wheel torque RENAULT TWINGO 2009 2.G Chasiss - Power Assisted Steering Workshop Manual

36B-9
MR-413-X44-36B000$201.mif
V2
36B
POWER – ASSISTED STEERING
Fault finding – Role of components
Angle sensor:
This sensor indicates the position of the steering wheel in real time (only for Vdiag 04).
Torque sensor:
This sensor enables the assistance torque to be controlled according to the force applied to the steering wheel by
the driver.
Computer:
This computer calculates the level of steering assistance required according to various parameters, including the
vehicle speed and the steering wheel torque.
Motor:
The motor provides the necessary steering torque assistance according to driver requirements. EPAS
Vdiag No.: 04 - 08
MR-413-X44-36B000$201.mif

36B-11
MR-413-X44-36B000$268.mif
V2
POWER – ASSISTED STEERING
Fault finding – Function
EPAS
Vdiag No.: 04 - 08
36B
GENERAL OPERATION
On this vehicle, the steering system is power-assisted by an electric motor attached to the steering column.
The torque sensor and steering column angle sensor interpret any movement of the steering wheel as it is turned.
Assistance is provided by an electric motor which applies more or less torque to the steering column, in one direction
or the other.
A computer controls this assistance according to several vehicle environment parameters, including the vehicle
speed.
EPAS ALSO OFFERS THE FOLLOWING:
Active recall:
This function is made necessary by the design of the front axle of vehicles with electric power-assisted steering.
It returns the steering wheel to the centre point when driving at low speeds (5 to 20 mph / 8 to 32 km/h) but not when
the vehicle is stationary. This function is normal on hydraulic power-assisted steering vehicles or vehicles without
assistance.
This function cannot be deactivated by the diagnostic tool.
Depending on the operating conditions and the operations performed on the vehicle before switching on the ignition,
the assistance system may take a certain amount of time to be activated after engine starting, for instance after
battery cut-off or switching off the ignition (see Configurations and programming).Note:
When the computer detects a fault, the level of assistance can be modified depending on how serious the fault is.
An incorrect or absent vehicle speed signal results in assistance equal to that provided at 72 mph (120 km/h)
without active return. The EPAS sends a "Steering wheel angle signal" to the ABS/ESP computer.

36B-12
MR-413-X44-36B000$268.mif
V2
POWER – ASSISTED STEERING
Fault finding – Function
EPAS
Vdiag No.: 04 - 08
36B
SIGNALS RECEIVED AND SENT
1Vehicle speed
2Engine speed
3Power supply (permanent +)
4Supply (+ after ignition feed)
5Earth
6Steering wheel angle (Vdiag 04 only)
7Steering wheel torque
8Instrument panel indicator light on
9Diagnostic socket
10 Power-assisted steering computer

36B-16
MR-413-X44-36B000$469.mif
V2
EPAS
Vdiag No.: 04 - 08
36B
DF001
PRESENT
OR
STOREDMOTOR THERMAL PROTECTION
DEF: Operating temperature too high
NOTESConditions for applying the fault finding procedure to stored faults:
Apply this fault finding procedure even if the fault is stored.
Notes:
This fault does not indicate a system failure, but indicates overheating either of the
Electric Power-Assisted Steering (EPAS) motor or of the computer during repeated
manoeuvres.This fault may appear after the steering wheel is moved repeatedly
(parking) and causes a gradual reduction in steering but the fault warning light does
not come on.
Use the diagnostic tool to check the conformity of PR129 Motor power (60 A) and PR130 Motor power (45 A)
(zero in absence of PR001 Torque applied to steering wheel).
Contact the Techline in the event of any nonconformity.
Check the conformity of the computer and steering column (45 or 60 A) in relation to the table below:
Left-hand drive Right-hand drive
Torque sensor wiring harness blue black
Motor wiring45 Agreen black
Motor wiring60 Ablue grey
45 A 60 A
Computer label yellow white
In the event of a nonconformity, consult "RENAULT NET" to repair the vehicle according to the technical vehicle
definition.
Disconnect the battery then allow the electric power-assisted steering to cool down.
Reconnect the battery, clear the faults, start the vehicle and check the operation of the electric power-assisted
steering by turning the steering wheel full lock to the left or right.
The fault should not recur in the next 30 seconds.
If the fault recurs as present or stored, contact the Techline.
AFTER REPAIRDeal with any other faults.
Clear the stored faults.
Check that the EPAS is working.
DAE_V04_DF001 /DAE_V08_DF001
POWER – ASSISTED STEERING
Fault finding – Interpretation of faults

