Technical product information
Topic
Market area
Brand
Transaction No.
Level
Status
Release date

PSIS 750600B0001 Wiring modification for seat belt pre-tensioner buckle switches
Bentley: worldwide (2WBE)
Bentley
2037995/4
EH
Approval

New customer code
Object of complaint

Complaint type Position

occupant protection, pedestrian protection -> seat belts, 1st row functionality

Vehicle data
Arnage and Silver Seraph
Sales types
Type
0D2BL6
0D2BL6
3Z22K6
3Z22K6

MY
1998
1999
1998
1999

Brand Designation Engine code
E
Z1J
E
Z1J
E
Z1H
E
Z1H

Gearbox code
Z1C
Z1C
Z1C
Z1C

Final drive code
-

Chas is numbers
Manufacturer Filler Type Filler MY Factory From

To

SCB
SCB
SCA
SCA
SCA
SCA
SCA
SCA

X01033
X03050
X01106
X03051
H03051
H01033
H03050
H01106

***
***
***
***
***
***
***
***

**
**
**
**
**
**
**
**

Documents
Document name
master.xml
750600b0001_deu.pdf
750600b0001_eng.pdf
750600b0001_esp.pdf
750600b0001_fra.pdf
750600b0001_ita.pdf

*
*
*
*
*
*
*
*

*
*
*
*
*
*
*
*

C
C
C
C
C
C
C
C

X01001
X01107
X01002
X01078
H01078
H01001
H01107
H01002

Prod from Prod to

Technical product information
PSIS 750600B0001 Wiring modification for seat belt pre-tensioner buckle switches

Transaction No.: 2037995/4

Customer statement / workshop findings
This PSIS has been issued to inform parts and service personnel of a wiring modification to the buckle switches on the seat belt pre-tensioners.
If a vehicle enters the workshop with an owner complaint of airbag warning light illumination and codes are stored for;
Drivers seat belt buckle switch resistance undefined – intermittent
Passenger seat belt buckle switch resistance undefined – intermittent
Then the following modification to the wiring should be carried out.

Technical background
Heritage PSIS (Product Support Information Sheet). Reference attached PDF for details

Production change
Reference attached PDF for details

Measure
Reference attached PDF for details

Wiring modification for seat belt pre-tensioner buckle
switches
P.S.I.S. 750600B0001
Author Tim Badger
-------------------------------------------------------------------------------------------------

Applicable to
Model

Model
Year

From VIN

Bentley Arnage

1998

SCBLB51E9WCX01001 SCBLB51E0WCX01033

Bentley Arnage

1999

SCBLB51E8XCH01107 SCBLB51E8XCX03050

Rolls-Royce Silver Seraph

1998

SCALA61E4WCX01002 SCALA61E1WCH01106

Rolls-Royce Silver Seraph

1999

SCALA61E9XCH01078 SCALA61E3XCX03051

To VIN

-------------------------------------------------------------------------------------------------

Introduction
This Product Support Information Sheet has been issued to inform parts and service personnel
of a wiring modification to the buckle switches on the seat belt pre-tensioners. If a vehicle
enters the workshop with an owner complaint of airbag warning light illumination and codes
are stored for;
Drivers seat belt buckle switch resistance undefined - intermittent
Passenger seat belt buckle switch resistance undefined - intermittent
then the following modification to the wiring should be carried out.
-------------------------------------------------------------------------------------------------

Description
It has become apparent in service that an increase in the electrical resistance of the wiring for
the seat belt buckle switches may be experienced in certain circumstances. This resistance
increase is caused by the formation of oxides in the harness terminals of two connectors
applicable to this circuit.

