SB-10045702-3456

CARS

Date: 24.08.2012

Model: Evora from ‘11MY VIN BH_11179 Onwards

Number: 2012/13

Copy files should be maintained by:
Service Manager

Service Reception

Supervisor

Parts Manager

TITLE:
Incorrect Lotus TechCentre SRS (Supplementary Restraint System) live data information.
REASON:
The circuit descriptions displayed on the SDM squib resistance live data section within the current version of Lotus TechCentre (4.12.0) are incorrect when compared with the actual information received
from the systems SDM (Sensor & Diagnostic Module).
Dependant upon the nature of the SRS problem, this may make correct diagnosis and fault finding of
the SRS system difficult to achieve.
Note: Circuit descriptions displayed on TechCentre are still correct for any vehicles supplied with the
early SRS system equipped with forward mounted crash sensors located on each side of the front subframe (prior to 11MY VIN BH_11178).
Incorrect SDM live data display for ‘11MY Evora VIN BH_11179 Onwards

LINE DESCRIPTION
Line 1
Readings actually are
Line
2
Front Airbag
Passenger
Stage 2
___
Buckle Retractor
___
Line 3RH
Buckle Retractor LH
___
Line 4
Front Airbag Driver Stage 1
___
Line
5 Stage 2
Front Airbag
Driver
___
Front Airbag
Passenger
Stage 1
___
Line
6
Until Lotus TechCentre is rectified the descriptions against the resistance
values shown within the
Note:
‘squib’ live data section should actually read:
Line 1. Front airbag passenger stage 2.
Line 2. Buckle retractor RH
Line 3. Buckle retractor LH.
Line 4. Front airbag driver stage 1.
Line 5. Front airbag driver stage 2.
Line 6. Front airbag passenger stage 1.

Buckle retractor named as
Buckle Retractor Driver &
passenger.
The wiring does not change with
LHD to RHD & this needs to be
checked to see if it should be
described as Buckle Retractor
LH & Bucle Retractor RH

ACTION:
If any fault codes displayed within Lotus TechCentre indicates that there may be a potential SRS system
fault within the drivers airbag system then the following course of action is recommended.
Continued.....

Ohms
Ohms
Ohms
Ohms
Ohms
Ohms

CARS
Bulletin number 2012/13 continued
Page 2
Using the correct line information displayed on the previous page, if a high resistance reading indicates
a driver’s airbag circuit fault then the following diagnostic route is recommended in the first instance to
determine the cause of the problem.
Note: A resistance reading of 9.96 Ω on TechCentre indicates an open circuit, with typical resistance
values of 2.1 Ω - 3.2 Ω being acceptable.
WARNING: Please refer to all safety notices and procedures listed in service notes section WF.9 whilst
working on any area of the SRS system.
• Remove the lower steering column shroud - see service notes section VE.10 and check the continuity between the main harness clock spring connector & the SRS SDM module connector. The SDM
module is mounted in an alloy box bolted to the centre underside of the scuttle beam in front of the
centre console - see service notes section WF.8.
• Inspect the terminals at each connector and ensure that they have not been opened up thereby possibly causing an open circuit. The wire identification for the connectors is 369 LG/R, 370 LG/S, 371
LG/U & 372 LG/N - see service notes section MR.16b, Evora CCT diagrams sheet E1 for further
information.
SDM to clock spring
• If the terminals do not appear to have opened then temporarily harness connector
fit 2 suitable 2 ohm resistors across pins 1 & 2 (Driver stage 1)
& pins 3 & 4 (Driver stage 2) of the main harness clock spring
connector as shown in the right hand illustration.
• This will simulate the correct airbag resistances values, if you
can then clear the codes for the driver airbag this will indicate
if your problem is after this connector (within the clock spring /
airbag connections) & not within the main harness / SRS module part of the circuit.
Note: The majority of problems have been eventually been diagnosed as the pins within the connector housing on the airbag
side of the clock spring being forced & bent if the airbag connector has not been engaged carefully or due to an internal break
within the clock spring assembly.
Drivers airbag
The clock spring to SDM harness will harness connector
typically only fail if the main harness to
clock spring connector has not been
fully engaged into the clock spring
housing.

Suitable 2Ω
resistors fitted
across terminal
pins 1&2 and 3&4

sb173

Clock spring to
airbag connector
housing

CHARGES:
As per the current warranty policy and
procedures policy for diagnostic time
and rectification action apply.
SDM to clock spring
harness connector
Ends.