ESP problems

[Keith Knight]

Hi, SmartManiacs!
I am a newbie. I am sure there are already posts about ESP but i can't find them - coz I is stoopid!
I have a Smart 450 ForTwo Brabus 698cc turbo petrol 2003.
The Yellow ESP/ABS warning triangle flashes a lot when there is no obvious resaon for it to do so.
After it has flashed a few times - sometimes a dozen or so, the light stays on solid and acceleration is prevented. The car is brought to a halt. Stopping and starting the engine resets the ESP and the car drives for a bit longer before doing the whole thing again. Sometimes it will go for days without playing up. There is no obvious weather or road condition factor. All conditions seem fair game. Perhaps the only time this behaviour is reduced is when driving very slowly for short distances - paper shop, etc. The faster one drives the more likely it seems to happen. Bumpy roads may make it worse but not always. Of course we may be seeing a combination of "real" and "fake" ESP/ABS activations, just to confuse things.

I have checked the following:
1) ESP Control unit: no water ingress or corrosion, properly mounted and connected.
2) Reluctor rings: all sound and bright.
3) Wheel sensors: correclty aligned, tight and clean.
4) G-Force sensor: correctly mounted and connected.
5) Brakes: No leaks or much wear, fluid level ok and reservoir level sensor working.
6) Handbrake and warning light system ok.
7) Yaw sensor firmly mounted and connected.
8) "Trust" Plug utilised but light still stays on and engine still cuts out! (This is very strange, indeed!)
9) Star machine detects NO FAULT CODES

Yesterday, my wife was on the M4 in traffic, with roadworks and no hard shoulder. The orange light stayed on twice within a few minutes and brought the car to a halt - a very hairy experience. I consider the car now too dangerous to drive and the local Mercedes garage cannot find the fault.

Has anyone else had this or a similar problem? Have I missed something? I can have the ESP controller checked for about £55 and buy a new one for about £500 but if I do this as a last resort and it doesn't fix the problem, I shall have to disable the ESP system to be able to drive the car, which is inadvisable for very long.

Surely faulty sensors or controller should throw up some Star diagnostic scan codes?

HELP PLEASE!
Keith

[heinkeljb]

Re: ESP problems

Have you replaced any tyres recently?

Have you tried disconnecting the battery for a while? (Make sure you have the radio code).

First thought was reluctor rings. Have a another look at them, use a piece of chalk or scratch one so you know when you have been all the way round. You will need to take the wheel off to do the job properly.

John

[Keith Knight]

Re: ESP problems

John
Thanks very much indeed for replying.
Well ahead of you. Completely new set of original equipment tyres fitted IN THE MIDDLE of this problem - no change before or after. Exposed all reluctor rings and checked them thoroughly. No corrosion or splits or cracks. I even polished them!! They are perfect. Battery has been replaced IN MIDDLE OF PROBLEM - no change before or after.
(I always file radio codes away LOL). Have checked all earths, all fusebox connections, cleaned MAP sensor; Had a full service including full brake and steering check. New Master cylinder - no change before or after. No fluid leaks. Brake reservoir level sensor changed. I have physically exposed and checked every ABS/ESP component and any traction/stability related component in the entire car or watched while a mechanic has done it at the garage. They are completely stumped too!
The clutch does slip at high power and load but the Brabus does do that as it is quite powerful. You really have to put your foot down though and that is NOT when the problem specifically occurs. I have been running and studying cars for over 40 years and I CANNOT find this SOB!! If only the MB diagnostic machine returned an error code, we would have half a chance!! The only thing I can't easily check is whether the gearbox is causing excess drag/load but once again the diagnostic should have picked that up.
Any other ideas would be very welcome. For now, I think I am going to send the controller away to be electronically checked. There is a place in Bounrmouth that turns them around in 24hrs. Its just that as a retiree, I need to watch the pennies and even the check is about £55, without any repair/replacement. It could cost £500.
Thanks again very much for replying
Keith

[Mad smart person]

Re: ESP problems

Greetings, be fore you go spending big bickkies, have you had your shocks / suspension checked? The coil springs are known to crack. Another possibility is your wheel alignment, has that been checked lately? If not, take the car to someone that has a machine that can check/align all four wheels, not just the front ones.
Cheers, Ian.

