2009 RENAULT TWINGO sensor

38C-67
MR-413-X44-38C000$940_eng.mif
V1
ANTI-LOCK BRAKING SYSTEM
Fault finding - Fault Finding Chart
MK70 ABS
Vdiag No: 04
38C
ALP 2 Locking of one or more wheels
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
Check the conformity of the mechanical components.
NOTESLocking of wheels on a vehicle fitted with ABS or squealing of the tyres, which feels
like locking to the customer, may be linked to normal operation of the system and
should not always be considered a fault:
–Locking is allowed below 4 mph (6 km/h) (system regulation will not be activated).
–Braking with ABS system regulation on very poor roads (significant grating).
However, if the wheel(s) is/are actually locking, lift the vehicle in order to be able to rotate the wheels and check:
–Possible inversion when connecting the speed sensors.
Using parameters PR001, PR002, PR003 and PR004, rotate the wheels slowly and check the consistency of the
results obtained.
If the value measured is zero, rotate the other wheels to confirm an electrical inversion of the sensors and repair
the wiring harness.
–Possible inversion of pipes on the hydraulic unit.
Use commands Front left wheel solenoid valves, Front right wheel solenoid valves, Rear left wheel solenoid
valves and Rear right wheel solenoid valves while depressing the brake pedal and check for 10 unlocking/locking
cycles on the wheel concerned (see Dealing with command modes). If the 10 cycles are not carried out on the
wheel tested (wheel remains locked), check whether they are carried out on another wheel (confirmation of a
reversal: repair).
If the 10 cycles are not detected on a wheel and the pipes have not been reversed, change the hydraulic unit.
Check that the sensor holder does not rotate (depending on fitting).
Check the quality of the mounting of the wheel speed sensors (correct clipping for the front wheels).
Check the conformity of the targets: condition, number of teeth = 48 (using command SC001 Check target
teeth).
If the fault is still present after these checks, replace the hydraulic unit.
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
ABS_V04_ALP2

38C-68
MR-413-X44-38C000$940_eng.mif
V1
MK70 ABS
Vdiag No: 04ANTI-LOCK BRAKING SYSTEM
Fault finding - Fault Finding Chart38C
ALP 3 Pull
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
Check the conformity of the mechanical components.
Disconnect one wheel speed sensor.
Start the engine and ensure that only the ABS
system fault warning light comes on. Do not drive
the vehicle if the brake fault warning light is also lit,
as the "EBD" (brake limiter) function is no longer
ensured.
Carry out a road test with the ABS thus out of order.
Is the customer complaint still present under
these conditions?
NO
Raise the vehicle so that you can rotate the wheels
and check:
–Possible inversion when connecting the speed
sensors.
–Possible inversion of pipes on the hydraulic unit.
For these two tests, refer to and apply the
procedures described in ALP 2.
Check the condition and conformity of the ABS
targets.
If necessary, replace the targets.
If the fault is still present replace the hydraulic unit.
YESIf the brake pedal travel is relatively long,
bleed the brake circuit.
If the travel is normal, check the tyre
pressures, the front axle, or for any leaks
in the circuit.
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
ABS_V04_ALP3

38C-69
MR-413-X44-38C000$940_eng.mif
V1
MK70 ABS
Vdiag No: 04ANTI-LOCK BRAKING SYSTEM
Fault finding - Fault Finding Chart38C
ALP 4 Drift
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
Disconnect one wheel speed sensor.
Start the engine and ensure that only the ABS
system fault warning light comes on. Do not drive
the vehicle if the brake fault warning light is also lit,
as the "EBD" (brake limiter) function is no longer
ensured.
Carry out a road test with the ABS thus out of order.
Is the customer complaint still present under
these conditions?
NO
Normal behaviour linked to the system operation
during the regulation phase, mainly on surfaces with
uneven grip or which are poorly laid.
YESRoad holding fault not related to the ABS.
Check the condition of the brake linings
and that they are to specification and
check the tyre pressures, the front axle,
etc.
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
ABS_V04_ALP4

38C-70
MR-413-X44-38C000$940_eng.mif
V1
ANTI-LOCK BRAKING SYSTEM
Fault finding - Fault Finding Chart
MK70 ABS
Vdiag No: 04
38C
ALP 5Unexpected ABS operation at low speed and with
slight pedal pressure
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
IMPORTANT: ABS regulation is sensitive on slippery surfaces (ice, wet cobbled
streets, etc.).
Check the conformity of the mechanical components.
Brake pedal vibrations may be felt which are connected to the system behaviour in particular situations:
–Crossing speed bumps.
–Tight cornering with lifting of the inside rear wheel.
These vibrations may be linked simply to "EBD" (brake limiter) activation, when the pressure on the rear axle is
limited.
If the fault relates to something else, check the speed sensor connectors (micro-breaks) as well as the targets.
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
ABS_V04_ALP5