ignition RENAULT SCENIC 2011 J95 / 3.G Air Bag ACU4 - Seat Belt Pretensioners Workshop Manual

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Introduction
88C - 2
88C
V3 MR-372-J84-88C000$010.mif
188C
AIRBAG ACU4
Vdiag: 04
AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Introduction
1. SCOPE OF THIS DOCUMENT
This document presents the fault finding method applicable to all computers with the following specifications:
2. PREREQUISITES FOR FAULT FINDING
Documentation type
Fault finding procedures (this manual):
– Assisted fault finding (incorporated into the diagnostic tool), paper version (Workshop Repair Manual
or Technical Note) and Dialogys.
Wiring Diagrams:
– Visu-Diagram (CD-ROM), paper.
Type of diagnostic tools:
–CLIP
Special tooling required:Véhicule: SCENIC II
Function concerned: AIRBAGName of computer: AUTOLIV - ACU 4
Program no.:
Vdiag No.: 04
SPECIAL TOOLING REQUIRED
– Multimeter.
– Set of adapters and terminal blocks for using the airbag and
pretensioner wiring harness check function of CLIP and XRBAG
tools for updates including the terminal blocks listed below.
– Modifying the series of new airbag ignition module
connectors entails modifying the dummy ignition module.
LOCAL MODIFICATION OF THE DUMMY IGNITION MODULE:
–Remove the ignition module from its red mounting and
remove one of the brown locking notches.
– 22-track computer terminal block: Elé. 1685
– 64-track computer terminal block: Elé. 1717
– 22-track seat terminal block: Elé. 1687
– 10-track rotary switch terminal block: Elé. 1617
ACU4 Vdiag04 J84 1.0
MR-372-J84-88C000$010.mif

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Introduction
88C
88C - 3V3 MR-372-J84-88C000$010.mif
AIRBAG ACU4
Vdiag: 04
3. REMINDERS
Procedure:
To run diagnostics on the vehicle's computers, switch on the ignition in fault finding mode (+ after ignition forced
setting):
– vehicle card in card reader.
– Press and hold start button (longer than 5 seconds) with start-up conditions not fulfilled,
– Then connect the diagnostic tool and perform the required operations.
+ After ignition feed cut-out is performed as follows:
– Disconnect the diagnostic tool,
– Press the start button twice briefly (less then 3 seconds),
– See that the + after ignition feed has been cut off by checking that the computer warning lights on the instrument
panel have gone out.
Faults:
Faults are declared to be either present or stored (depending on whether they appeared in a certain situation and
have disappeared since, or whether they remain but are not diagnosed within the current context).
The present or stored state of faults should be taken into consideration when the diagnostic tool is used after the
+ after ignition feed (without acting on the system components).
Deal with present faults according to the procedure specified in the Interpretation of faults section.
For stored faults, note the faults displayed and follow the instructions in the "Notes" section.
If the fault is confirmed when the instructions in the Notes section are applied, the fault is present. In this case, deal
with the fault
If the fault is not confirmed, carry out basic checks. Check:
– the electrical lines which correspond to the fault,
– the connectors for these lines (for oxidation, bent pins, etc.),
– - the resistance of the faulty component,
– the condition of the wires (melted or cut insulation, wear).
or use the fault finding procedure to check the circuit of the faulty component.
Conformity check
The conformity check is designed to check the states and parameters which do not display any faults on the
diagnostic tool when inconsistent. This phase therefore:
– diagnosis of faults that do not have a fault display, and which may correspond to a customer complaint.
– checks that the system is operating correctly and that there is no risk of a fault reappearing after repairs.
This section gives the fault finding procedures for states and parameters and the conditions for checking them.
If a state is not behaving normally or a parameter is outside permitted tolerance values, you should consult the
corresponding fault finding page.
Customer complaints – Fault finding charts
If the diagnostic tool check is correct, but the customer complaint persists, it should be dealt with according to the
customer complaint.IMPORTANT
The left-hand and right-hand Xenon bulb computers are powered when the dipped headlights are lit. Fault finding
procedures can only be carried out on them after the ignition has been switched on in fault finding mode (+ after
ignition imposed) and the dipped headlights are on.
A synopsis of the general procedure to follow is provided on the following
page in the form of a logic flow chart.
ACU4 Vdiag04 J84 1.0

