ACS fault help

[Sean d]

Guys, I took the Z for a shakedown today and all was well until I got the back end out, acs light came on and didn't go out, I don't think it even kicked in, after a restart it reset itself but stored the code 50 throttle accuator,
Any ideas would be most welcome thanks

 

[Mario]

On the intake side between just after the MAF there are two throttle bodies in series, the ASC actuated one and then after the pedal actuated one, on the first one try to remove it and see if the butterfly it´s seized, I believe in normal operation its fully open and when the ASC kicks in the butterfly closes to cut power, I suspect your one tried to close and either the butterfly it´s seized or the motor is not working, not sure if you can test the motor/solenoid somehow by applying some voltage and see if it moves.

 

[Sean d]

On the intake side between just after the MAF there are two throttle bodies in series, the ASC actuated one and then after the pedal actuated one, on the first one try to remove it and see if the butterfly it´s seized, I believe in normal operation its fully open and when the ASC kicks in the butterfly closes to cut power, I suspect your one tried to close and either the butterfly it´s seized or the motor is not working, not sure if you can test the motor/solenoid somehow by applying some voltage and see if it moves.

Thanks for that Mario, just found this article on deleting the ACS throttle so it shows really clearly what you where saying, I won't be deleting it but it makes sense for track cars.
http://www.eatsleeptinker.com/2014/06/02/asc-throttle-body-delete/

 

[mrscalex]

Thanks for that Mario, just found this article on deleting the ACS throttle so it shows really clearly what you where saying, I won't be deleting it but it makes sense for track cars.
http://www.eatsleeptinker.com/2014/06/02/asc-throttle-body-delete/

I'd hazard a guess the mod would be an MOT fail anyway. If only because it talks about removing the ASC bulb on the dash to hide the ensuing error which an eagle eyed tester would spot and fail when it doesn't illuminate during ignition.

 

[Sean d]

As mentioned Robert, it would suit track cars

 

[Ianmc]

My Z3 doesn't have ASC (or DSC) and its had no related MOT issues.

 

[mrscalex]

My Z3 doesn't have ASC (or DSC) and its had no related MOT issues.

So you’ve done the mod?

 

[Ianmc]

So you’ve done the mod?

No mod, it's as factory. Very early cars didn't have it, bit like no separate sidelights, which are contained in the main light unit.

 

[mrscalex]

No mod, it's as factory. Very early cars didn't have it, bit like no separate sidelights, which are contained in the main light unit.

It wouldn’t be an issue for the MOT then if it left the factory like that.

 

[Ianmc]

It wouldn’t be an issue for the MOT then if it left the factory like that.

Exactly, but it would need to be a very clued up MOT tester to fail a car that had ASC removed, I would have thought, when it was not installed/an optional extra in some?

 

[mrscalex]

Exactly, but it would need to be a very clued up MOT tester to fail a car that had ASC removed, I would have thought, when it was not installed/an optional extra in some?

He works at my local test station.

In fact I owe him. I'd cleared the errors on the ABS by replacing wheel sensors and the control unit. And I did think it was funny I'd never observed the system kick in. He discovered that the bulb had been removed from the dash as he didn't see it briefly light when the key was turned in the ignition.

I then found out if the bulb is removed the ABS is actually switched off. And no errors are recorded.

 

[mrscalex]

Although the flip side is he puts advisories down if he sees the faintest hint of surface rust. Which I'm anything but happy about. Even my 2 year old 3 Series has surface rust on the suspension.

 

[Ianmc]

I suppose a give away is if you have an ASC switch in the car. If it doesn't light up a bulb when pressed, likely the bulb has blown or the bulb has been removed. Happy with my 25% LSD, no electrics or switch!

 

[Sean d]

I suppose a give away is if you have an ASC switch in the car. If it doesn't light up a bulb when pressed, likely the bulb has blown or the bulb has been removed. Happy with my 25% LSD, no electrics or switch!

A resistor can be used so the light functions as normal