2009 RENAULT TWINGO traction control

38C-11V3 MR-413-X44-38C050$030.mif
38C
Bosch 8.1 ESP
Vdiag No.: 05
Number Description
1Computer/hydraulic unit assembly
2Steering wheel angle
3Torque setpoint on the engine management computer
4Sequential gearbox operating phase (if fitted)
5Instrument panel
6Diagnostic socket
7 UCH
8Vehicle speed wire
9Brake light control relay
10Combined sensor: lateral acceleration and yaw speed
11Brake disc with instrumented bearing target
12Wheel speed sensor
13Battery
14Traction control deactivation button (Only on RS version)
15Brake switch
Electric circuit
Hydraulic circuit
Private multiplex line
Vehicle multiplex line
ANTI-LOCK BRAKING SYSTEM
Fault finding – Functional diagram

38C-12V3 MR-413-X44-38C050$040.mif
38C
Bosch 8.1 ESP
Vdiag No.: 05
EBD (electronic braking distribution):
The electronic braking distribution unit 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. Its purpose is to prevent the drive wheels from spinning
excessively when lifting off the accelerator or changing down a gear on a low grip surface, by requesting the engine
management to regulate the driving torque of the engine (resisting torque compensation) to "relaunch" the wheels.
ASR (wheel traction control):
This function keeps the drive wheels from slipping during starting or acceleration.
The system brakes the wheel in a slippage situation to maintain full traction.
ESP: Electronic stability program:
The ESP guarantees within physical limits the dynamic stability of the vehicle by checking and correcting oversteer.
In any case, the ESP system does not intervene in place of the driver. Using data from the steering wheel, it merely
makes vehicle handling truer to the driver's intention.
CDC (Dynamic Driving Control):
The Dynamic Driving Control guarantees vehicle steerability within physical limits by checking and correcting
understeer.
The Dynamic Driving Control is an advancement of the ESP system and has same objective: to maintain vehicle
control in all operating situations.
The ESP computer supplies the other computers with information on the vehicle speed via a wire connection for the
radio, the power-assisted steering and the electric sunroof, and via the multiplex network for the other computers.
The ESP computer also supplies the multiplex network with the odometry for the instrument panel and navigation
system.
If heavy braking produces very rapid deceleration, the ESP computer issues a request to the UCH (passenger
compartment connection unit) via the multiplex network asking it to switch on the hazard warning lights (depending
on the law in the relevant country).
ANTI-LOCK BRAKING SYSTEM
Fault finding – Features

38C-14V3 MR-413-X44-38C050$060.mif
38C
Bosch 8.1 ESP
Vdiag No.: 05
Fault finding warning lights programming
Instrument panel warning light Meaning
Brake faultsABS system ESP SERVICE STOP"Brake limiter", ABS, and
ESP functions not working
ABS system ESP SERVICEESP and ABS functions not
working, "brake limiter"
operational
ESP SERVICEESP function not working, ABS
and "brake limiter"
operational
ESP
"Wheel traction control"
function deactivated by fault
finding orESPmomentarily
disco nnected a fter the battery is
disconnected
Brake faults
flashing
at 2 H z (slowly)ABS flashing
at 2 Hz
(slowly)ESP flashing
at 2 Hz (slowly)ESP computer in fault finding
mode
ESP flashing
at 8 Hz
(quickly)ESP or "wheel traction control"
or "anti-lock brake system on
engine torque control" active
ABS flashing
at 8 Hz
(quickly)Tachometric index not
programmed
Brake faults ABS systemESP flashing
at 8 Hz
(quickly)SERVICE STOPVehicle variant not
programmed
Brake faultsABS flashing
at 8 Hz
(quickly)ESP flashing
at 8 Hz
(quickly)STOPVehicle option and tachometric
index not programmed
Note:
The STOP warning light is always accompanied by a single audible warning (1 beep).
ANTI-LOCK BRAKING SYSTEM
Fault finding – Defect and safe modes