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Introduction
88C
88C - 5V3 MR-372-J84-88C000$010.mif
AIRBAG ACU4
Vdiag: 04
All faults requiring replacement of a computer for thorough fault finding with the appropriate tools. The diagnostic
sheet must be filled out during the process and indicate the findings for the warranty refund.
6. SAFETY INSTRUCTIONS
All work on components requires obeying safety rules to prevent physical damage or human injury:
– Make sure the battery is properly charged to avoid damaging the computers with a low charge.
During operations on the airbag/seat belt pretensioner systems it is vital that you lock the computer using
the diagnostic tool to prevent any risk of accidental triggering (all the ignition lines will be inhibited). The
locked mode is signalled when the Instrument panel warning light comes on.
If it is impossible to connect the fault-finding tool, switch off the ignition, remove the system power fuse,
and wait at least 2 seconds for the reserve power capacity to discharge.
Never measure the airbag or pretensioner trigger lines with any device other than XRBAG or CLIP's "Airbag
and pretensioner wiring harness check".
Before using a dummy ignition module, ensure that its resistance is between 1.8 and 2.5 ohms.
While working, make sure the computer power supply does not drop below 10 V. WARNING!
5. FAULT FINDING LOG
WARNING:
A properly documented diagnostic sheet is required for all monitored part (computer-type)
reimbursements or Techline calls.
IT IS THEREFORE COMPULSORY TO FILL OUT A FAULT FINDING SHEET EVERY
TIME
A FAULT FINDING OPERATION IS PERFORMED.
WARNING
Airbag and pretensioner destruction and disposal is subject to national legislation.
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AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Introduction
88C - 7
88C
V3 MR-372-J84-88C000$010.mif
SYSTEM CONFIGURATION DIAGRAM (REAR section)
AIRBAG ACU4
Vdiag: 04
ACU4 Vdiag04 J84 1.0
Correct insulation value: display ≥ 100.h or 9999
flashing. AR
A
B
C
D
E
G
H
ITo rear wiring
Central unit
Driver’s seat
Front passenger
seat
Buckle
pretensioner
Driver's front
airbag ignition
module
Passenger's front
airbag ignition
module
Front side airbag
ignition module
Lap belt
pretensioner or
seat cushion
airbagJ/K
L/M
N/O
CT
PCurtain airbag
ignition modules
Rear side airbag
ignition modules
Rear seat belt
retractors
Rotary switch
+ 12 V / earth
Warning light /
Fault finding lines
Impact sensors/
Impact information
Passenger airbag
lock switchFRONT AIRBAGS
Measuring
pointCorrect value
DriverC0, C2 and
C41.8 to 6.2Ω
PassengerC0 and C4 1.8 to 4 Ω
SIDE AIRBAGS AND
PRETENSIONERS
Measuring
pointCorrect value
C0, C1 and
C31.8 to 4 Ω

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - System operation
88C - 9
88C
V3 MR-372-J84-88C000$020.mif
AIRBAG ACU4
Vdiag: 04
AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - System operation
PASSIVE SAFETY EQUIPMENT
The MEGANE II has equipment also found on the LAGUNA II and VEL SATIS, namely:
– Front seat chest side airbag.
– Front seat type BXX double pretensioner.
– Driver's seat position sensor for adaptive airbag.
– Three-point rear centre seat belt.
– Front and rear Isofix mountings.
INNOVATIONS:
– Passenger airbag inhibition switch
– Anti-skid airbag in the seat along with a buckle pretensioner on the
front seat in type CMXX MEGANE II.
In the text, this airbag is referred to as the:
SEAT-CUSHION AIRBAG/DRIVER'S SEAT LAP BELT.
Via the same trigger line, the ACU 4 Vdiag 04 computer controls either the seat-cushion (anti-
skid) airbag or the driver's seat lap belt pretensioner:
The configuration for type B is: Driver's seat lap belt pretensioner.
The configuration for type C is: Driver's seat-cushion airbag.
Both features are never found on the same vehicle because they use the same ignition
line.
ACU4 Vdiag04 J84 1.0
MR-372-J84-88C000$020.mif

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Computer track allocation
88C - 10
88C
V3 MR-372-J84-88C000$030.mif
AIRBAG ACU4
Vdiag: 04
AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Computer track allocation
AIRBAG COMPUTER
22-track connector:
64-track connector:Track Description Track Description
1
2
3
4
5
6
7
8
9
10
11+ Passenger front airbag volume 2
+ Passenger front airbag volume 1
+ Driver's front airbag volume 1
+ Driver's front airbag volume 2
Not used
Not used
+ After ignition
Not used
Not used
CAN L
CAN H12
13
14
15
16
17
18
19
20
21
22- Passenger front airbag volume 2
- Passenger front airbag volume 1
- Driver's front airbag volume 1
- Driver's front airbag volume 2
Not used
Not used
Electrical earth
Not used
Not used
+ Passenger airbag inhibition switch
+ Passenger airbag inhibition switch
Track Description Track Description
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32+ Buckle pretensioner: driver
- Buckle pretensioner: driver
+ Lap belt pretensioner: driver
+ Lap belt pretensioner: driver
Not used
Not used
Not used
Not used
- Driver's seat position sensor
+ Driver's seat position sensor
+ Driver's seat belt buckle contact
- Driver's seat belt buckle contact
Not used
Not used
+ Driver's front chest side airbag
- Driver's front chest side airbag
+ Driver's side curtain airbag
+ Driver's side curtain airbag
+ Driver's rear seat belt retractor
- Driver's rear seat belt retractor
Not used
Not used
Not used
Not used
Not used
Not used
+ Driver's side lateral impact sensor
- Driver's side lateral impact sensor
+ Rear chest side airbag driver's side
- Rear chest side airbag driver's side
Not used
Not used33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64Not used
Not used
Not used
Not used
+ Buckle pretensioner: passenger
- Buckle pretensioner: passenger
+ Lap belt pretensioner: passenger
- Lap belt pretensioner: passenger
+ Rear passenger seat belt retractor
+ Rear passenger seat belt retractor
+ Passenger's front chest side airbag
- Passenger's front chest side airbag
+ Passenger side curtain airbag
-
Passenger side curtain airbag
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
Not used
+ Passenger's rear chest side airbag
- Passenger's rear chest side airbag
Not used
Not used
+ Passenger side lateral impact sensor
- Passenger side lateral impact sensor
Not used
Not used
ACU4 Vdiag04 J84 1.0
MR-372-J84-88C000$030.mif

