I've noticed multiple forum members reporting that they saw "Drivetrain malfunction", loss of power, and had to pull over.
There's a SIB on this issue and the car needs to go to the shop for software upgrade.
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SI B12 26 14
Engine Electrical Systems
September 2014
Technical Service
SUBJECT
VANOS Faults Stored in DME (Bosch)
MODEL
All models with the following engines and Bosch DME:
N20, N26, N55, N63T, S55, and S63T
Produced to 7/2014
SITUATION
The Service Engine Soon (MIL) is on and the engine could go into a reduced power mode with the
“Drivetrain Malfunction” message displayed.
One or more of the VANOS faults listed in the attachment are stored in the DME, although the engine is
mechanically sound and no unusual noises can be heard from the VANOS area.
These control faults relate to implausible camshaft position (intake or exhaust), the camshaft stuck situation,
or the camshaft angle offset to crankshaft outside the tolerance range.
CAUSE
Due to unfavorable Engine Position Management (EPM) parameters in the DME software, various VANOS
control faults could be set.
CORRECTION
Perform the recommended test plans using the latest version of ISTA/D. Correct any VANOS hardware issues
found, as indicated by the test plan.
After performing necessary repairs, or in case the ISTA test plan is inconclusive, program the vehicle using
the latest version of ISTA/P.