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On an episode of a popular television show, a man is showing off his new truck. While bragging about the interior, he accidentally hits the stick with his arm, and puts it in gear. Then, when he starts it remotely a little while afterwards, it roars forward and kills him. Is this possible? Could a vehicle actually behave in this manner?

  • many automatics don't allow the car to start when not in park or nuetral, something similar can be done for manuals – ratchet freak Oct 22 '11 at 1:34
  • My manual-shift car will not start unless you depress the clutch pedal. There is an interlock that disables the starter unless the clutch is all the way down, even if the transmission is in neutral. – Fake Name Oct 22 '11 at 11:06
  • Can we see the video? :) – Alex Oct 22 '11 at 14:53
  • It's not on Youtube, sorry. If you can find the episode "Trucked Up" of 1000 Ways to Die, that's it. – user4882 Oct 22 '11 at 16:04
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Yes, it is possible, but many modern Remote Start units have safety features that prevent this.

For an automatic transmission vehicle, the safety mechanism is simpler in that it only needs to check if the car is in Park. If it is not, it simply won't start the vehicle. In fact, most cars do no allow the starter to turn if the transmission is not in Park or the brake is not depressed.

For a manual, things get a little more complicated. I have installed two units similar to this(older model) in manual transmission vehicles. In the installation manual, you will see several additional components that need to be installed for a manual vehicle. The full installation manual is hard to come by online as it is usually shipped only to certified installers (Best Buy, Car Toys, etc). You can usually find these guides on car forums if you search hard enough.

Here is the owners manual. On page 31 under the header Manual Transmission Start (MTS mode) are instructions on how to use the remote start feature on a manual transmission vehicle. The short version is:

  1. Bring the vehicle to a stop with the engine running and foot still on brake
  2. Engage the hand brake
  3. Release the foot brake
  4. Within 20 seconds, press the remote start button on your remote
  5. Exit the vehicle
  6. Lock vehicle. This will also turn the vehicle off

The idea behind this is that if you can leave your vehicle while it is still running, then it will be safe when the car is remote started. If the car is ever opened (detected via door sensors), the parking brake is disengaged, brake is depressed, or in more advanced units, the transmission has been moved into gear after the remote start sequence has been performed (above), the remote start functionality will be deactivated until it is properly set up.

Now, I suppose it's possible to be a funny man and shift the car into gear after the process above has been complete; open window, not actually leaving the car, etc. The root of the answer then lies in the configuration of the remote start and the car itself.

With the units I have installed, you can configure the time the starter is engage in two different ways. These options will dictate how long the car will try to start for; how long the car will move for.

  1. Auto-Detect
  2. Time

Option 1 usually requires a wire to be connected to the car's tachometer. After installation, you must Learn the tach, meaning make the remote start unit recognize what the output of the tach wire is when the car is on. Using this method, the remote start will engage the starter until a similar tach reading is found. There is usually a top end time limit for this as well.

Option 2 is simple. You pick a length in time to have the starter engaged.

The starter is also an important component. As your car ages, your starter will not crank as well. The stronger your starter, the more force it can apply to the engine and thus the wheels (if transmission is engaged). It would be possible for a car to be started in gear, but not be strong enough to defeat the friction of the parking brake.

Thus, if you manage to bypass all the safety mechanisms and happen to have a strong starter, it is quite possible for a vehicle to "Come alive" and start rolling forward, though, the actual reaction would be more accurately described as jumping forward. In fact, I used to work at a mall where someone accidentally activated their remote starter (not properly installed). Their car ended up in a dental office.

P.S. Someone mentioned that the clutch need to be engaged to start a manual transmission. This is not the case if viper alarms (sort of). There is a wire that becomes active when the remote start is activated. This wire is connected to a relay which connects to the wires behind the clutch pedal. When the remote start is activated, this setup simulates the clutch pedal being pressed, allowing the car to be started.

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Yes, A vehicle starter can move a standard shift vehicle across the parking lot even with an occupant standing on the brakes. I worked at a car manufacturer where we tried this by disabling the clutch and neutral safety switches. The engineer could not stop the vehicle from moving with the brakes, torque multiplication of the (starter/flywheel X trans gear X axle ratio) is very impressive!

Remote start isn't the only possibility. Most manufactures now crank the car until it starts, even if you let go of the key. You can often test yours (auto or manual) for "single turn start" by pushing (and holding) the accelerator to the floor and then hit the start and let go of the key (or the push button). As long as the pedal is held down, the fuel injectors are off to clear a flooded engine. When you let up on the pedal, the cranking engine will start. I usually do this "long crank" trick to freak out the salesman when I buy a new or used car.

Remember: Safety switches do fail even on a new car! Never start any car with someone in front or back of the car!

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    I'd like to see a reference for this -- common production cars cannot overpower the brakes, and while after first starting up there may not be much vacuum to assist power brakes, it seems unlikely that the car could make it across a parking lot without the driver being able to stop it by "standing on the brakes". – Johnny Apr 1 '14 at 20:56
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    Welcome to Skeptics! Please provide some references to support your claims. – Larian LeQuella Apr 2 '14 at 1:25
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Not if installed correctly. You could defeat the safety features and have this happen. I would be unlikely to "roar" forward, without depressing the accelerator pedal the engine would be at idle, some automobiles don't move at all at idle, some move but not quickly in my experience.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=571.102

  • Welcome to Skeptics! Please provide some references to support your claims. – Oddthinking Oct 22 '11 at 15:04
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    Note that the OP is talking about a car with a manual transmission... if in gear with the engine running, this will "roar" forward. – Flimzy Oct 23 '11 at 1:49
  • @Flimzy - or stall. – Fake Name Oct 23 '11 at 10:56
  • @FakeName: I first assumed a vehicle would only ever stall in these conditions, but in providing my own anwwer, I found several reported cases of vehicles lerching forward and causing serious property damage in these cases. However, the examples I found were apparently not sufficient for providing an answer here. – Flimzy Oct 23 '11 at 21:00
  • @Flimzy this is because the starter motor provides enough torque to move the vehicle (it has to to get the first compressions of the cycle going) before the engine will stall when it cuts off – ratchet freak Oct 24 '11 at 11:57

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