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding – Replacement of components
88C-12
88C
V3 MR-372-J84-88C000$040.mif
AIRBAG ACU4
VDIAG No.: 04
AIRBAG - SEAT BELT PRETENSIONERS
Fault finding – Replacement of components
REPLACING THE AIRBAG COMPUTER
BEFORE REPLACING ANY COMPUTER, YOU ARE REQUIRED TO CONTACT YOUR
TECHLINE.
So that the failure of the returned computer can be analyzed, the use of command RZ001
"erase fault memory" when DF001 "Computer" is present or stored is officially prohibited.
The airbag computers are sold in locked mode to avoid all risk of accidental triggering (all ignition lines are
inhibited).
The locked mode is signalled when the airbag fault warning indicator lights up on the instrument panel.
Follow this procedure to replace an airbag computer:
– Ensure that the ignition is switched off.
– Replace the computer.
– Modify the computer configuration if necessary.
– Enter the VIN into the computer with diagnostic tool command VP010 Write VIN.
– Switch off the ignition.
– Carry out a check using the diagnostic tool.
– Enter the After Sales operation date with diagnostic tool command VP008 Write last After Sales operation
date.
– Unlock the computer only if no faults are indicated by the diagnostic tool.
After an ACU4 computer has been replaced with a RC5 computer, it is also necessary to replace the impact
sensors. The ACU4 sensors are incompatible with the RC5 computer.
Note:
After the airbag computer is replaced, if the engine no longer starts, restore the injection operation by applying the
following procedure:
– Run command RZ001 to clear the faults from the injection computer memory (even if no present or stored faults
are declared).
– Switch off the ignition and wait for loss of dialogue with the injection computer.
– Drive for 1 minute at a speed greater than 21 mph (35 km/h) to restore the operation of the steering column lock.
ACU4 Vdiag04 J84 1.0

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Interpretation of faults
88C-20
88C
V3 MR-372-J84-88C000$071.mif
AIRBAG ACU4
VDIAG No.: 04
DF002
PRESENT
COMPUTER SUPPLY VOLTAGE
1.DEF: Micro-cut
2.DEF: Values beyond tolerance
NOTESSpecial notes: Use the 22-track adapter (Elé. 1685 when working on the computer
connector (cable 1).
Carry out the operations necessary to obtain the correct voltage supply to the computer: 10.5 V ± 0.1 < correct
voltage < 16 V ± 0.1.
– Check the battery charge.
– Check the charging circuit.
– Check the tightness and the condition of the battery terminals.
– Check the computer earth.
– Check the condition of the computer + locking connections.
AFTER REPAIRClear the computer memory then switch off the ignition.
Carry out the check again using the diagnostic tool and, if there are no faults, unlock
the computer.
ACU4 Vdiag04 J84 1.0

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Interpretation of faults
88C-21
88C
V3 MR-372-J84-88C000$071.mif
AIRBAG ACU4
VDIAG No.: 04
DF010
PRESENT
FAULT WARNING LIGHT CIRCUIT
1.DEF: External diagnostics (instrument panel signal)
2.DEF: Consistency (dashboard indicator light state signal / airbag request)
NOTESSpecial notes: none.
Apply the fault finding procedure relevant to this fault in the instrument panel fault finding information section.
AFTER REPAIRClear the computer memory then switch off the ignition.
Carry out the check again using the diagnostic tool and, if there are no faults, unlock
the computer.
ACU4 Vdiag04 J84 1.0

AIRBAG - SEAT BELT PRETENSIONERS
Fault finding - Interpretation of faults
88C-22
88C
V3 MR-372-J84-88C000$071.mif
AIRBAG ACU4
VDIAG No.: 04
DF028
PRESENT
PASSENGER AIRBAG STATUS INDICATOR LIGHT CIRCUIT
1.DEF: External diagnostics (instrument panel signal)
2.DEF: Consistency (dashboard indicator light state signal / airbag request)
NOTESSpecial notes: none.
Apply the fault finding procedure relevant to this fault in the instrument panel fault finding information section.
AFTER REPAIRClear the computer memory then switch off the ignition.
Carry out the check again using the diagnostic tool and, if there are no faults, unlock
the computer.
ACU4 Vdiag04 J84 1.0