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

LI77.25-P-073749

Version

5

Function group

77.25 - Wind deflector (spoiler)

Date

10/18/23

Validity

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

Reason for change

Remedy added

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 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 outside of the target range (red) or final inspection is NOK:
--> Initialize the rear spoiler (if necessary up to 5x) until all values are in the target range (green).

NaN.NaN.NaN NaN:NaN:NaN
© Copyright Mercedes-Benz AG

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If subsequently OK: Subject the vehicle to a final inspection/test drive and hand it back to the customer if findings are
OK. If the customer subsequently experiences sporadic fault messages: A software remedy for this fault profile is currently being worked on (see below for SW release timeframe based on production date). At commencement of travel,
the spoiler can be completely extended manually via the button in the vehicle interior, in order to deactivate the automatic mode for this driving cycle and avoid an additional fault message in the instrument cluster.
If still NOK: Check screw connection of rear spoiler adjuster (see "Attachment 1") for tight seating (correct any smaller
deviations as necessary; SPECIFIED torque ~ 4.5 Nm).
*The looseness of screws does not compromise integrity of spoilers attachment to vehicle. Screw does not allow for
standard operation of spoiler when driving.*
•

•

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.

If screws are tight: Subject the vehicle to a final inspection/test drive and hand it back to the customer. Work on
a software remedy for this fault profile is currently in progress (see below for SW release timeframe based on
production date). At commencement of travel, the spoiler can be completely extended manually via the button in
the vehicle interior, in order to deactivate the automatic mode for this driving cycle and avoid an additional fault
message in the instrument cluster.
If screws are loose: 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 problem 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)
Photo of the label on the rear spoiler drive (IMPORTANT: Production/manufacturing date of the rear spoiler must
be easily readable) (For an example, see "Attachment 2")
Brief video recording of the loose screws of the rear spoiler adjuster

Current Timeline for Software Availability:
Facelift X290 ~ Beginning of December 2023
Modification Year 20/1 - 20/2 (MY Late 2019 through MY Early 2020) ~ Beginning of February 2024
Modification Year Start of Production -19/2 (Start of Production vehicles through MY Early 2019) ~ End of February
2024

Attachments
File
NaN.NaN.NaN NaN:NaN:NaN
© Copyright Mercedes-Benz AG

Description
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Schrauben_Aussteller.jpg

Attachment 1 - Screws

label_production_date.JPG

Attachment 2 - Rear Spoiler Production Date

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

Control unit/fault code
Control unit
NaN.NaN.NaN NaN:NaN:NaN
© Copyright Mercedes-Benz AG

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

Operation numbers/damage codes
Op. no.

Operation text

NaN.NaN.NaN NaN:NaN:NaN
© Copyright Mercedes-Benz AG

Time

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Damage
code

Note

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