Smart Car of America Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
I'm new to the forum having recently purchased a 2009 Fortwo Passion with 86,000 miles on it. I have only had it 3 weeks and 500 miles. It has run perfectly until yesterday (Even with the stupid transmission). Yesterday, running it in the automatic mode, as it was shifting through the gears it went from 4th to 5th as normal. Then it down shifted to 4th gear. After a few seconds it shifted back to 5th, then down to 4th. It kept doing this until I pulled the shift lever into the manual position. It ran like normal when using the paddle shifter and 4th and 5th gears worked great. Today I disconnected the battery, reconnected the battery, started the motor and let the computer reset everything. I just finished driving it in automatic mode and it is doing the same thing, shifting back and forth between 4th & 5th gears. I could use a little help from anyone. The nearest Smart Car dealer is in St. Louis and I am 180 miles south of there.
 

·
Premium Member
Joined
·
2,297 Posts
I'm new to the forum having recently purchased a 2009 Fortwo Passion with 86,000 miles on it. I have only had it 3 weeks and 500 miles. It has run perfectly until yesterday (Even with the stupid transmission). Yesterday, running it in the automatic mode, as it was shifting through the gears it went from 4th to 5th as normal. Then it down shifted to 4th gear. After a few seconds it shifted back to 5th, then down to 4th. It kept doing this until I pulled the shift lever into the manual position. It ran like normal when using the paddle shifter and 4th and 5th gears worked great. Today I disconnected the battery, reconnected the battery, started the motor and let the computer reset everything. I just finished driving it in automatic mode and it is doing the same thing, shifting back and forth between 4th & 5th gears. I could use a little help from anyone. The nearest Smart Car dealer is in St. Louis and I am 180 miles south of there.
Welcome to SCOA. :nerd: I have a couple questions and comments.

A.) It is NOT a stupid transmission, by ANY stretch of the imagination. It is a MISUNDERSTOOD transmission. But it is far from stupid.

B.) Are you having any concerns with engine performance? Is it lacking power? Is it in need of a tune-up? Is it throwing any check engine lights?

C.) Are you using premium fuel?

D.) Are there specific scenarios that trigger the car to shift between 4th and 5th, such as climbing hills?

E.) Have you read the transmission techniques section of your owners manual (likely pages 81 to 86)?

More throttle pressure = downshifts
Less throttle pressure = upshifts
Constant pressure, confident pressure, steady pressure is going to make the car more likely to stay in 4th.
Less pressure, lack of confident pressure, wobbly pressure, is going to make the car more likely to move to 5th gear, then back to 4th (more pressure), then back to 5th (less pressure), then back to 4th (more pressure), then back to 5th (less pressure), then back to 4th (more pressure), then back to 5th (less pressure), etc,.

Your only excuse is if the engine is having trouble developing power. But in manual mode (paddles and the shift lever), you are telling us that the transmission works fine.

So the "trouble" with this car is beginning to sound like the driver. So my true advice to you is my paragraph about shifting technique, reading pages 81 to 86 in your owners manual to study up on the transmission design, and to put down those car critic magazines and learn the proper shifting technique. And please stop blaming a perfectly fine transmission for your issues with the 1.0L 3 cylinder car. I mean this kindly. :nerd:
 

·
Registered
Joined
·
12 Posts
Discussion Starter #4
Sorry for calling the transmission "stupid". Maybe "unique" would be better. About the shifting, the shifting between 4-5 and 5-4 happens with constant accelerator pressure. The rpms change with the gears, but the accelerator is constant. I first thought that the bearing could be two tight which placed a load on the engine, but the car seems to roll freely.
I picked up the car from my mechanic right before the problem started. He replaced both front wheel bearings. The car accelerates like normal, so I don't think there is any problem with the new bearings. I can't think of anything that the mechanic could have done while replacing the bearings that could affect the shifting.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #5
The upshifting and downshifting still occurs when I have constant pressure on the accelerator. I am not speeding up or down, just holding my foot steady. there are no error lights or messages. Everything seems to work fine except the shifting. I don't hot rod the car, I just drive normally for an 68 year old. I use 93 octane gasoline. The transmission has shifted normally for the 3 weeks, 500 miles I have had the car.

