POWER-ASSISTED STEERING
Fault finding – Introduction
36B
36B-5V5 MR-372-J84-36B000$066_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
FAULT FINDING PROCEDURE (continued)
Wiring check
Fault finding problems
Disconnecting the connectors and/or manipulating the wiring harness may temporarily remove the cause of a fault.
Electrical measurements of voltage, resistance and insulation are generally correct, especially if the fault is not
present when the analysis is made (stored fault).
Visual inspection
Look for damage under the bonnet and in the passenger compartment.
Carefully check the fuses, insulators and wiring harness routing.
Look for signs of oxidation.
Physical inspection
While manipulating the wiring harness, use the diagnostic tool to note any change in fault status from stored
to present.
Make sure that the connectors are properly locked.
Apply light pressure to the connectors.
Twist the wiring harness.
If there is a change in status, try to locate the source of the fault.
Inspection of each component
Disconnect the connectors and check the appearance of the clips and tabs, as well as the crimping (no crimping on
the insulating section).
Make sure that the clips and tabs are properly locked in the sockets.
Check that no clips or tabs have been dislodged during connection.
Check the clip contact pressure using an appropriate model of tab.
Resistance check
Check the continuity of entire lines, then section by section.
Look for a short circuit to earth, to + 12 V or to another wire.
If a fault is detected, repair or replace the wiring harness.
POWER-ASSISTED STEERING
Fault finding – Interpretation of faults
36B
36B-16V5 MR-372-J84-36B000$462_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
DF020
PRESENT
OR
STOREDCOMPUTER SUPPLY VOLTAGE
1.DEF: Voltage too low
2.DEF: Voltage too high
CO: Open circuit
NOTESConditions for applying the fault finding procedure to stored faults:
The fault is considered present when the engine is running.
Notes:
This fault causes a degraded assistance (no warning light or message) until assistance
is lost (below 9 V or above 17 V) with STOP warning light + Message.
–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.
Procedure to apply for internal fault code 135 of the PR143
Check the conditioning and positioning of the EPAS supply fuses:
–Power fuse (80A BP81) in the engine fuse box.
–AP44 after ignition fuse (5A) in the Protection and Switching Unit.
Check the condition and tightness of the battery and alternator terminals, as well as the Protection and Switching
Unit bolt.
Carry out fault finding on the charge circuit.
Repair if necessary.
Disconnect the two black connectors from the EPAS computer.
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).
In the event of a fault, check the insulation, continuity and the absence of interference resistance on the
following connections:
8-track connector track 8 + 12 V after ignition
2-track connector track 1 + 12 V before ignition feed
2-track connector track 2 Earth
Repair if necessary.
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_DF020/DAE_V09_DF020/DAE_V0D_DF020
POWER-ASSISTED STEERING
Fault finding – Interpretation of faults
36B
36B-19V5 MR-372-J84-36B000$462_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
DF023
PRESENT
OR
STORED+ AFTER IGNITION FEED
1.DEF: Abnormal voltage
NOTESNotes:
When this fault appears, the assistance gradually cut outs within 5 minutes.
Next time the ignition is switched on, this fault causes the absence of steering
assistance.
Check the power supply fuse for the EPAS:
–AP44 after ignition fuse (5A) in the Protection and Switching Unit.
Check the tightness and the condition of the battery terminals.
Repair if necessary.
Disconnect the 8-track connector of the EPAS computer.
Check the condition and conformity of the connector and its clips.
Check the conformity of the 12 V after ignition feed, with the ignition on and engine running (it must be equal
to the battery voltage).
In the event of a fault, check the insulation, continuity and the absence of interference resistance on the
following connection:
8-track connector track 8 + 12 V after ignition
Repair if necessary.
If the connections are OK but the EPAS computer electrical supply is not correct, run fault finding on the charge
circuit.
AFTER REPAIRClear the stored faults.
Check that the EPAS is working.
Deal with any other faults.