______________________________________________________________________
PSIS 750600B0001-1

© Bentley Motors Limited

Because the buckle switch circuit is of a low voltage / low current type, this resistance increase
can disrupt the passage of data from the buckle switch to the airbag control module. When this
is detected the airbag warning light will be illuminated and the codes listed above will be stored.
This modification involves the rewiring of the buckle switch circuit, so that these two
connectors are not utilised. For clarification this procedure is broken down into two parts,
right-hand drive vehicles and left-hand drive vehicles.
-------------------------------------------------------------------------------------------------

Procedure
Before commencing work on the vehicle;
Unbolt and carefully tilt back both front seats as described in ASSIST - Workshop information.
Pull back the carpet on both sides of the console as described in ASSIST - Workshop
information.
-------------------------------------------------------------------------------------------------

RIGHT-HAND DRIVE VEHICLES
Drivers side
1. Remove drivers footrest and passengers false floor as described in ASSIST - Workshop
information.
2. Locate the seat belt buckle switch connector (X1406) under the drivers seat and disconnect.
3. Using electrical tape fully insulate the connector.
4. Place the new connector on the link loom next to the original so that the correct length of
harness can be obtained. Then double back the original connector and tape to the harness using
electrical tape. Reconnect the switch connector.
5. Tie wrap the link loom to the seat harness as far as the console.
6. Remove the 8 mm bolt which retains the rear footwell ducting and feed the link loom under
the ducting so that it lies against the transmission tunnel.
7. Resecure the ducting.
8. With reference to figure 1 locate connector X1456.
9. On the female side of the connector cut the following cables as near to the terminal as
possible;
______________________________________________________________________
PSIS 750600B0001-2

© Bentley Motors Limited

Black slate at cavity 13
Black green at cavity 18
10. Fit a piece of the heat shrink sleeve to both of these cables.
11. Splice and then solder the black slate cable on the link loom to the black slate cable cut at
operation 9. Repeat this operation with the black green cables.
12. Using a heat gun shrink down the sleeving on both splices.
Passenger side
1. Feed the link loom over the transmission tunnel following the route of the main harness at
the front of the console under the heater box.
2. Remove the 8mm bolt which retains the rear footwell duct and feed the link loom under it
so that it lies against the transmission tunnel. Resecure the footwell ducting.
3. Disconnect the connector (X1417) for the seat belt buckle switch under the passenger seat.
Tape up this connector so that it is fully insulated.
4. Place the new connector on the link loom next to the original so that the correct length of
harness can be obtained. Then double back the original connector and tape to the harness using
electrical tape. Reconnect the switch connector.
5. Tie wrap the new link loom to the seat harness as far as the console.
6. Run the link loom under the console carpet ensuring that there is a clearance to the false
floor mounts.
7. On the female side of connector X1456 cut the following cables as near to the terminal as
possible;
Slate black at cavity 19
Black blue at cavity 20
8. Fit a piece of heat shrink to both of these cables.
9. Splice and then solder the slate black cable on the link loom to the slate black cable cut at
operation 7. Repeat this operation with the black blue cables.
10. Using a heat gun shrink down the sleeving on each splice.
Power splice
1. With reference to figure 1 identify connector X1457.
______________________________________________________________________
PSIS 750600B0001-3

© Bentley Motors Limited

2. On the female side of this connector cut the yellow cable at cavity 1. The cut should be
made approximately 2 inches (50 mm) from the terminal. Strip back the insulation on each side
of the cut and fit a piece of heat shrink.
3. Splice and solder together the two yellow cables from the link looms and the two yellow
cables stripped at connector X1457. This splice should have two cables on each side of it.
4. Using a heat gun shrink the sleeving onto the splice.
5. Tidy up all the splices and ensure that they will not foul on the foot rest or it's mounts.
6. Clear the stored fault code with the GDS machine and exit the diagnostic routine.
7. Start the car and check that the airbag warning light does not illuminate.
8. Disconnect the passengers buckle switch and check that the warning light illuminates. Turn
off the engine.
9. Re enter the airbag diagnostic routine and check that the code for undefined resistance of
the passenger buckle switch is stored.
10. Reconnect the buckle switch. Clear the code and then exit diagnostics fully.
11. Rebuild the vehicle.

______________________________________________________________________
PSIS 750600B0001-4

© Bentley Motors Limited

Figure 1 Right-hand drive vehicles
-------------------------------------------------------------------------------------------------

LEFT-HAND DRIVE VEHICLES
Drivers side
1. Remove the carpets on the drivers side of the vehicle and the passengers false floor as
described in ASSIST - Workshop information.
2. Feed the link loom over the transmission tunnel following the route of the main harness at
the front of the console under the heater box.