The problem started right after I picked my car up from my mechanic. He replace both front wheel bearings for me. The right front was starting to make a slight whirling noise. The only thing I can think of would be if the new bearings were somehow binding and were putting additional load on the engine. I don't think this is the problem, but I am going to check it tomorrow. I can't think of anything else that the mechanic could have done which would have caused this problem.
 

·
Premium Member
Joined
·
2,297 Posts
Can't be the bearings causing this. If you had mentioned that the mechanic performed a tuneup, perhaps the ignition is weaker than usual, but sounds to me like it wasn't touched.

When you are in manual mode, do you believe the car is developing full power?

Even with steady throttle, you might need to adapt and go with stronger but still steady throttle pressure. If the engine is lugging, the computer will downshift for you. If you then go light with the throttle, it interprets that action as necessitating an upshift. Your foot/throttle pressure is your communication to the transmission control computer.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #7
In manual it seems to be developing full power. I have tried accelerating after it shifts into 5th but the problem is still there. In automatic transmissions when you accelerate (kick down) on the gas pedal the transmission downshifts to the next lower gear. Is there anything in the smart car transmission which can do the same thing. It seems like there is some kind of mechanism malfunctioning which upshifts and downshifts 4-5 regardless of anything you do.
thanks for all your replys
Gene
 

·
Premium Member
Joined
·
2,297 Posts
In manual it seems to be developing full power. I have tried accelerating after it shifts into 5th but the problem is still there. In automatic transmissions when you accelerate (kick down) on the gas pedal the transmission downshifts to the next lower gear. Is there anything in the smart car transmission which can do the same thing. It seems like there is some kind of mechanism malfunctioning which upshifts and downshifts 4-5 regardless of anything you do.
thanks for all your replys
Gene
If you're truly using the "kickdown" feature, that means you are flooring the gas pedal until you feel the click of the button underneath it, known as the "kickdown switch." Otherwise, if you are giving some gas and it is kicking down try giving a little bit less gas and see if it does the same. You might have a car that is kicking down because your engine is not developing full power, or you might be kicking down because you have an overly aggressive foot that is so strong you don't realize it until you engaged the kickdown and them aim to back off. Are you driving the car with really big, thick shoes? They might be numbing your ability to feel the difference between bullying the gas pedal and feathering it.

Or, your engine might not be developing full power and you're due for an engine tuneup. Lack of power will cause the trans computer to force downshifts more often.
 

·
Registered
Joined
·
1,635 Posts
Whether there is a problem depends on when the condition occurs. For example, if you are going at a steady speed at 40-45 mph and the road starts uphill slightly the car will shift down so as to prevent lugging the engine in a gear that is too high for the road speed. When the road levels out or start a down incline the trans will shift back up to 5th gear. If you go slower the trans may stay in 4th gear and going faster it may stay in 5th gear. If that is what is occurring I would suggest you vary your speeds to see what effect that has on the condition. I suspect there is not really a problem with the car.
 

·
Registered
Joined
·
1,018 Posts
Oil viscosity, tire pressure..

Mine did this.

I suspect either tire pressure, or oil viscosity...

Add 3-5 psi to your tires, above what the door sticker says.
I think it's 29 front, 31 rear, not sure...
I put 35 in, max is 44 on most tires, look on the side of the tire.

I think diesel motor oil, 5W-40, was used, instead of euro oil, 0W-40...
Change oil and filter with Castrol Edge, black bottle...
https://www.walmart.com/ip/Castrol-Edge-Strength-for-Maximum-Protection-0W40-Motor-Oil-5-Quart/35931146
 

·
Registered
Joined
·
12 Posts
Discussion Starter #11
I halfway solved the problem. The new bearings are pretty tight. I can disconnect the caliper so the pads don't press against the rotor, and spin the wheel about 1/2 turn. They turn smoothly, just pretty tight. The car is driving fine in manual mode. I just hope after I get a few hundred miles on the new bearings that they will loosen up a bit so I can eventually use the automatic mode.Thanks for all the help. Mike T said that I was in the wrong forum (for the 450) Is the 451 on this same site, or do I need to look elsewhere. Anyway, thanks again and I will probably continue to follow you guys in the future.
Gene
 
1 - 12 of 12 Posts
Top