This may have already been covered, but I wasn't able to locate a collection of features the smart 451 has that may not be obvious to most new owners. Many of these I have learned here, some I discovered by accident. I'll just jump into this and start a list. If this appears useful, please add to it and maybe a moderator will make it a sticky or FAQ or whatever.
1. If you remove either of the seats and start the car while the airbag is unplugged you will activate the Airbag warning light. This can only be reset by the dealer. Disconnect the battery if you need to remove a seat and don't forget to connect the wires under the seat before you hook the battery back up.
2. If you tap the turn signal (like for a lane change) it will flash 3 times before it stops, if you turn it all the way on and then off it stops immediately.
3. The emergency flashers are easy to punch on in the center of the dash. In bright daylight it is not so easy to see that the button is flashing, but both of the turn signals on the dash will catch your attention. Stop panicking and push the button in the middle of the dash.
4. In a panic stop the flasher will turn themselves on. (forestacademy)
5. In an accident the flashers will turn themselves on. (forestacademy)
6. If you have the Auto-wipers on, and it's raining, putting the car in reverse will make the rear window wiper come on.
7. Since I first owned the car I have only used the hatch button on the remote to open the hatch. Then one day while standing behind the car waiting for the remote to open the hatch I realized that if I had hit the unlock button twice, I could already have opened the hatch. Then I realized the same thing when I'm sitting in the car, instead of fumbling for the key fob and holding the hatch button, I can just hit the unlock button on the dash. Probably just my OCD, but seemed like a revelation to me ;-). (hopefully clearer)
8. Traction control works by reducing power, which explains the need of a few people to disable it to climb long snowy driveways. In the past I've had cars that used limited slip or locking differentials to distribute the power to both axles, and more recently a car that would use the brakes to slow the spinning wheel and direct power to the wheel with traction. The smart does not work like any of these. Doughnuts in the snow are possible, but disappointing. I recently was trying to inspect a bent rim that had been repaired, with the car on jack stands I put it in gear, the rear wheels started spinning and I could clearly see the rim was still bent. Applying the accelerator caused the engine to sound like it was shutting down, it kept running, but the rpms were lower than with no input.
9. (Please do not do this, this could be dangerous and disables the safety features designed to allow the incompetent to drive in a semi-safe fashion.)
To disable traction control, ABS, and have fun in the snow, hold both buttons on either side of the speedo, turn key on, wait a few seconds and the yellow triangle/brakes and ABS will light up. Shutting car off and restarting will return to normal... (jetfuel)
Using 2 fastfood straws held in one hand, spread into a V will hold the buttons while you turn the key (Red-Devil)
10. Paddle shifters are easy to accidentally engage (especially when you first start driving a smart) so if the rpms start climbing and you feel like it should be shifting, check the gear indicator in the dash, you probably just need to put it back in automatic mode.
11. To get the smoothest shifting out of the smart, push the accelerator down to get the car moving then slide your foot over to the carpet (right side in the US) and lock your foot in position. The car will automatically cut the accelerator between gears and resume when shifting is done. You can develop your own variations as you get used to it, but this seems to work the best out of the box. Drivers used to manual trans cars will instinctively want to modulate the accelerator which can cause the "bucking bronco" shift.
12. When the trans is in manual, pull the right paddle shifter and hold it for a while it goes to automatic without using the floorshifter. (rexio and chieftmc)
Or move the floor shifter towards you and back away from you.
13. If you pull up on the e-brake one click or less, it engages the throwout bearing, like holding the clutch in on a manual. (smart-1 and chieftmc)
14. TPMS light tells you when the tire pressure varies from what the tires had in them when the system was last reset. Make sure the tires are inflated correctly then hold the button until the light resets.
15. If your salesman gives you an answer that seems odd, ask here, we know more about these cars than they do!
16. There is a secret shelf, it's forward of the passenger side footrest next to the firewall. (smart-1)
Caution, not chocolate friendly (or anything easily melted) (jimvw57)
17. The passenger seat slide adjuster makes an excellent large cup holder (forestacademy)
18. You don't need a security system for the remote locks to works.
19. Ignition key does not spin the starter immediately the first time you try to start the car. You need to hold it for a few seconds. This does not happen when the engine is shut off, then restarted.