36B-23
MR-413-X44-36B000$469.mif
V2
POWER – ASSISTED STEERING
Fault finding – Interpretation of faults
EPAS
Vdiag No.: 04 - 08
36B
DF039
DF048
DF050
DF054
PRESENT
OR
STOREDTORQUE SENSOR CIRCUIT
TORQUE SENSOR CIRCUIT
TORQUE SENSOR CIRCUIT SIGNAL 2
TORQUE SENSOR
CO.O: Open circuit or short circuit to earth
NOTESConditions for applying the fault finding procedure to stored faults:
The fault is declared present after having started the engine and turned the steering
wheel from lock to lock, then returning it to the centre.
Notes:
This fault causes:
Sudden loss of steering assistance with illumination of the Fault warning light +
STOP + Beep.
Use the Wiring Diagram Technical Note for New Twingo.
With + after ignition feed off, check the connection and condition (possible wiring damage) of connector C and
its clips of component 502.
If the connector is faulty (see Technical Note 6015A, Electrical wiring repair, Wiring: Precautions for repair)
repair the wiring, otherwise replace it.
Visually check the condition of the wiring harness of component 850 (for possible wiring damage).
If the connection or connections are faulty (see Technical Note 6015A, Electrical wiring repair, Wiring:
Precautions for repair), repair the wiring, otherwise replace the steering column.
With the connectors of components 502 and 850 disconnected, check the continuity and insulation of the
following connections between components 502 and 850.
●Connection 109K
●Connection 109M
●Connection 109N
●Connection 109P
If the connection or connections are faulty (see Technical Note 6015A, Electrical wiring repair, Wiring:
Precautions for repair), repair the wiring, otherwise replace the steering column.
With + after ignition feed off, disconnect and check the condition and conformity of connector C and its clips.
Visually check the condition of the torque sensor wiring harness.
In the event of a nonconformity, replace the steering column.
Check the condition of the connection pins of components 502 and 850.
Contact the Techline in the event of any nonconformity.
If the fault is still present, contact the Techline.
AFTER REPAIRDeal with any other faults.
Clear the stored faults.
Check that the EPAS is working.
DAE_V04_DF039/DAE_V08_DF039/DAE_V04_DF048/DAE_V08_DF048
DAE_V04_DF050/DAE_V08_DF050/DAE_V04_DF054/DAE_V08_DF054

36B-25
MR-413-X44-36B000$536.mif
V2
36B
POWER – ASSISTED STEERING
Fault finding – Conformity check
MAIN SCREEN
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool.
Application conditions: ignition on, engine stopped, no movement of
the steering wheel, front wheels set straight ahead.
FunctionParameter or Status
Checked or ActionDisplay and notes Fault finding
Wire informationPR003:Vehicle speedX = 0 mph (km/h)In the event of a fault, apply the
interpretation of parameter
PR003.
PR004: Engine speed0 = rpmIn the event of a fault, apply the
interpretation of parameter
PR004.
AssistancePR001: Torque applied
to the steering
wheel0 Nm (+ 0.2 Nm)In the event of a fault, apply the
interpretation of parameter
PR001.
Steering wheel
angle
(Vdiag 04 only)PR121:Steering wheel
angle- 5˚ < X < 5˚In the event of a fault, apply the
interpretation of parameter
PR121.
EPAS
Vdiag No.: 04 - 08
MR-413-X44-36B000$536.mif
DAE_V04_CCONF/DAE_V08_CCONF