[Keith Knight]

Re: ESP problems

Ian,
Thanks very much for responding.
I recently broke a front spring on Bridgend's famous potholes. I took a photo and got a witness and put in a claim for a new pair of front springs - which was met by BCBC. The ESP problem was the same before and after this event. I had the shocks and rear springs checked under my supervision at the same time. They are fine. Even though the shocks are ten years old, there is no bounce at all and no leaks. Of course the Brabus has short stiff suspension anyway and it would in my opinion, be virtually impossible to generate a fatal ESP/ABS cutout from any traction differential caused by such suspension. As I said in my original post, we are looking at a combination of "fake" and "real" activations. There are roads near me that I can drive down; some with reversing cambers and others with out of phase wave-like undulations where I can predict exactly where the ESP/ABS light will flash. These are "real" activations and have never resulted in a solid warning light and an engine cutout like the "fake" activations have. Only a traction differential equal to a missing reluctor ring tooth (1/42nd of a turn), a steering yaw, traction loss or severe G-force should result in an engine "kill". Each time the engine "kill" has occured the ESP system has happily reset, indicating a transient error. This is a contradiction of terms since a transient error should not stop the engine in the first place.
I have checked or had checked every component related to traction or stability and both myself and the local Mercedes garage are completely stumped. The fact that the engine still cuts out even with a "trust" plug installed should mean that the problem is internal to the ESP controller as the plug turns all the external sensors off. I would be more than happy to be wrong, if it means I can find a cheaper solution, though.
Thanks again for responding - keep thinking, please!!
Keith
ps. As for wheel alignment I have had this checked several times by the best equipment (due to potholes!) and although it has twice been out at the front and had caused "real" activations (repeated warning flashes), the "fake" behaviour was the same before and after in each case. Currently the alignment is spot-on.

[Evilution]

Re: ESP problems

"local Mercedes garage cannot find the fault"

This is not a surprise. They may have only looked in 1 place for error codes when in fact they could be stored in many places.

When you fit a trust plug, the /!\ light stays on. Engine cutting out could be a faulty/loose crankshaft rotation sensor or issues with the wiring to the clutch actuator. The wires chafe around the intercooler scoop so have a look there.

4) G-Force sensor: correctly mounted and connected.
7) Yaw sensor firmly mounted and connected.
Is this not the same thing? Under the carpet on the passenger side?
If this is giving false readings it could cause the ESP to kick in without giving errors, so could chaffed wires to the wheel rotation sensors.

A faulty brake light switch (faulty on the ESP controller side) can cause the power to be restricted to the engine.

Assuming you have checked the front reluctors too. I've not personally seen them go but it's good to check and clean up.

Remember, sensors can only be deemed as faulty by the car if they don't give a reading or they give readings outside of a certain set of parameters.
It is very possible for sensors to give readings inside parameters that just aren't correct, like wheel speed thinking there is a wheel skidding.

Also worth checking tyre pressures too (when cold) as you'd be surprised how sensitive the system can be.

[Keith Knight]

Re: ESP problems

Thanks for responding
Haven't checked the crankshaft rotation sensor or wires around the intercooler scoop. Will do that tomorrow. The type of issue I have is unlikely to be engine-based. It is far too infrequent and random, I think. I am leaning towards the ESP controller internals. It's just a shame you have to spend so much finding out.
Yaw sensor connected to steering column, I think. G-Force under seat - yes. Tyre pressures frequently checked. All reluctors perfect. Brake light switch OK (one of the 1st things i checked as it had already been replaced once). With trust plug light stays on but ESP sensors do not function. Engine should not then cut out down the road - which mine does!
The garage has a fully fledged star machine and there is a Smart specialist trained in Germany. They let me hang around - to help with my OCD (no joke, I do have OCD!).
Thanks for making me think. Please let me know if you think of anything else. I will post the results of my continued labours.
Keith

[Mad smart person]

Re: ESP problems

Greetings, I concur with 'evilution', if you've had the alignment checked, both front and rear suspension, more times than is good, the crank sensor is a good bet. If your local fully trained Star person hooks up to your car his/her Star machine and looks deep enough, they'll find there's a resistance measurement they can make from the ECU to see what the resistance is within spec. By chance, does the 'battery' symbol appear at the same time the triangle appears??? If the ECU doesn't know what the engine speed is, it has no idea what the fuel flow should be, what engine speed to go to on changing gear. Just a question here, when you've gone to fault mod and slowing down, if you put your foot flat on the throttle, does the car start 'bunny' hopping? Cheers, Ian.

[heinkeljb]

Re: ESP problems

Crank position sensor can be faulty whilst showing NO errors in MB Star. If it has an intermittent internal connection it could well show correct resistance, but still produce a fault condition. As you can get them for ~ £25 - £30, might be worth changing? Mine would just die, would restart after a while and work as if nothing had been wrong.

John

[Keith Knight]

Re: ESP problems

Ian and John,
Thanks so much for taking an interest. As for your questions: No battery symbol when warning triangle stays on. Engine/ignition is actually still running but will only idle. Yes to bunny-hops on flooring it. As for crank-position sensor, on the basis of elimination and cost, replacing that seems like a useful step before paying a 3rd party to test the ESP controller.