Additional explanation provided by (dennyrex)
I think this delay is the system booting, if you turn the key, but not to the start position for a second or two, and let the thing boot (all the system lights on the dash, etc.), it will engage the starter as expected when you turn it the rest of the way. and remember, no foot required, everything computer controlled.
20. Once the starter engages you can release the key, it will spin until the engine starts.
21. You can lock your keys in the car! If your doors are locked while the rear hatch is open, you can leave your keys in the car and close up the hatch. You have now managed to lock your keys in the car! (wrumbarger)
22. If you use the remote to unlock your smart and do not open the doors, after a bit, the locks will re-lock themselves. (jimvw57)
23. If you press the Central Locking Switch on the dash while the drivers door is open, and the key is in the 1 position, then removing the key and closing the door will leave the car locked and the optional factory alarm armed.
This is the only way to lock and arm the factory alarm with only a single acknowledgment beep.(sironian)
24. With the ignition off, you can still press the radio on button and get the radio to play for around an hour. It shuts itself off after that. (jimvw57)
25. If you burn an MP3 CD for the Smart Radio 10, you can put lots of songs on the CD, BUT it only will play the first 255 songs. For those into computers and binary, it sounds like an 8 bit limit to me. (BobDiaz)
26. Revelation...the use of a hair dryer (turbo) will kill your MPG... (jetfuel)
27. There is a way to enter your car when the remote battery is dead or the vehicles battery is dead. A plastic circle with the "key" icon just below the driver external door handle is a cover for manual unlock feature. However this has been a problem for several owners and it is recommended that you try it out in a non-emergency environment. First, remove the plastic plug, there should be a tab going into the lock almost as long as the circle's diameter (this may have broken off in the lock preventing the key from being inserted.), then insert your key and turn, this should unlock the driver's door. If not, go see your dealer.
Well that should work as a starter. As I mentioned in the beginning, I don't claim any of these as "my discoveries", just things I wish I knew when I first bought the car (from the dealer who said the remote locks would not work on my car because it didn't have a security system, and said to "fix" the TPMS light, just hold the button until it clears (never mind checking the tire pressure ;-))). These are based on my experience with a 2009 Passion and 16 months of driving it.
If there is already a list, sorry. If you like this, add to it, I'll edit the original post to add new entries to the list.
1. If you remove either of the seats and start the car while the airbag is unplugged you will activate the Airbag warning light. This can only be reset by the dealer. Disconnect the battery if you need to remove a seat and don't forget to connect the wires under the seat before you hook the battery back up.
2. If you tap the turn signal (like for a lane change) it will flash 3 times before it stops, if you turn it all the way on and then off it stops immediately.
3. The emergency flashers are easy to punch on in the center of the dash. In bright daylight it is not so easy to see that the button is flashing, but both of the turn signals on the dash will catch your attention. Stop panicking and push the button in the middle of the dash.
4. In a panic stop the flasher will turn themselves on. (forestacademy)
5. In an accident the flashers will turn themselves on. (forestacademy)
6. If you have the Auto-wipers on, and it's raining, putting the car in reverse will make the rear window wiper come on.
7. Since I first owned the car I have only used the hatch button on the remote to open the hatch. Then one day while standing behind the car waiting for the remote to open the hatch I realized that if I had hit the unlock button twice, I could already have opened the hatch. Then I realized the same thing when I'm sitting in the car, instead of fumbling for the key fob and holding the hatch button, I can just hit the unlock button on the dash. Probably just my OCD, but seemed like a revelation to me ;-). (hopefully clearer)
8. Traction control works by reducing power, which explains the need of a few people to disable it to climb long snowy driveways. In the past I've had cars that used limited slip or locking differentials to distribute the power to both axles, and more recently a car that would use the brakes to slow the spinning wheel and direct power to the wheel with traction. The smart does not work like any of these. Doughnuts in the snow are possible, but disappointing. I recently was trying to inspect a bent rim that had been repaired, with the car on jack stands I put it in gear, the rear wheels started spinning and I could clearly see the rim was still bent. Applying the accelerator caused the engine to sound like it was shutting down, it kept running, but the rpms were lower than with no input.
9. (Please do not do this, this could be dangerous and disables the safety features designed to allow the incompetent to drive in a semi-safe fashion.)
