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Technical Service Bulletin
Topic

Seat Belt and Safe Guard Alerts - Mechanical malfunction DTC B101C07 evident within
0015

Market area

Bentley: worldwide (2WBE),China 796 VW Import Comp. Ltd (Vico), Beijing (6796)

Brand

Bentley

Transaction
No.

2079835/1

Level

EH

Status

Released for publishing

Release date

Jan 20, 2026

Diagnostic trouble codes

Diagnostic
address

Diagnostic trouble code

Fault
symptom

Storage
state

0015 - Airbag

B101C07: Driver seat belt switch mechanical
malfunction

Intermittent

0015 - Airbag

B101C07: Driver seat belt switch mechanical
malfunction

static

New customer code

Object of complaint

Complaint type

lighting, signaling -> acoustic signals -> seat belt usage
audio warning

functionality -> warning tone sounds
without cause

occupant protection, passenger protection -> operation,
activation -> belt warning

functionality -> does not switch off
/disconnect

occupant protection, passenger protection -> operation,
activation -> belt warning

functionality -> warning tone sounds
without cause

lighting, signaling -> acoustic signals -> seat belt usage
audio warning

functionality -> does not end

Vehicle data
24-26MY | All Models
Sales types

Type MY
***

Brand Designation Engine code Gearbox code Final drive code

2024 E

*

*

*

Position

***

2025 E

*

*

*

***

2026 E

*

*

*

Documents
Document name
master.xml

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Technical Service Bulletin
Seat Belt and Safe Guard Alerts - Mechanical malfunction DTC B101C07 evident
within 0015

Transaction No.:

2079835/1
Release date: Jan 20,
2026

Condition
Customer Statement
While driving, the seat belt warning system suddenly comes on and a system safe guard warning also
appears in the Driver’s Instrument Panel (DIP).
Workshop Findings
Customer statement can be verified and the following DTC is stored in the airbag control module (address
word 0015):
•

B101C07: Driver seat belt switch mechanical malfunction (passive/sporadic)

Technical Background
If no change in seat belt status—meaning the insertion or removal of the Seat belt latch insert as monitored
by the buckle switch—is detected over five consecutive driving cycles, the airbag control unit (diagnostic
address 0015) stores the DTC ‘B101C07: Driver seat belt switch mechanical malfunction, static’ in the event
memory.
A safe guard warning also appears in the instrument cluster, as it is suspected that a belt dummy is being
used. If the seatbelt was kept permanently latched while the vehicle was in use, clarification is needed from
the customer to confirm that the seatbelt was operated as intended—latched and unlatched during each
drive cycle.
If the DTC shown above is present and the customer confirms that the seatbelt is operating as intended,
please raise a full technical DISS query.

This safety feature will be implemented in all current and future Bentley models.

A driving cycle is: unlock door, open door, close door, fasten seat belt, switch ignition on and drive, then
stop, unfasten seat belt, switch ignition off, open door to exit vehicle, close and lock door.
A change in belt status means: The insertion and removal of the latch insert is monitored by a microswitch.
A belt dummy is a latch insert in the belt buckle that is intended to suppress the visual and acoustic warnings
that are triggered by the belt-fastened sensor if the seat belt is not fastened. The same symptom is identified
if the driver inserts the seat belt in the belt buckle and sits on top of the fastened belt, i.e. does not wear the
seat belt. Another variant is if the front passenger’s seat belt is inserted in the driver’s belt buckle.
One driving cycle with correct use of the seat belt is enough to change the event memory entry in the airbag
control unit to “intermittent”. The pre sense warning no longer appears as a result.

Production Solution

Not applicable

Service
Customer Communication Guidance
Please inform the customer that Bentley’s safety systems are designed to function optimally only when the
seat belt is worn correctly. The seat belt warning system, including the belt recognition feature, serves as a
prompt to encourage proper usage and to reinforce the importance of seat belt safety.
If the customer completes a full driving cycle with the seat belt fastened correctly, the event memory entry in
the airbag control unit will be marked as intermittent. Consequently, the warning will no longer be displayed,
and it is not necessary to manually erase the event memory.
Additional Technical Context:
The airbag control unit may log a diagnostic trouble code (DTC) if it detects repeated instances of the seat
belt being unfastened during driving. This can occur in two scenarios:
•

The ECU assumes a mechanical fault in the belt buckle due to inconsistent or incorrect seat belt usage.

•

Alternatively, if the customer regularly drives with the seat belt disconnected and ignores the warning
chime, the system interprets this behaviour as a potential mechanical malfunction.

In these cases, confirm with the customer how they are using the seatbelt. Specifically, verify whether they
are using any device or accessory that could interfere with the buckle recognition system, or if the seatbelt is
not being used as designed.
Before raising a full technical DISS query, confirm that no defeat device or dummy buckle is being used and
that the seatbelt is being operated as intended.

Warranty
It is not permitted to replace the belt buckle.
Billing is not possible as this is not a technical problem.