Rear Spoiler Sporadically Nonfunctional
with Fault Message in Instrument Cluster
Topic number

LI77.25-P-073749

Version

3

Function group

77.25 - Wind deflector (spoiler)

Date

7/13/23

Validity

All X290 as of beginning of production without code U99/
U94

Reason for change

TIPS case information supplemented

Complaint
Rear spoiler sporadically remains in opened position or does not extend and a fault message appears in the instrument cluster.
The rear spoiler can then no longer be retracted manually using the button.
The function of the rear spoiler is re-established after an ignition reset and the fault message is no longer present in
the instrument cluster.

Cause
Possible causes:
•
•

Coding of the AMG DRIVE UNIT for recognition of Hall sensor when retracting rear spoiler.
Hardware tolerances / hardware wear

Remedy
If new software for the AMG DRIVE UNIT is available, carry out the software update.
If the vehicle already has the most current version of the AMG DRIVE UNIT software installed, conduct SCN coding of
the AMG DRIVE UNIT.
Then check the currently learned actual values under the path "DRVU -> Actual values -> Rear wing sensor system" (print AV screen prior to completing initialization -- if necessary):
If the values are all within the target range (green):
--> Subject the vehicle to a final inspection/test drive and, if the findings report is OK, return it to the customer.
If the values are not within the target range (red):
--> Re-initialize the rear spoiler (if necessary up to 5x) until all values are in the target area (green).
13.07.2023 12:24:34
© Copyright Mercedes-Benz AG

RROWELL

Page 1 / 2

If OK:
--> Subject the vehicle to a final inspection/test drive and, if the findings report is OK, return it to the customer.
if not OK
--> If the values are still outside of the target range even after repeated initialization (5x or more) or a fault message
appears again during the test drive
--> Create a TIPS case with the following information:

•
•
•
•

When exactly does the fault message appear (at which speed, when accelerating or braking, automatic mode,
etc.)?
Is the symptom sporadic or continuous?
Does the fault message disappear following an ignition reset/BUS idle and is the function of the rear spoiler then
(momentarily) restored?
Is the fault reproducible and if so, how?

Attach the following files:

•
•
•
•
•
•

Quick test
Control unit log for AMG DRIVE UNIT + rear wing (DRVU + HFL)
IC event memory
Currently learned actual values prior to initialization
Currently learned actual values following initialization
Power consumption of rear spoiler (XENTRY: Configuration -> Coding -> Coding of power parameter)

Symptoms
Body > Body/Cab > Spoiler > Does not move in/out

Control unit/fault code
Control unit

Fault text

N145/1 - AMG DRIVE UNIT (AMG DRVU) (DRVU_NG)

Operation numbers/damage codes
Op. no.

Operation text

13.07.2023 12:24:34
© Copyright Mercedes-Benz AG

Time

RROWELL

Damage
code

Note

Page 2 / 2