Page 41 of 59
POWER-ASSISTED STEERING
Fault finding – Interpretation of parameters
36B
36B-41V5 MR-372-J84-36B000$792_fra.mif
EPAS
Vdiag no.: 05, 09,
0DPOWER-ASSISTED STEERING
Fault finding – Interpretation of parameters
PR001
TORQUE APPLIED TO THE STEERING WHEEL
NOTESNone.
This parameter indicates the torque applied by the driver to the steering column. It is positive when the steering
wheel is turned to the right and negative when it is turned to the left.
If the parameter does not conform with the values indicated in the Conformity check, refer to the interpretation of
fault DF054 Torque sensor.
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_PR001/DAE_V09_PR001/DAE_V0D_PR001
MR-372-J84-36B000$792_fra.mif
Page 42 of 59
POWER-ASSISTED STEERING
Fault finding – Interpretation of parameters
36B
36B-42V5 MR-372-J84-36B000$792_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
PR006
STEERING MOTOR TORQUE SETPOINT
NOTESNone.
This parameter indicates the torque setpoint sent by the EPAS computer to the steering motor. It is positive when
the steering wheel is turned to the right and negative when it is turned to the left.
If the parameter is not in conformity with the values shown in the Conformity check, refer to the interpretation of
fault DF035 Variable power-assisted steering motor.
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_PR006/DAE_V09_PR006/DAE_V0D_PR006
Page 43 of 59
POWER-ASSISTED STEERING
Fault finding – Interpretation of parameters
36B
36B-43V5 MR-372-J84-36B000$792_fra.mif
EPAS
Vdiag no.: 05, 09
PR007
STEERING WHEEL ANGLE DRIFT COMPENSATION
NOTESNone.
This parameter shows the correction of the angle value, implemented automatically by the EPAS computer. When
driving, if the steering wheel angle in the straight-ahead driving position is not 0˚, this parameter varies (offset from
the steering wheel angle value).
If the value of the parameter is different to 0 d˚ (± 10 d˚), check the value of parameter PR121 Steering wheel
angle with straight wheels, if PR121 > ± 10 d˚ program the steering wheel angle using command VP004 Steering
wheel sensor programming (see Configuration and programming, section C).
If PR121 < ± 10 d˚ and the vehicle is fitted with ESP, place the vehicle on a geometry test bench (front axle test
bench).. Position the vehicle wheels in the straight line driving position (steering centre point).
Program the steering wheel angle using command VP004 Steering wheel angle sensor programming (see
Configuration and programming).
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_PR007/DAE_V09_PR007
Page 44 of 59
POWER-ASSISTED STEERING
Fault finding – Interpretation of parameters
36B
36B-44V5 MR-372-J84-36B000$792_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
PR012
PR013
CURRENT ABSORBED BY THE MOTOR
SETPOINT FOR CURRENT ABSORBED BY THE MOTOR
NOTESNone.
Parameter PR013 indicates the electrical power (strength) setpoint sent by the EPAS computer to the steering
motor as a function of the torque applied to the steering wheel.
Parameter PR012 indicates the electrical power actually consumed by the EPAS motors.
These two parameters are positive when the steering wheel is turned to the right and negative when turned to the
left.
The value of parameter PR013 Rated motor power should be almost equal to the value of parameter PR012
Power absorbed by the motor.
If the parameters are not in conformity with the values shown in the Conformity check, or if they are not equal,
refer to the interpretation of fault DF035 Variable power steering motor.
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_PR012/DAE_V05_PR013/DAE_V09_PR012 /DAE_V09_PR013/DAE_V0D_PR012/DAE_V0D_PR013
Page 45 of 59
POWER-ASSISTED STEERING
Fault finding – Interpretation of parameters
36B
36B-45V5 MR-372-J84-36B000$792_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
PR014
LEVEL OF ASSISTANCE AVAILABLE
NOTESNone.
In normal operation, this parameter shows the steering assistance value which depends on the level of motor
protection.
When the user holds the steering at full lock for more than 0.5 seconds, assistance drops to 52%.
This parameter can fall below 100% when the EPAS system is heated during repeated manoeuvres; this stores
fault DF001 Motor thermal protection if the heating lasts longer than 1 minute.
Note:
The level of assistance can be degraded according to system faults (see Faults summary table).
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_PR014/DAE_V09_PR014/DAE_V0D_PR014
Page 46 of 59
POWER-ASSISTED STEERING
Fault finding – Interpretation of parameters
36B
36B-46V5 MR-372-J84-36B000$792_fra.mif
EPAS
Vdiag no.: 05, 09
PR121
STEERING WHEEL ANGLE
NOTESNone.
This parameter shows the steering wheel position in relation to the programmed zero (performed by command
VP004 "Steering wheel angle sensor programming").
This parameter is positive to the right and negative to the left.
If the angle remains at 3696˚, either:
–the steering wheel angle programming has not been carried out (ET020 Steering wheel angle programming
is STATUS 1 or STATUS 2),
–or the steering wheel is outside the range ± 120 d˚ (ET020 Steering wheel angle programming is STATUS 3),
when the APC is switched on, therefore the angle is valid; the angle is STATUS 4 only if the steering wheel is
within the range ± 120 d˚. As the sensor's coverage is not complete, it needs to come within this zone to detect
its position.