DAE_V05_DF023/DAE_V09_DF023/DAE_V0D_DF023
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
POWER-ASSISTED STEERING
Fault finding – Fault Finding Chart
36B
36B-49V5 MR-372-J84-36B000$924_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
ALP2 Loss of vehicle assistance without warning
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
The vehicle is no longer assisted if the Electric Power Steering fuse is damaged or supply is lost. The steering is
equivalent to manual steering, manoeuvrable when driving even at low speeds, but very difficult to manoeuvre
when stopped.
Since it is no longer being supplied, the EPAS computer is not capable of lighting the warning light, but the
instrument panel lights the STOP warning light + Message 4 seconds after the loss of the feed causing the loss
of assistance.
The driver will only become aware of the fault through noticing the loss of assistance at the steering wheel.
Check the fuses for the electric power-assisted steering:
Power fuse 80A BP81 in the engine fuse box.
5A AP44 + after ignition fuse on the UPC.
Check the condition of the electric power-assisted steering connectors and repair if necessary.
Check that the electrical feeds to the computer are correct:
2-track connector track 2vehicle earth
2-track connector track 1+ battery feed
8-track connector track 8+ after ignition feed
Repair if necessary.
Check the insulation, continuity and the absence of interference resistance on the connections between the electric
power-assisted steering computer and the instrument panel.
8-track connector track 6 track 30 of the instrument panel
8-track connector track 4 track 29 of the instrument panel
Check that the steering column and steering rack are in sound mechanical condition.
Repair if necessary.
Make sure that the front axle components, such as the track rod ends and shock absorber base plates, are in sound
mechanical condition.
Repair if necessary.
If the fault is still present, contact the Techline.
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_ALP2/DAE_V09_ALP2/DAE_V0D_ALP2
POWER-ASSISTED STEERING
Fault finding – Fault Finding Chart
36B
36B-50V5 MR-372-J84-36B000$924_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
ALP3 Poor vehicle handling
NOTESOnly consult this customer complaint after a complete check with the diagnostic tool.
Check the pressure and condition of the tyres, the condition of the joints and the front axle geometry.
Check the vehicle battery voltage and the condition of the battery terminals.
Repair if necessary.
Check the status and presence of the Electric Power Steering system power supply fuse.
Repair if necessary.
Check the insulation, continuity and absence of interference resistance on the wiring harness between the
battery and the 2-track EPAS connector.
Repair if necessary.
Check that status ET026 Computer calibration corresponds to the vehicle equipment.
Configure the computer correctly using the diagnostic tool, if necessary (see Configuration and Programming).
If the fault is still present, contact the Techline.
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_ALP3/DAE_V09_ALP3/DAE_V0D_ALP3
POWER-ASSISTED STEERING
Fault finding – Fault Finding Chart
36B
36B-54V5 MR-372-J84-36B000$924_fra.mif
EPAS
Vdiag no.: 05, 09,
0D
ALP7 Assistance available for 5 minutes after switching off the ignition
NOTESNote :
This fault may arise if the vehicle speed multiplex signal is faulty or if the ignition is
switched off before the vehicle has come to a complete halt.
Check the vehicle battery voltage.
Check the charge circuit if necessary.
Check that parameter PR003 Vehicle speed is correct (see Conformity check).
Run a multiplex network test (see 88B, Multiplex).
Repair if necessary.
Carry out fault finding on the injection system (see 13B, Diesel injection and 17B, Petrol injection).
Repair if necessary.
Check the fuses for the electric power-assisted steering:
5A AP44 + after ignition fuse on the Protection and Switching Unit.
Repair if necessary.
Check the conformity of the + 12 after ignition feed for the computer:
Electric Power Assisted Steering Computer Connector:
8-track connector track 8+ After ignition
Repair if necessary.
If the fault is still present, contact the Techline.
AFTER REPAIRPerform a test using the diagnostic tool.
DAE_V05_ALP7/DAE_V09_ALP7/DAE_V0D_ALP7