2009 RENAULT TWINGO RS brake

38C-6
MR-413-X44-38C000$047_eng.mif
V1
ANTI-LOCK BRAKING SYSTEM
Fault finding - Introduction
MK70 ABS
Vdiag No: 04
38C
Visual inspection of the sealing:
(Only for watertight connectors)
●Check for the seal on the connection (between the 2 parts of the connection).
●Check the seal at the back of the connectors:
–For unit joints (1 for each wire), check that the unit joints are present on each electrical wire and that
they are correctly positioned in the opening (level with the housing). Check that plugs are present on
openings which are not used.
–For a grommet seal (one seal which covers the entire internal surface of the connector), check that
the seal is present.
–For gel seals, check for gel in all of the openings without removing the excess or any protruding
sections (it does not matter if there is gel on the contacts).
–For hotmelt sealing (heat-shrink sheath with glue), check that the sheath has contracted correctly on
the rear of the connectors and electrical wires, and that the hardened glue comes out of the side of
the wire.
●Check that there is no damage to any of the seals (cuts, burns, significant deformation, etc.).
If a fault is detected, repair or replace the wiring (see Technical Note 6015A, Repairing electrical wiring, Wiring:
Precautions for repair)
5. FAULT FINDING LOG
You will always be asked for this log:
–when requesting technical assistance from Techline,
–for approval requests when replacing parts for which approval is mandatory,
–to be attached to monitored parts for which reimbursement is requested. The log is needed for
–warranty reimbursement, and enables better analysis of the parts removed.
6. SAFETY INSTRUCTIONS
Safety rules must be observed during any work on a component to prevent any damage or injury:
–check the battery voltage to avoid incorrect operation of computer functions,
–use the proper tools.
It is forbidden to carry out a road test with the diagnostic tool in dialogue with the ECU because the ABS and
Electronic Brake Distribution functions are deactivated. Braking pressure is identical on both vehicle axles
(risk of a spin under heavy braking).IMPORTANTIMPORTANT
Any fault on a complex system requires thorough fault finding with the appropriate tools. The
FAULT FINDING LOG, which should be completed during the procedure, enables you to keep
track of the procedure which is carried out. It is an essential document when consulting the
manufacturer.
IT IS THEREFORE MANDATORY TO FILL OUT A FAULT FINDING LOG EACH TIME FAULT FINDING IS
CARRIED OUT.

38C-7
MR-413-X44-38C000$094_eng.mif
V1
38C
ANTI-LOCK BRAKING SYSTEM
Fault finding - List and location of components
The computer/hydraulic unit assembly:
●Located to the left of the bulkhead in the engine compartment.
Front wheel sensors:
●Screwed into the stub-axle, each front sensor has an intermediate connector located behind the plastic wheel
arch liner.
Rear wheel sensor intermediate connectors:
●Located in a sealed unit under the vehicle.
Rear wheel sensors:
●Screwed into the rear brake drum flange.
Brake light switch:
●Located on the pedal assembly.
MK70 ABS
Vdiag No: 04
MR-413-X44-38C000$094_eng.mif

38C-8
MR-413-X44-38C000$141_eng.mif
V1
38C
ANTI-LOCK BRAKING SYSTEM
Fault finding - Operating diagram
Number Description
1Computer
2Hydraulic unit (8 solenoid valves)
3Electric power assisted steering
4Instrument panel - engine management
5Passive brake servo
6Brake lights switch
7Diagnostic socket
8Battery
9Wheel speed sensor
10Target
11Brake discs
MK70 ABS
Vdiag No: 04
MR-413-X44-38C000$141_eng.mif

38C-9
MR-413-X44-38C000$188_eng.mif
V1
38C
ANTI-LOCK BRAKING SYSTEM
Fault finding - Function
EBD (electronic braking distribution):
The EBD optimises the brakeforce distribution between the front and rear axles. This function ensures vehicle
stability under braking.
ABS (anti-lock braking system):
The ABS prevents the wheels from locking when braking. This function allows the vehicle to be steered under
braking and ensures vehicle stability under braking.
MSR (engine torque control):
This is a function that enhances the ABS function. It prevents the drive wheels from spinning excessively when lifting
off the accelerator or changing down a gear on a low grip surface, by allowing the engine to regulate the driving
torque of the engine (resisting torque compensation) to "relaunch" the wheels.
The system also supplies the other computers with information on the vehicle speed via a wire connection for the
radio, the power steering and the electric sunroof, and via the multiplex network for the other computers. The ABS
computer supplies the multiplex network with the odometry for the instrument panel and navigation system. If heavy
braking produces very rapid deceleration, the ABS computer sends out a request to the UCH (passenger
compartment connection unit) via the multiplex network to ask it to switch on the hazard warning lights (depending
on the law in the relevant country).
MK70 ABS
Vdiag No: 04
MR-413-X44-38C000$188_eng.mif

