Smart Fortwo kicking out front end

[alanb8222]

Hey everyone I need some advice I have just had the two rear tyres changed on my smart car and is causing the car to now slide out when I am cornering at any speed and I am not braking either smart technicians are puzzled they said at first it was the tyres I have had put on I had toyo tr1s put on so they tried changing them and still have the same problem the steering in a straight line is very light and I am always having to compensate more than before can anyone help me with this has anybody ever had this problem ???🤔🤔

[Thrumbleux]

What sizes of tyres front and rear and before and after on rear?
How much tread is left on the front tyres?

[alanb8222]

Hi the rear tyres are 215 40 16
And that was the size the car came with
And the front wheels are 175 50 16 again the size the car came with with good tread on as well smart garage already tried changing front tyres with new grip but didn't make any difference ?

[Thrumbleux]

Mine (a 450 - yours?) understeered vehemently with smaller section front tyres than rears. Improved with 175s on the front and better still with 195/50-15s allround.
Hard to tell what is going on with yours though IMO you are overtyred at the rear and undertyred at the front. Might be worth checking the rear antiroll bar (assuming you have a 450) is as it should be.

[alanb8222]

This is my car the car was handling fine before I changed the tyres so it must be a sensor fault I reckon as it only slides out to the left when I am steering to the right and the ABS light is flashing on and off ?

[Thrumbleux]

and the ABS light is flashing on and off ?

If you had mentioned that earlier.....

Disconnect battery (or pull the MEG ECU fuse (#27?)) and then reconnect. Problem should vanish.
(Assuming 451 behaves as per 450).

[Mad smart person]

Greetings, other suspects, wheel alignment - hit a curb or pothole recently? Tyre pressure? Wheel bearings / suspension play? Brake pads? The ABS light is illuminating because the ABS system has been activated, IE it thinks one or more wheels are not turning as much as the others, which could be caused by, tyre pressure, tyre diameter, or a brake pad or shoe making contact with the disc or drum. Have a look at the hand brake cables, they may have been crushed or squashed. Get all four wheels off the ground, release the hand brake and see if the rear wheels turn freely. See if the front wheels turn freely as well. If they 'bind', that's possibly your problem.
Cheers, Ian.

[Thrumbleux]

The ABS light is illuminating because the ABS system has been activated,

OR the ESP - much more likely in this case and due simply to the ECU not recognising the new tyres larger rolling radius - exactly as happened on mine 10 years ago.

[alanb8222]

Hi they have tried re setting the ECU and it still was kicking out on the front end they are now saying it could be the front tyres I don't think by putting new tyres on the front is going to fix the problem could it be a faulty ABS sensor possibly what do you think Thrumbleux ? Ps thank you for all your input much appreciated 👍😃

[tolsen]

What the ECU has to do with it is beyond me.

[Buckster]

This may seem obvious but has someone over inflated the front tyres?

[Thrumbleux]

What the ECU has to do with it is beyond me.

See post #8. It happens, happened to me.

[Thrumbleux]

causing the car to now slide out when I am cornering at any speed 0;

Sudden breakaway? (as happens with a 450 if the outside front wheel encounters enough of a bump during hard cornering (when the spring runs out of travel)) or, power on understeer? (as happens on a 450 (and worse when the rear tyres are wider than the fronts)).

[tolsen]

See post #8. It happens, happened to me.

ECU does not control brakes.

[Thrumbleux]

ECU does not control brakes.

Something controls the ESP and disconnecting whatever that is from the battery resets it.