To disable traction control, ABS, and have fun in the snow, hold both buttons on either side of the speedo, turn key on, wait a few seconds and the yellow triangle/brakes and ABS will light up. Shutting car off and restarting will return to normal... (jetfuel)
Using 2 fastfood straws held in one hand, spread into a V will hold the buttons while you turn the key (Red-Devil)
10. Paddle shifters are easy to accidentally engage (especially when you first start driving a smart) so if the rpms start climbing and you feel like it should be shifting, check the gear indicator in the dash, you probably just need to put it back in automatic mode.
11. To get the smoothest shifting out of the smart, push the accelerator down to get the car moving then slide your foot over to the carpet (right side in the US) and lock your foot in position. The car will automatically cut the accelerator between gears and resume when shifting is done. You can develop your own variations as you get used to it, but this seems to work the best out of the box. Drivers used to manual trans cars will instinctively want to modulate the accelerator which can cause the "bucking bronco" shift.
12. When the trans is in manual, pull the right paddle shifter and hold it for a while it goes to automatic without using the floorshifter. (rexio and chieftmc)
Or move the floor shifter towards you and back away from you.
13. If you pull up on the e-brake one click or less, it engages the throwout bearing, like holding the clutch in on a manual. (smart-1 and chieftmc)
14. TPMS light tells you when the tire pressure varies from what the tires had in them when the system was last reset. Make sure the tires are inflated correctly then hold the button until the light resets.
15. If your salesman gives you an answer that seems odd, ask here, we know more about these cars than they do!
16. There is a secret shelf, it's forward of the passenger side footrest next to the firewall. (smart-1)
Caution, not chocolate friendly (or anything easily melted) (jimvw57)
17. The passenger seat slide adjuster makes an excellent large cup holder (forestacademy)
18. You don't need a security system for the remote locks to works.
19. Ignition key does not spin the starter immediately the first time you try to start the car. You need to hold it for a few seconds. This does not happen when the engine is shut off, then restarted.
Additional explanation provided by (dennyrex)
I think this delay is the system booting, if you turn the key, but not to the start position for a second or two, and let the thing boot (all the system lights on the dash, etc.), it will engage the starter as expected when you turn it the rest of the way. and remember, no foot required, everything computer controlled.
20. Once the starter engages you can release the key, it will spin until the engine starts.
21. You can lock your keys in the car! If your doors are locked while the rear hatch is open, you can leave your keys in the car and close up the hatch. You have now managed to lock your keys in the car! (wrumbarger)
22. If you use the remote to unlock your smart and do not open the doors, after a bit, the locks will re-lock themselves. (jimvw57)
23. If you press the Central Locking Switch on the dash while the drivers door is open, and the key is in the 1 position, then removing the key and closing the door will leave the car locked and the optional factory alarm armed.
This is the only way to lock and arm the factory alarm with only a single acknowledgment beep.(sironian)
24. With the ignition off, you can still press the radio on button and get the radio to play for around an hour. It shuts itself off after that. (jimvw57)
25. If you burn an MP3 CD for the Smart Radio 10, you can put lots of songs on the CD, BUT it only will play the first 255 songs. For those into computers and binary, it sounds like an 8 bit limit to me. (BobDiaz)
26. Revelation...the use of a hair dryer (turbo) will kill your MPG... (jetfuel)
27. There is a way to enter your car when the remote battery is dead or the vehicles battery is dead. A plastic circle with the "key" icon just below the driver external door handle is a cover for manual unlock feature. However this has been a problem for several owners and it is recommended that you try it out in a non-emergency environment. First, remove the plastic plug, there should be a tab going into the lock almost as long as the circle's diameter (this may have broken off in the lock preventing the key from being inserted.), then insert your key and turn, this should unlock the driver's door. If not, go see your dealer.
Well that should work as a starter. As I mentioned in the beginning, I don't claim any of these as "my discoveries", just things I wish I knew when I first bought the car (from the dealer who said the remote locks would not work on my car because it didn't have a security system, and said to "fix" the TPMS light, just hold the button until it clears (never mind checking the tire pressure ;-))). These are based on my experience with a 2009 Passion and 16 months of driving it.
If there is already a list, sorry. If you like this, add to it, I'll edit the original post to add new entries to the list.