Vehicle does not start, plug X292x1/X296x1 not engaged correctly
Topic number

LI54.18-P-079535

Version

2

Function group

54.18 - Cable harnesses

Date

8/5/25

Validity

290679, 206080, 206280, 232482, 192382, 223182

Reason for change

Attachment translation

Complaint

Vehicle does not start, can also not be driven electrically.
The following fault messages are displayed in the instrument cluster:
•
•

Red fault message "HV battery" with the addition "Towing not possible"
Vehicle start not possible in yellow

Cause

Plug X292x1 / X296x1 not engaged correctly or plug defective.

Remedy

Requirement:
Before carrying out test work, it must be ensured that the person performing the work has successfully completed the
required qualification for work on the high-voltage system.
Test:
Check plug X292x1 / X296x1 as follows:
•
•
•

Please first take a photo of the plug X292x1 / X296x1 before carrying out further checks.
If a gap can be seen between the outer housing and plug housing of the plug X292x1 / X296x1, the plug
X292x1 / X296x1 is not engaged correctly, see "Plug assembly" Annex. Please open a TIPS case and attach a
photo of plug X292x1 / X296x1.
Disconnect the plug X292x1 / X296x1 and try to shift the outer housing with the interlock plug above forward in a disconnected state. If this is not possible, the plug X292x1 / X296x1 is OK, see video "Check plug
X292x1_X296x1_OK state" in Annex.

If this check confirms that the outer housing can be shifted forward despite the disconnected plug X292x1 / X296x1,
the plug X292x1 / X296x1 including wiring harness is not OK (please attach video) and must be replaced. Please attach a photo of the label to the TIPS case, see Annex "Position of label"
Assembly:

05.08.2025 20:39
© Copyright Mercedes-Benz AG

CCUSHWA

Page 1 / 3

If the outer housing cannot be shifted forward after the check above, then the plug X292x1 / X296x1 can be installed
properly as per the "Plug assembly" instructions, see Annex.
Important note:
If the plug was installed correctly, no gap between the outer housing and plug housing must be visible, see picture 5
from "Plug assembly" instructions Annex.
There is no additional engaging for the outer housing. In addition, the plug X292x1 / X296x1 must be fixed in place
with a cable tie, see "Gap / cable tie note" picture in the Annex.

Attachments
File

Description

Position Label_Etikett.jpg

Position of label

Stecker X292x1_X296x1 prüfen_iO Zustand.mp4

Check plug X292x1_X296x1_OK state

Stecker X292x1_296x1_english connector.jpg

Gap / cable zip tie position

Stecker X292x1_296x1_english connector closing.jpg

Plug assembly instructions

05.08.2025 20:39
© Copyright Mercedes-Benz AG

CCUSHWA

Page 2 / 3

Disclaimer
NOTE: The information contained in this document is intended for use by trained, professional technicians with the
knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz
approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and
provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect
is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a
symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes
resulting in the same or similar symptoms or conditions described in this document, and trained professional service
technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained
in this document does not guarantee warranty coverage nor does it extend the vehicle’s warranty in any way.

Symptoms
Power generation > Engine management > Engine start/stop > Does not start
Overall vehicle > Power supply > High-voltage on-board electrical system > High-voltage battery > Malfunction
Overall vehicle > Power supply > High-voltage on-board electrical system > High-voltage battery > Display message
Overall vehicle > Power supply > Fuel cell > Display message

Control unit/fault code
Control unit

Fault text

N127 - Control unit "Drivetrain" (PTCU) (CPC3AMG)

P154700 - There is a warning due to a detected fault in
the interlock circuit. _

G2/3 - Starter-alternator (SG-EM) (HVRSGG10_AMG)

P0A0A00 - The interlock circuit of the high-voltage onboard electrical system has an electrical fault. _
P0A0B00 - The interlock circuit of the high-voltage onboard electrical system has a malfunction. _

Operation numbers/damage codes
Op. no.

Operation text

Time

Damage
code

Note

547940

Replace cable set

H

540U774

Plug X292x1

05.08.2025 20:39
© Copyright Mercedes-Benz AG

CCUSHWA

Page 3 / 3