Loss of power (smart roadster)

[diggler]

I have a smart roadster coupe (brabus) and recently has entered into a safe mode(no lights have came on the dash) which has dramatically dropped the power. it still makes the same noise and still functions but feels like the turbo is not being used at all.

I disconnected the battery and reconnected it and the safe mode went off(turbo working fine with normal power again) for about 5 minutes but then came back on.

I have read that this may be someething to do with the turbo and the actuator arm which i checked and it is still on with the clip attached.

Im not sure what to do/check next.

Any suggestions?

[krassegrand]

Re: Loss of power (smart roadster)

Do You have a boost gauge?
If the cycle valve does not regulate the pressure it will go into a kind of safe mode with no lights comming on but there will be a fault code to be read. If the fault code is "turbo pressure out of limits" it is most likely the cycle valve.
Cheap part but a bit irritating to change. Give a couple of hours for the DIY job.

Jörgen

[diggler]

Re: Loss of power (smart roadster)

the boost gauge goes upto zero and then back down when i change up a gear. so basically no boost. but it does give a reading when driving

[krassegrand]

Re: Loss of power (smart roadster)

Yes but if You turn the car of, does it drive normally at first?
How high does the boost go before it goes into "safe mode"?

Jörgen

[137699]

Re: Loss of power (smart roadster)

Classic symptoms of a failed cycle valve. Very common issue. I've had it happen twice before and am now on my 3rd cycle valve. And both times, no fault code was stored.

[diggler]

Re: Loss of power (smart roadster)

Yes but if You turn the car of, does it drive normally at first?
How high does the boost go before it goes into "safe mode"?

Jörgen

it goes upto about 1.5 bar when i reset the battery and its not in safe mode, is this normal?

[diggler]

Re: Loss of power (smart roadster)

Classic symptoms of a failed cycle valve. Very common issue. I've had it happen twice before and am now on my 3rd cycle valve. And both times, no fault code was stored.

Did you have the same problem with the safe mode? and can it be the cycle valve that is faulty because when i take the battery off and put it back on it works normally for roughly 5 minutes again?

[137699]

Re: Loss of power (smart roadster)

Did you have the same problem with the safe mode? and can it be the cycle valve that is faulty because when i take the battery off and put it back on it works normally for roughly 5 minutes again?

Yes exactly the same - disconnecting the battery just resets the ECU which means safe mode is disabled until the turbo boosts unexpectedly (caused by cycle valve not controlling boost properly) then safe mode is activated to prevent damage occurring.

[diggler]

Re: Loss of power (smart roadster)

Yes exactly the same - disconnecting the battery just resets the ECU which means safe mode is disabled until the turbo boosts unexpectedly (caused by cycle valve not controlling boost properly) then safe mode is activated to prevent damage occurring.

Ok thanks a lot for your help. cycle valve ordered and next weekend probably ruined ha!

[krassegrand]

Re: Loss of power (smart roadster)

Ok thanks a lot for your help. cycle valve ordered and next weekend probably ruined ha!

Good luck!
Are You changing it Yourself?

Jörgen

[diggler]

Re: Loss of power (smart roadster)

Good luck!
Are You changing it Yourself?

Jörgen

im going to try, i found a few guides online on the best way to take the back panels off to get near the component.

should save me a decent ammount of money on labour costs and the cycle valve was only £18

[krassegrand]

Re: Loss of power (smart roadster)

It is not that hard to do.
Get back on the forum if You have any problems or when You are ready.

Jörgen

[diggler]

Re: Loss of power (smart roadster)

Just an update at the current stage of repair:

i got a diagnostic test on the car from a friend who had the equipment and got these error codes,

P2052: Boost pressure standard deviation 1
P2011: Boost pressure.


I'm hoping these are the codes for a faulty cycle valve otherwise i have wasted my money!

does anyone know what these codes link to?

[Big Performance]

Re: Loss of power (smart roadster)

Cycle valve and/or wastegate

[krassegrand]

Re: Loss of power (smart roadster)

The same codes as I had when the cycle valve was gone.

Jörgen