36B-27
MR-413-X44-36B000$536.mif
V2
POWER – ASSISTED STEERING
Fault finding – Conformity check
EPAS
Vdiag No.: 04 - 08
36B
SUB-FUNCTION: ASSISTANCE (CONTINUED)
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool.
Application conditions: ignition on, engine stopped, no movement of the
steering wheel, front wheels set straight ahead.
FunctionParameter or Status
Checked or ActionDisplay and notes Fault finding
AssistancePR001:Torque applied
to the steering
wheel0 Nm (+ 0.2 Nm)In the event of a fault, apply the
interpretation of parameter
PR001.
OutputPR132:Current setpoint
(45 A)0 A
Note: these two
parameters must be
approximately the
same.In the event of a fault, apply the
interpretation of parameters
PR132 and PR130.
PR130:Motor power
(45 A)
PR131:Current setpoint
(60 A)0 A
Note: these two
parameters must be
approximately the
same.In the event of a fault, apply the
interpretation of parameters
PR131 and PR129.
PR129:Motor power
(60 A)

36B-28
MR-413-X44-36B000$536.mif
V2
POWER – ASSISTED STEERING
Fault finding – Conformity check
EPAS
Vdiag No.: 04 - 08
36B
MAIN SCREEN
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool.
Application conditions: engine at idle speed, no movement of the steering
wheel, front wheels straight ahead.
FunctionParameter or Status
Checked or ActionDisplay and notes Fault finding
Wire informationPR003:Vehicle speed0 mphIn the event of a fault, apply the
interpretation of parameter
PR003.
PR004:Engine speed850 +/- 50 rpmIn the event of a fault, apply the
interpretation of parameter
PR004.
Assistance PR001:Torque applied
to the steering
wheel0 Nm (+ 0.2 Nm)In the event of a fault, apply the
interpretation of parameter
PR001.
Steering wheel
angle
(Vdiag 04 only)PR121:Steering wheel
angle- 5˚ < X < 5˚In the event of a fault, apply the
interpretation of parameter
PR121.

36B-30
MR-413-X44-36B000$536.mif
V2
POWER – ASSISTED STEERING
Fault finding – Conformity check
EPAS
Vdiag No.: 04 - 08
36B
SUB-FUNCTION: ASSISTANCE (CONTINUED)
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool.
Application conditions: engine at idle speed, no movement of the steering
wheel, front wheels straight ahead.
FunctionParameter or Status
Checked or ActionDisplay and notes Fault finding
AssistancePR001:Torque applied
to the steering
wheel0 Nm (+ 0.2 Nm)In the event of a fault, apply the
interpretation of parameter
PR001.
OutputPR132: Current setpoint
(45 A)0 A
Note: these two
parameters must be
approximately the
same.In the event of a fault, apply the
interpretation of parameters
PR132 and PR130.
PR130: Motor power (45
A)
PR131: Current setpoint
(60 A)0 A
Note: these two
parameters must be
approximately the
same.In the event of a fault, apply the
interpretation of parameters
PR131 and PR129.
PR129: Motor power (60
A)

36B-35
MR-413-X44-36B00$737.mif
V2
36B
POWER – ASSISTED STEERING
Fault finding – Parameter summary table
Tool parameter Diagnostic tool title
PR001Torque applied to the steering wheel
PR003Vehicle speed
PR004Engine speed
PR121Steering wheel angle
PR129Motor power (60 A)
PR130Motor power (45 A)
PR131Current setpoint (60 A)
PR132Current setpoint (45 A)
EPAS
Vdiag No.: 04 - 08
MR-413-X44-36B00$737.mif