Page 6 of 64
ANTI-LOCK BRAKING SYSTEM
Fault finding - Introduction
38C
38C - 6V2 MR-372-J84-38C000$066_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0F
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 ADVICE
Safety rules must be observed during any work on a component to prevent any damage or injury:
–make sure that the battery is properly charged to avoid damaging the computers with a low load,
–use the appropriate 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). IMPORTANT!IMPORTANT
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.
ABS 8.0X84 4.0
Page 7 of 64
ANTI-LOCK BRAKING SYSTEM
Fault finding - System operation
38C
38C - 7V2 MR-372-J84-38C000$132_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0FANTI-LOCK BRAKING SYSTEM
Fault finding - System operation
The main functions of ABS on this vehicle are the electronic balancing of front and rear braking by controlling rear
wheel slip and preventing the brakes from locking by controlling the slipping of all four wheels.
The system also supplies the other computers with information on the vehicle speed via a wire connection for the
discharge bulbs, the radio 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 via the multiplex network
to ask it to switch on the hazard warning lights (depending on the law in the relevant country).
Fault finding warning light illumination strategy for Mégane II ph1 and Scénic II ph 1
Instrument panel warning lightInstrument panel message
Meaning
MEGANE II SCENIC II
Brake faultsABS SERVICE STOPNo message"Brake
fault"Electronic brake
distribution and ABS
functions inoperative.
ABS SERVICENo messageCheck the
ABSABS function
inoperative.
Brake faults
flashing at
2 HzABS flashing
at 2 HzNo messageNo
messageABS computer is in
fault finding mode.
ABS flashing
at 8 HzNo messageNo
messageTachometric index not
programmed.
NOTE:
The STOP warning light is always accompanied by a single audible warning (1 beep).
ABS 8.0X84 4.0
MR-372-J84-38C000$132_eng.mif
Page 8 of 64
ANTI-LOCK BRAKING SYSTEM
Fault finding - System operation
38C
38C - 8V2 MR-372-J84-38C000$132_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0F
Fault finding warning light illumination strategy for Mégane II ph 2 and Scénic II ph 2
Instrument panel warning lightInstrument panel message
Meaning
MEGANE II
PH2SCENIC II
PH2
Brake faultsABS SERVICE STOPBraking faultElectronic brake
distribution and ABS
functions inoperative.
ABS SERVICECheck ABSABS function
inoperative.
Brake faults
flashing at
2 HzABS flashing
at 2 HzNo messageABS computer is in
fault finding mode.
ABS flashing
at 8 HzNo messageTachometric index not
programmed.
Vehicle speed at
initialisation not
programmed.
Tachometric index and
vehicle speed at
initialisation not
programmed.
Brake faultsABS flashing
at 8 HzSTOPNo messageVehicle parameters not
programmed.
Vehicle parameters
and tachometric index
not programmed.
Vehicle parameters
and vehicle speed at
initialisation not
programmed.
Vehicle parameters
and tachometric index
and vehicle speed at
initialisation not
programmed.
NOTE:
The STOP warning light is always accompanied by a single audible warning (1 beep).
ABS 8.0X84 4.0
Page 11 of 64
ANTI-LOCK BRAKING SYSTEM
Fault finding - Fault summary table38C
38C - 11V2 MR-372-J84-38C000$330_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0FANTI-LOCK BRAKING SYSTEM
Fault finding - Fault summary table
Tool fault Associated DTC Diagnostic tool title
DF001 50CCComputer supply
DF006 501FFront left-hand wheel speed sensor circuit
DF007 503FRear left-hand wheel speed sensor circuit
DF017 50C3Computer
DF020 50C3Tachometric index programming
DF026 500FFront right-hand wheel speed sensor circuit
DF027 502FRear right-hand wheel speed sensor circuit
DF055 50C3Vehicle parameter programming
DF063 5046Wheel speed inconsistency
DF066 5180No injection multiplex signal
DF090 5041Front right-hand wheel target
DF091 5042Front left-hand wheel target
DF092 5043Rear right-hand wheel target
DF093 5044Rear left-hand wheel target
DF152 50E6Multiplex network
DF153 50C3Multiplex network
DF186 5182No instrument panel multiplex signal
DF188 50C6Brake switch circuit
DF193 5180Invalid injection multiplex signals
ABS 8.0X84 4.0
MR-372-J84-38C000$330_eng.mif
Page 41 of 64
ANTI-LOCK BRAKING SYSTEM
Fault finding - Interpretation of faults
38C
38C - 41V2 MR-372-J84-38C000$396_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0F
DF188
PRESENT
OR
STOREDBRAKE LIGHT SWITCH CIRCUIT
NOTESSpecial notes:
This fault does not cause illumination of any warning lights, nor does it generate any
fault message.
