazda has some same system in their automobile's as Toyota and if it was engineered by the same supplier. I would swear on a bible that this happened to me with my car. (my husband left grob to move to cleveland and marry me). It sucks having this car now, it is paid off, I'm afraid to drive it, and I don't want to sell to an innocent stranger.

- Painesville, OH, USA

problem #6

Aug 232008

MAZDA6

  • Automatic transmission
  • 81,000 miles
The contact owns a 2003 Mazda 6. while driving approximately 20 mph, the contact applied pressure to the brake pedal several times before the vehicle slowed down. The vehicle accelerated without the accelerator pedal being depressed. There were no warning indicators illuminated on the instrument panel. The vehicle was taken to an independent mechanic and it was concluded that the failure was related to a defective throttle; however, the vehicle began operating normally after the diagnosis. The technician recommended that the vehicle be taken to an authorized dealer. The VIN was unknown. The failure and current mileages were 81,000. Updated 10/16/08.

- Kingman, AZ, USA

problem #5

Jul 202006

MAZDA6 4-cyl

  • Automatic transmission
  • 77,000 miles
: the contact stated that the vehicle accelerated on its own and on many occasions while driving 55 mph. This occurred even while applying the brakes. On one occasion, the vehicle almost hit a pedestrian. On another occasion, the vehicle ran through a red light. The vehicle was taken to the dealers who determined the problem was pertaining to the throttle body. The vehicle was repair however the problem persists.

- Milford, NJ, USA

problem #4

Jun 032005

MAZDA6 4-cyl

  • Manual transmission
  • 21,350 miles
: the contact stated there were several problems with the vehicle. The first problem involved the brake pads that were worn out and had to be replaced after 20,000 miles. The second problem dealt with manual transmission. Sometimes the manual transmission shifted roughly. Third problem, in cold weather, the engine surged and revved high for three seconds. The dealership told the contact the brake wear was normal. The dealership could not duplicate the other problems.

- Toledo, OH, USA

problem #3

Nov 092004

MAZDA6 4-cyl

  • Automatic transmission
  • 16,000 miles
While driving 40 mph vehicle intermittently accelerated at higher speed. Cruise control would not be engaged during this issue. Vehicle was taken to the dealer on several occasions, and they were unable to duplicate the problem. The vehicle was taken to the dealer and was told that the vehcile was in good condtion and that nothing was wrong. The vehicle would also hesitate at various speeds and made a clunking noise. The vehicle revved high while at a complete stop. The check enigine light illuminated intermittently. Each time the dealer turn the engine light out it would come back on.

- Mastic Beach, NY, USA

problem #2

Oct 012003

MAZDA6 4-cyl

  • Automatic transmission
  • 300 miles
I purchased my 2003 Mazda 6S in October 2003. Since I have owned the car I gets poor gas mileage on it (about 16-18 miles per gallon). I do plenty of city driving but I still feel that this is not adequate. Even when I drive on the highway the gas mileage averages poorly. There is also a smell coming from the exhaust when vehicle is in motion. The vehicle also rev's up higher before switching from lower gears to higher gears. I do not 'jack rabbit' start or stop the vehicle. There is also alot of brake dust on the rims of the front wheels. Acceleration is very poor. There is also a jerk when the vehicle switches from first gear to second. Don't get me wrong I love the way the vehicle looks, which is the main reason why I bought the vehicle, but the overall quality has turned out to be much poorer than I had expected.

- Elkhart, IN, USA

problem #1

Jun 202003

MAZDA6 4-cyl

  • Automatic transmission
  • miles
Was left stranded when check engine light and at light came on. Car would not accelerate above 20 mph and had some jerking. Had car towed in. Service dept replaced throttle body and sensor. Car still repeatedly has a jerk/hesitation when holding steady between the speeds of 40mph and 50mph. Have brought the car in three times for the jerking/hesitation and the service mechanic does not know what else to do. They tried redownloading the computer which worked for about 1 week and then the jerking/hesitation proceeded. My service dept has spoken to customer service of California and they say they have not heard of any of these problems with any other Mazda 6's and they have no idea what it is. I have also experienced a water leak in my vehicle about a month after I bought it which flooded my whole passenger side. Carpet had to be replaced. My brakes have a squeaky, grinding noise when turning. My back seat seams are coming unsewed. Will have to get the fabric replaced. My question is, "what's next?" I have already recieved legal advice and my lawyer thinks I have a pretty good case. If nothing can be done, then why not replace the vehicle. I am fed up with spending my time at the Mazda dealership. I bought a new vechicle to stay away from mechanical difficulities.

- Marksville, LA, USA

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