Throttle pressed ESP lamp comes on

[AL SMART]

Fortwo Coupe WME450332 chassis

Vehicle running wont rev up.As soon as throttle pressed ESP lamp comes on and revs stay around 1800RPM.I have tried new throttle body and an ESP control unit.I have disconnected the alternator and tried a new MAP sensor.I have tried another throttle pedal and checked wiring for any open or short circuits.All appears ok.HELP!!!!!

[smartone]

Originally Posted by AL SMART

Fortwo Coupe WME450332 chassis

Vehicle running wont rev up.As soon as throttle pressed ESP lamp comes on and revs stay around 1800RPM.I have tried new throttle body and an ESP control unit.I have disconnected the alternator and tried a new MAP sensor.I have tried another throttle pedal and checked wiring for any open or short circuits.All appears ok.HELP!!!!!

with the esp light coming on it suggests not an engine/throttle related fault.

the esp system is sensing loss of traction or car unstable for some reason.

i would start by checking reluctor rings for cracks/corrosion and also resistence of all 4 wheel speed sensors,good sensor should be approx 0.9-1.1kohm.

also another possible cause could be the lateral sensor also known as yaw rate this is located on underside of floor in centre almost underneath the gear lever,this could be sensing the car is trying to flip or something and is cutting power to try and control it.

[coolfart]

From what you are saying, the car is doing this without moving anywhere????

If this is so, then I don't think it can be any of the above suggestions, which will only be affected when the car is moving!

It sounds like it's going to 'safe' mode for some reason.....think you will need to find a local garage (or call fudgesmart, to see if he is passing your way soon?) who can connect to star machine & get the fault codes read.
Only problem with electronics on modern cars, you can't really tell where the problem is without knowing the fault code to find where the source of the problem is! Sorry if that sounds confusing, but I'm sure you know what I mean!

I would stop just throwing different parts on it, until you can get the codes read.

[smartone]

i personally do not think it is safe mode as ESP does not normally come on in safe mode as far as i am aware???

also the possible faults i suggested can occur if static if the sensors are giving duff readings,one of the abs speed sensors could be giving a reading when revved static similar to having a driven wheel jacked up and trying to drive it the esp will stop it powering,i get it happen at work on the trains quite a lot the speedo will fluctuate when static because of iffy readings from WSP probe on axle (speed sensor same as abs).also if the lateral sensor has failed internally then it could tell the ecu to cut power the same as if the car was out of control in bends etc.agreed cracked reluctors will only become apparent when moving.

it could be faulty sensor or the wiring is picking up a voltage spike or something.
but as coolfart says getting it plugged in to have codes read will help to point you in the right direction,i was merely pointing out some possible causes to the problem you have.

[AL SMART]

Disconnected ESP control unit which would isolate any sensors and fault still there.
Disconnected steering wheel and fault still there.
Main dealer siad fault codes were throttle actuator and ESP control unit which i have already changed.

[smartbear1]

if you have changed the throttle body and the esp unit to no avail then it may be the wiring going to the offending items?
look to see if its chaffed/broken