Conditions for applying the fault finding procedure to stored faults:
Clear the stored fault, carry out a road test at a speed of > 37 mph (60 km/h) and test
the brakes using ABS.
Check the conformity of the brake light bulbs.
Using the diagnostic tool, check on the statuses screen that ET017 Brake pedal displays the pressed and released
positions of the brake pedal correctly.
If the correct pedal position is not displayed, use the interpretation of ET017.
If the fault is still present, contact the Techline.
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
ABS8.0_V0C_DF188 /ABS8.0_V0D_DF188/ABS8.0_V0E_DF188/ABS8.0_V0F_DF188 ABS 8.0X84 4.0
Page 43 of 64
ANTI-LOCK BRAKING SYSTEM
Fault finding - Conformity check
38C
38C - 43V2 MR-372-J84-38C000$528_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0FANTI-LOCK BRAKING SYSTEM
Fault finding - Conformity check
NOTESOnly carry out this conformity check after a complete check using the diagnostic
tool.
Order FunctionParameter or Status
checked or Action Display and Notes Fault finding
1Diagnostic tool
dialogueBOSCH ABS 8.0Apply Fault Finding
Chart 1
2Computer
configurationPR030:Tachometric
indexMake sure the index
entered matches the
vehicle's tyres (see
Replacing
components)None
3Vehicle
parameter
readingPR063:Vehicle
parametersEnsure that the
parameters correspond
to the vehicle
undergoing fault finding.See Configurations and
Programming (VP004)
4Brake pedal not
depressed
detectionET017:Brake pedalReleased status
confirmed, brake pedal
not depressedIn the event of a fault,
apply interpretation of
ET017.
5Depressed
brake pedal
detectionET017:Brake pedal"Depressed" status
confirmed; brake pedal
fully depressedIn the event of a fault,
apply interpretation of
ET017.
6Vehicle speed at
initialisationPR020:Vehicle speed at
initialisationCheck that the value is
correct according to the
information in the Help
sectionIn the event of a fault,
apply parameter VP032
Vehicle speed at
initialisation.
ABS8.0_V0C_CCONF/ABS8.0_V0D_CCONF/ ABS8.0_V0E_CCONF/ABS8.0_V0F_CCONF ABS 8.0X84 4.0
MR-372-J84-38C000$528_eng.mif
Page 44 of 64
ANTI-LOCK BRAKING SYSTEM
38C
38C - 44V2 MR-372-J84-38C000$594_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0FANTI-LOCK BRAKING SYSTEM
Fault finding - List of Statuses and parameters
Tool status Diagnostic tool title
ET017Brake pedal
Tool parameter Diagnostic tool title
PR001Front right-hand wheel speed
PR002Front left-hand wheel speed
PR003Rear right-hand wheel speed
PR004Rear left-hand wheel speed
PR005Computer feed voltage
PR020Vehicle speed at initialisation
PR030Tachometric index
PR038Vehicle speed
PR063Vehicle parameters
ABS 8.0X84 4.0
MR-372-J84-38C000$594_eng.mif
Page 45 of 64
ANTI-LOCK BRAKING SYSTEM
Fault finding - Interpretation of statuses
38C
38C - 45V2 MR-372-J84-38C000$660_eng.mif
BOSCH ABS 8.0
Vdiag No.: 0C, 0D, 0E, 0FANTI-LOCK BRAKING SYSTEM
Fault finding - Interpretation of statuses
ET017
BRAKE PEDAL
NOTESSpecial notes:
Carry out the checks only if the "pressed" and "released" statuses are not
consistent with the pedal position.
STATUS IS "RELEASED" WITH BRAKE PEDAL PRESSED.
If brake lights operate:
–Check the continuity of the connection between track 1 of the brake light switch connector and track 20 of the
computer connector.
If the brake lights do not operate:
–Check the condition and fitting of the brake light switch and brake lights fuse.
–Remove the brake light switch and check that it is operating correctly:
Continuity between tracks Insulation between tracks
Switch pressed
(Brake pedal released)3 and 4 1 and 2
Switch released
(Brake pedal depressed)1 and 2 3 and 4
Replace the switch if necessary.
Check for + after ignition feed on tracks 2 and 4 on the brake light switch connector.
AFTER REPAIRClear the computer fault memory.
Carry out a road test followed by another check with the diagnostic tool.
ABS8.0_V0C_ET017/ ABS8.0_V0D_ET017/ABS8.0_V0E_ET017/ABS8.0_V0F_ET017 ABS 8.0X84 4.0
MR-372-J84-38C000$660_eng.mif
