POWER-ASSISTED STEERING
Fault finding – System operation
36B
36B-7V5 MR-372-J84-36B000$132_fra.mif
EPAS
Vdiag no.: 05, 09,
0DPOWER-ASSISTED STEERING
Fault finding – System operation
GENERAL OPERATION
On this vehicle, the steering system is power-assisted by an electric motor attached to the steering column.
The action of the driver is relayed by a torque sensor, which measures the force applied to the steering wheel,
and a steering column angle sensor (steering wheel angle sensor only on Vdiag 05 and 09). Assistance is given
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 used to bring the steering wheel back to the straight-ahead position when driving at low speeds 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.
For Vdiag 05 and 09 (columns with steering wheel angle sensor): this feature is inactive when the steering wheel
angle is not available (ET020 Programming steering wheel angle sensor for STATUS 1, STATUS 2, STATUS 3).
For Vdiag 0D (columns without steering wheel angle sensor): this feature is always inactive.
Lock torque limit:
This function limits the assistance torque when the steering wheel is held at full lock with considerable effort, when
the vehicle is stationary or travelling at a speed less than 3 mph (5 km/h). The purpose of this function is to limit
overheating of the electric power assisted steering motor.
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 60 mph (100 km/h)
without active recall. The EPAS sends a steering wheel angle signal to the ESP computer (if fitted).
MR-372-J84-36B000$132_fra.mif
POWER-ASSISTED STEERING
36B
36B-13V5 MR-372-J84-36B000$396_fra.mif
EPAS
Vdiag no.: 05, 09,
0DPOWER-ASSISTED STEERING
Fault finding – Fault summary table
Tool
faultDiagnostic tool titleAssociated
DTCCustomer complaints and warning light
coming on
DF001Motor thermal protection5614Steering assistance intermittent reduction.
DF002Computer5608Assistance limited to 30% (with SERVICE
warning light + message) or no assistance
(with STOP warning light + message)
depending on the internal fault code.
DF020Computer supply5601Degraded assistance (no warning light or
message) until a loss of assistance below
9 V or above 17 V with STOP indicator light
+ Message.
DF021Steering wheel angle sensor
programming (only for Vdiag 05 and 09)5612Degraded steering wheel recall (with
SERVICE indicator light + message). ESP
fault, if present.
DF023+ after ignition feed5613Assistance gradually cuts out (within
5 minutes). When the ignition is next
switched on there is no steering
assistance.
DF033Multiplex networkD000Inappropriate level of assistance:
SERVICE indicator light + Message.
DF035Variable power assisted steering motor5606Assistance limited to 30% (with SERVICE
warning light + message) or no steering
assistance (with STOP warning light
+ Message).
DF038Angle sensor (only Vdiag 05 and 09) 5605Steering wheel recall degraded
(no warning light or message). ESP fault,
if present.
DF053Computer configuration5602Defect mode assistance (no message
or warning light).
DF054Torque sensor5604Steering assistance loss or absence with
STOP indicator light + Message.
DF055Computer memory5607Degraded assistance (without warning
light or message) or assistance limited to
10% with SERVICE warning light
+ Message.
Risk of ESP fault.
DF057Vehicle speed multiplex signalD200Inappropriate level of assistance:
SERVICE indicator light + Message.
Note:
Warning light/message
SERVICE + "Check steering" or,
STOP + audible warning + "Faulty steering" or "EPAS fault", depending on the type of instrument panel.
MR-372-J84-36B000$396_fra.mif
POWER-ASSISTED STEERING
Fault finding – Interpretation of faults
36B
36B-25V5 MR-372-J84-36B000$462_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
DF054
PRESENT
OR
STOREDTORQUE SENSOR
DEF: Sensor internal electronic fault
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:
Loss or absence of steering assistance with STOP warning light + Message
lighting up.
–The computer records an occurrence context (computer operating values frozen
when fault occurs). To view this information, click on the fault description (camera
symbol).
Within these values, parameter PR143 Internal fault code gives the fault finding
procedure to apply.
If, in the fault occurrence context (computer operating values frozen when fault
occurs) PR108 Computer supply voltage is less than 10 V, check the battery
voltage, the tightness and the condition of the battery terminals and check the
charging circuit.
Procedure to apply for internal fault codes 1 and 69 of PR143.
Contact Techline.