It is always difficult to know when a business you don't know offers a "test from £45" and then repairs up to a full exchange refurbished cost of nearly £500 - just how much "testing" they actually do before landing you with a big bill! This offer is on eBay, item no. 180883725299. It is under ESP/ABS components in car parts. The company is Autotek in Bournmouth run by Tony Gupta Car Parts. I haven't been able to find any other service like this, Smart want a lot more money for a new controller. They offer a 24hr tunrnaround which is good. Do I have any other options if replacing the crank sensor doesn't work? Of course I will encourage my garage to use the Star machine more thoroughly. I thought he was, actually - but I will raise your points.

It really is very nice of you all to take an interest in my annoying problem.

On a lighter note, I suffered the common rear PVC window hazing and shopping damage. I managed to obtain a back hood panel with window from CabrioWebshop in the Netherlands for £259 on ebay (item no: 130892648266). This is much cheaper than I had been quoted for the part before. I had various quotes for replacing the back PVC window alone from about £160 but (1) My panel was a bit scruffy and (2) the places were hundreds of miles from me and once you factor in petrol and travelling, I got a really good deal! It was a difficult (tight) fit but manageable. The trick, as on all modern parts is not to break the plastic bits. These were thin location tabs on the hood edges, which are under-engineered. I have now purchased some window material and once I have smartened up the removed panel, I will repair that with a bit of bonding and stitching and have myself a spare, if I ever need it.

On the whole the black Brabus Turbo, which was purchased off the Smart forecourt of SG Swansea in 2003; has performed admirably and has an iconic look, just like the old original mini did, before BMW ruined it; which is much admired. When I work out how (perhaps you could tell me?) I will post a photo. I think the trick will be to use the full HTML reply rather than "Quick" reply. I am just being lazy!

Thanks again everybody - I will keep you informed.
Keith

[2minits]

Re: ESP problems

Have you plugged it in when the fault is present? I know it sounds stupid but if turning the ignition off clears the fault..it could do just that, it needs plugging in when the light is on and the fault is active, that would at least tell you a rough place to start looking....

[Keith Knight]

Re: ESP problems

Thanks for replying
You are exactly right!! Would LOVE the opportunity to do this. The only way is to stall the car next time it happens, instead of switching off; leave everything the way it is and pay for a low-loader to recover me to the garage and even then, making sure nobody touches the ignition switch is going to be problematic as re-energising the electrics, even to first accessories postion may still clear the fault. Also, it is not possible to have a garage on call to act immediately and push the car around dead until it is tested. So, in all it is just not practicable or affordable.

I am going to speak to the mechanic about more detailed diagnostics and if this doesn't reveal anything, I will change the crank sensor first, check the clutch actuator wiring and then, if necessary send the ESP controller away for testing.

I can also earth the controller (the pin no. is on evilution, I think) to reset it and I think this can be done while the car is running with a press-to-make switch in the cabin. That is another route but not ideal. Many have had ESP problems with the Smart car. Of course on the 451 models it can easily be awitched off with the two buttons either side of the speedo but with such a short wheelbase car, this is not advisable for long periods. Its like a "fly-by-wire" plane. Without the electronics, it might just crash!

Thanks again for responding
Keith

[Evilution]

Re: ESP problems

I've never known fault codes to clear by turning off the ignition.

[Thrumbleux]

Re: ESP problems

Is it possible that the problem here is in the reverse order from assumed? So far the assumption is an ESP related fault is cutting power. Could it be that the power is cutting for whatever reason and for some associated reason the ESP (or signs of) is being invoked.
(Before everyone thinks I've lost the plot, Porsche had just such an issue with their 964 when first launched).

[Keith Knight]

Re: ESP problems

Thrumbleux
Thanks for responding. It was 2minnits (site sponsor) idea that turning the ignition off might clear the fault codes, not mine - since we had never seen any. I had just given up and it was a good a guess as any. As for the suggestion that the car is cutting out first - no, it isn't. In fact the engine doesn't completely cut out (which is why the battery light doesn't come on), it just wont permit any acceleration. I can't think of any other system that might stop me accelerating other than ESP. As for the Porsche 964 problem, that system is entirely different and various solutions were postulated, like airflow sensor, DME etc. I don't remember a recall so it must have been resolved somehow.
Thanks again. I have the car booked in for next week now so we will make sure the Star diagnostics suite is being properly utilised and try to find some errors, then replace the crank position sensor and then, if necessary have the ESP controller tested. Until then, I am staying off motorways and out of traffic in case it dies on me.
Keith