______________________________________________________________________
PSIS 750600B0001-5

© Bentley Motors Limited

3. Remove the 8 mm bolt which retains the rear footwell duct and feed the link loom under it
so that it lies against the transmission tunnel. Resecure the rear footwell ducting.
4. Locate the seat belt buckle switch connector (X1285) under the drivers seat and disconnect.
Using electrical tape fully insulate the connector.
5. Place the new connector on the link loom next to the original so that the correct length of
harness can be obtained. Then double back the original connector and tape to the harness using
electrical tape. Reconnect the buckle switch connector.
6. Tie wrap the new link loom to the seat harness as far as the console.
7. Run the link loom under the console carpet ensuring that the loom clears any moving parts.
8. With reference to figure 2 locate connector X1247.
9. On the female side of this connector cut the following cables as near to the terminal as
possible:
Black slate at cavity 13
Black green at cavity 18
10. Fit a piece of heat shrink to each of these cables.
11. Splice and then solder the black slate cable on the link loom to the black slate cable cut at
operation 9. Repeat this operation with the black green cables.
12. Using a heat gun shrink down the sleeving on each splice.
Passenger side
1. Locate the seat belt buckle switch connector (X1317) under the passenger seat and
disconnect.
2. Using electrical tape fully insulate the connector.
3. Place the new connector on the link loom next to the original so that the correct length of
harness can be obtained. Then double back the original connector and tape to the harness using
electrical tape. Reconnect the switch connector.
4. Tie wrap the link loom to the seat harness as far as the console.
5. Remove the 8 mm bolt which retains the rear footwell ducting and feed the link loom under
the ducting. Lie the link loom against the transmission tunnel so that it clears the false floor
mounts.
6. Resecure the ducting.
______________________________________________________________________
PSIS 750600B0001-6

© Bentley Motors Limited

7. On the female side of connector X1247 cut the following cables as near to the terminal as
possible:
Slate black at cavity 19
Black blue at cavity 20
8. Fit a piece of heat shrink sleeve to both of these cables.
9. Splice and then solder the slate black cable on the link loom to the slate black cable cut at
operation 7. Repeat this operation with the black blue cables.
10. Using a heat gun shrink down the sleeving on both splices.
Power splice
1. With reference to figure 2 identify connector X1239.
2. On the female side of this connector cut the yellow cable at cavity 1. The cut should be
made approximately 2 inches (50 mm) from the terminal. Strip back the insulation on each side
of the cut. Apply a piece of heat shrink to one of the cables.
3. Splice and then solder together the two yellow cables from the link looms and the two
yellow cables stripped at connector X 1239. The splice should have two cables on each side of
it.
4. Using a heat gun shrink the sleeving onto the splice.
5. Tidy up all the splices and ensure that they will not foul the false floor or it's mounts.
6. Clear the stored fault code with the GDS machine and exit the diagnostic routine.
7. Start the car and check that the airbag warning light does not illuminate.
8. Disconnect the passenger buckle switch and check that the warning light illuminates. Turn off
the engine.
9. Re enter the airbag diagnostic routine and check that the code for undefined resistance of
the passenger buckle switch is stored.
10. Reconnect the buckle switch. Clear the code and then exit diagnostics fully.
11. Rebuild the vehicle.

______________________________________________________________________
PSIS 750600B0001-7

© Bentley Motors Limited

Figure 2 Left-hand drive vehicles
-------------------------------------------------------------------------------------------------

______________________________________________________________________
PSIS 750600B0001-8

© Bentley Motors Limited

Wiring diagram

______________________________________________________________________
PSIS 750600B0001-9

© Bentley Motors Limited

A Air bag control module
B Secondary fusebox
C Drivers seat belt switch
D Passengers seat belt switch
E New connector - drivers seat belt switch
F New connector - passengers seat belt switch
Solid line on diagram designates original circuit
Dashed line on diagram designates new link loom

-------------------------------------------------------------------------------------------------

Parts affected
New part number Description

Displaced part number Quantity

PM 58150PA

Right-hand drive kit -

1 off

PM 58151PA

Left-hand drive kit -

1 off

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Parts availability
Parts now in stock.
-------------------------------------------------------------------------------------------------

Defect and Repair code manual
Defect code Repair code Time
75 06 27 99 99 75 06 27 99 S 3.0 hours

______________________________________________________________________
PSIS 750600B0001-10

© Bentley Motors Limited