38C-10
MR-413-X44-38C000$235_eng.mif
V1
38C
ANTI-LOCK BRAKING SYSTEM
Fault finding - Role of components
Wheel speed sensor:
Gives the speed of each of the vehicle's wheels. The analysis of the right/left-hand speeds makes it possible to
calculate in what direction the vehicle is turning.
Brake lights switch:
Visual indication of the brake pedal position. It makes it possible to tell if the driver is braking or not.
Wire connection (vehicle speed):
The ABS computer is best suited to transmit the vehicle speed to the other computers. To do this, the ABS transmits
the vehicle speed on the CAN network. However, some computers are not connected to the CAN network, this is
why the ABS is fitted with a "vehicle speed" wire output. Fault finding is not run on this connection by the ABS
computer. This enables the consumers of this signal to perform the necessary checks during their own fault finding
procedure, or to check the connection by observing the customer complaint on the consumer (for example, increase
in the volume of the radio if the speed increases, electric power-assisted steering).
MK70 ABS
Vdiag No: 04
MR-413-X44-38C000$235_eng.mif

38C-11
MR-413-X44-38C000$282_eng.mif
V1
38C
ANTI-LOCK BRAKING SYSTEM
Fault finding - Defect and safe modes
Fault finding warning lights programming
Instrument panel warning lightInstrument panel
messageMeaning
Brake faultsABS system STOPNo computer.
ABS flashing
at 8 Hz
(quickly)Tachometric index not
programmed.
ABS flashing
at 8 Hz
(quickly)SERVICETachometric index not
programmed and
versions not
programmed.
Brake faults
flashing at
2 HzABS flashing
at 2 Hz
(slowly)No messageABS computer is in fault
finding mode.
ABS system SERVICE Check the ABS ABS fault.
Brake faultsABS system SERVICE STOP Braking system fault EBD fault.
Note:
The STOP warning light is always accompanied by a single audible warning (1 beep).
MK70 ABS
Vdiag No: 04
MR-413-X44-38C000$282_eng.mif

38C-12
MR-413-X44-38C000$329_eng.mif
V1
38C
ANTI-LOCK BRAKING SYSTEM
Diagnostics - Replacing parts
REPLACING THE COMPUTER
When replacing the computer (see MR411 Mechanical systems, 38C, Brake computer, removal - refitting), apply
the following procedure:
–switch off the ignition,
–replace the computer,
–enter the VIN number using command VP001 "Write VIN",
–configure the tachometric index with command VP007 "Tachometric index",
–configure the vehicle parameters with command VP004 "Vehicle parameters",
–configure the gearbox type fitted to the vehicle with command CF079 "Gearbox type",
–enter the After-Sales date with command VP006 "Enter last After-Sales operation date",
–perform a road test followed by a fault reading to confirm that the system is operating correctly.
MK70 ABS
Vdiag No: 04
MR-413-X44-38C000$329_eng.mif

38C-14
MR-413-X44-38C000$423_eng.mif
V1
38C
ANTI-LOCK BRAKING SYSTEM
Fault finding - Fault summary table
Tool fault Associated DTC Diagnostic tool title
DF00150 Short circuit Computer supply
DF0065015 Front left-hand wheel speed sensor circuit
DF0075035 Rear left-hand wheel speed sensor circuit
DF008501F Front left-hand wheel speed sensor signal
DF009503F Rear left-hand wheel speed sensor signal
DF01050D3 Pump motor circuit
DF01750C3 Computer
DF0205140 Tachometric index programming
DF0265005 Front right-hand wheel speed sensor circuit
DF0275025 Rear right-hand wheel speed sensor circuit
DF028500F Front right-hand wheel speed sensor signal
DF029502F Rear right-hand wheel speed sensor signal
DF0555143 Vehicle parameter programming
DF06650E2 No injection multiplex signal
DF0905041 Front right-hand wheel target
DF0915042 Front left-hand wheel target
DF0925043 Rear right-hand wheel target
DF0935044 Rear left-hand wheel target
DF0965148 Computer internal electronic irregularity
DF09850E4 No UCH multiplex signal
DF1195150 Gearbox type configuration
DF121D11D Torque requested not available
DF15250E6 Multiplex network
DF18850C6 Brake light switch circuit
DF219D132 ABS multiplex signal consistency
DF2295002 Front right-hand wheel speed
DF2305011 Front left-hand wheel speed
DF2315021 Rear right-hand wheel speed
DF2325031 Rear left-hand wheel speed
DF250D117 Engine speed multiplex signal
DF251D118 Effective average torque multiplex signal
DF252D119 Torque request multiplex feedback signal
DF253D120 Recalculated torque multiplex signal
DF254D12F Resisting torque multiplex signal
DF31150E3 No BVR multiplex signal
MK70 ABS
Vdiag No: 04
MR-413-X44-38C000$423_eng.mif