Loss of power & won't change gear in automatic mode. Please help!

[Sct73]

Can anyone help please? Roadster lost all power on motorway, now will only crawl along with very slow acceleration and will not automatically change gear. Switch to manual and it changes fine but still only crawls along.
Is this safe mode?
How do I fix it?
Thanks in advance

[tolsen]

Can be caused by turbo over boost. Engine goes into limp mode and reason why it won't change in auto is you can't get revs high enough. Common cause for turbo over boost is the clip that connect wastegate actuator rod to wastegate arm has come off. Could also be stiff wastegate actuator so get under your car and check it out.

[BBE]

Yes, that sounds like safe mode.
Try disconnecting the battery for a few minutes, then reconnect and test (obs radio code if original radio).
If this fixes the problem then it will most likely come back later. Could be a bad cycle valve ++.
If problem still present, crawl under the engine and look for a disconnected linkage between the turbo actuator and the wastegate..
A new circlip, preferably stainless, is needed..
Bjorn