Procedure to apply for internal fault codes 48, 66, 64, 65 and 67 of PR143.
Check the condition of the 3 white EPAS connectors and check that they are locked correctly.
If the fault is still present, contact the Techline.
AFTER REPAIRClear the stored faults.
Check that the EPAS is working.
Deal with any other faults.
DAE_V05_DF054/DAE_V09_DF054/DAE_V0D_DF054
POWER-ASSISTED STEERING
Fault finding – Conformity check
36B
36B-29V5 MR-372-J84-36B000$528_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
Sub-function: assistance
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool.
Application conditions: engine stopped with the ignition on, without moving the
steering wheel, WHEELS STRAIGHT AHEAD (straight line driving).
FunctionParameter or Status Checked
or ActionDisplay and notes Fault finding
Steering wheel
angle (only for
Vdiag 05 and 09)ET020:Steering wheel angle
sensor programmingSTATUS 4In the event of a fault,
apply the interpretation
of status ET020.
PR121:Steering wheel angle- 10 d˚ < X < 10 d˚In the event of a fault,
apply the interpretation
of parameter PR121.
PR007:Steering wheel angle
drift compensation- 10 d˚ < X < 10 d˚In the event of a fault,
apply the interpretation
of parameter PR007.
TorquePR001:Torque applied to the
steering wheel0 Nm (+ 0.2 Nm)In the event of a fault,
apply the interpretation
of parameter PR001.
PR006:Steering motor torque
setpoint0 Nm (+ 0.2 Nm)In the event of a fault,
apply the interpretation
of parameter PR006.
AssistancePR014:Level of assistance
available100% (but assistance
unavailable)In the event of a fault,
apply the interpretation
of parameter PR014.
ComputerET026:Computer calibrationConfig. 1 < X < Config. 5In the event of a fault,
apply the interpretation
of status ET026.
POWER-ASSISTED STEERING
Fault finding – Conformity check
36B
36B-33V5 MR-372-J84-36B000$528_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
Sub-function: assistance
NOTESOnly carry out this conformity check after a complete check with the diagnostic tool.
Test conditions: engine at idling speed.
FunctionParameter or Status Checked
or ActionDisplay and notes Fault finding
Steering wheel
angle (only for
Vdiag 05 and 09)ET020:Steering wheel
angle sensor
programmingSTATUS 4In the event of a fault,
apply the interpretation
of status ET020.
PR121:Steering wheel
angle- 10 d˚ < X < 10 d˚
With action on the steering
wheel:
- 585˚ < X < + 585˚In the event of a fault,
apply the interpretation
of parameter PR121.
PR007:Steering wheel
angle drift
compensation- 10 d˚ < X < 10 d˚In the event of a fault,
apply the interpretation
of parameter PR007.
TorquePR001:Torque applied to
the steering wheelWithout any action on the
steering wheel:
0 Nm (± 0.2 Nm)
With action on the steering
wheel:
- 14 Nm < X <+ 14 NmIn the event of a fault,
apply the interpretation
of parameter PR001.
PR006:Steering motor
torque setpointWithout any action on the
steering wheel:
0 Nm (± 0.2 Nm)
With action on the steering
wheel:
- 5 Nm < X <+ 5 NmIn the event of a fault,
apply the interpretation
of parameter PR006.
AssistancePR014:Level of assistance
available100% (maximum
assistance)In the event of a fault,
apply the interpretation
of parameter PR014.
ComputerET026:Computer
calibrationConfig. 1 < X < Config. 5In the event of a fault,
apply the interpretation
of status ET026.
POWER-ASSISTED STEERING
36B
36B-40V5 MR-372-J84-36B000$726_fra.mif
EPAS
Vdiag no.: 05, 09,
0DPOWER-ASSISTED STEERING
Fault finding – Parameter summary table
Tool parameter Diagnostic tool title
PR001Torque applied to the steering wheel
PR003Vehicle speed
PR006Steering motor torque setpoint
PR007Steering wheel angle offset compensation (only for Vdiag 05 and 09)
PR008Computer temperature
PR009Steering motor temperature
PR012Current absorbed by the motor
PR013Setpoint for current absorbed by the motor
PR014Level of assistance available
PR108Computer feed voltage
PR121Steering wheel angle (only for Vdiag 05 and 09)
MR-372-J84-36B000$726_fra.mif
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
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