Thus, when the APC is switched on, if the steering wheel is not within the range ± 120 d˚ then the angle is invalid
(ET020 Steering wheel angle programming is STATUS 3). Simply rotating the steering wheel so that it is in the
± 120 d˚ range will allow a valid angle to be found (ET020 Steering wheel angle programming is STATUS 4),
when the EPAS is operating correctly,
–the sensor is faulty DF038 Angle sensor.
If the angle remains at 3696˚, with action on the steering wheel and status ET020 Steering wheel angle
programming is STATUS 4, contact the Techline.
If the parameter does not correspond to the values shown in the Conformity check, place the vehicle on a
geometry test bench (front axle bench). Position the vehicle wheels in the straight line driving position (steering
centre point).
Program the steering wheel angle using command VP004 Steering wheel angle sensor programming (see
Configuration and programming).
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_PR121/DAE_V09_PR121
Page 47 of 59
POWER-ASSISTED STEERING
Fault finding – Customer complaints
36B
36B-47V5 MR-372-J84-36B000$858_fra.mif
EPAS
Vdiag no.: 05, 09,
0DPOWER-ASSISTED STEERING
Fault finding – Customer complaints
NOTESOnly refer to the customer complaints after performing a complete check using the
diagnostic tool.
NO DIALOGUE WITH THE COMPUTER ALP1
LOSS OF VEHICLE ASSISTANCE WITHOUT WARNING ALP2
POOR VEHICLE HANDLINGALP3
THE STEERING WHEEL DOES NOT RETURN BY ITSELF
TO THE CENTRE AT LOW SPEED: STEERING WHEEL
RETURN TO CENTRE POINT INACTIVE (ONLY FOR
VDIAG 05 AND 09)ALP4
UNDER-ASSISTANCE AT LOW SPEED AND OVER-
ASSISTANCE AT HIGH SPEED WITHOUT WARNINGALP5
TOO LITTLE ASSISTANCEALP6
ASSISTANCE AVAILABLE FOR 5 MIN. AFTER
SWITCHING OFF THE IGNITIONALP7
ASSISTANCE AVAILABLE BUT CHECK STEERING
WARNING MESSAGE DISPLAYED AND SERVICE
INDICATOR LIGHT CONTINUOUSLY LITALP8
THE VEHICLE PULLS TO THE RIGHT OR TO THE LEFT ALP9
SERVICE INDICATOR LIGHT AND CHECK STEERING
MESSAGE COME ON STRAIGHT AWAYALP10
STEERING ASSISTANCE IS AVAILABLE WITH IGNITION
ON AND ENGINE STOPPED, WITH NO WARNINGALP11
THE ENGINE DOES NOT START AND THE MESSAGE
"STEERING NOT UNLOCKED" IS DISPLAYED
OR
THE MESSAGE "STEERING NOT UNLOCKED" IS
DISPLAYED AFTER THE IGNITION IS SWITCHED OFFALP12
MR-372-J84-36B000$858_fra.mif
Page 48 of 59
POWER-ASSISTED STEERING
Fault finding – Fault Finding Chart
36B
36B-48V5 MR-372-J84-36B000$924_fra.mif
EPAS
Vdiag no.: 05, 09,
0DPOWER-ASSISTED STEERING
Fault finding – Fault Finding Chart
ALP1 No dialogue with the computer
NOTESNone.
Run fault finding on the multiplex network.
Check the voltage of the vehicle battery (the EPAS system only reacts between 10 V and 18 V).
Repair if necessary.
Try the diagnostic tool on another vehicle.
Check:
–the connection between the diagnostic tool and the diagnostic probe (lead in good condition),
–the connection between the diagnostic sensor and the diagnostic socket (lead in good condition).
Check the condition of the EPAS fuses and their contacts:
80A BP81 Power fuse in the engine fuse box.
5A AP44 + after ignition fuse on the UPC.
Check for the presence of + 12 V battery feed on track 16, and + 12 V after ignition feed on track 1 and an earth
on track 5 and on track 4 of the diagnostic socket.
Repair if necessary.
Disconnect the two EPAS computer connectors.
Check the condition and conformity of the connectors and their clips.
Check the conformity of the electrical supplies (they must be equal to the battery voltage).
Electric Power Assisted Steering Computer Connector:
2-track connector track 1+ battery feed
2-track connector track 2Earth
8-track connector track 8+ After ignition
Repair if necessary.
Check the insulation, continuity and the absence of interference resistance on the wiring harness between
the diagnostic socket and the Electric Power Assisted Steering computer connector.
Electric Power Assisted Steering Computer Connector:
8-track connector track 5 track 14 Diagnostic socket
8-track connector track 7 track 6 Diagnostic socket
Repair if necessary.
If the fault is still present, contact the Techline.
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_ALP1/DAE_V09_ALP1/DAE_V0D_ALP1
MR-372-J84-36B000$924_fra.mif
