Mitsubishi Colt Ralliart. Manual — part 446

TROUBLESHOOTING

POWER STEERING

37-51

STEP 2. Check the voltage in the power supply
line.

AC314189

AC314189

AC314189AG

Connector: B-38

Harness side

Disconnect connector B-38 and measure the volt-
age.

•

AC313972 BX

Harness side
connector B-38
(Rear view)

Measure the voltage between B-38 terminal 22 and

body earth.

OK: System voltage

Q: Is the measurement value normal?

YES :

Go to Step 3.

NO :

Check the wiring harness wires and
connectors between fusible link No.4 and
electric power steering-ECU connector B-38
and repair if necessary.

STEP 3. Check the resistance in the earth line.

AC314189

AC314189

AC314189AG

Connector: B-38

Harness side

Disconnect connector B-38 and measure the resist-
ance.

•

AC313972 BY

Harness side
connector B-38
(Rear view)

Measure the resistance between B-38 terminal 21

and body earth.

OK: Continuity exists (2

Ω or less)

Q: Is the measurement value normal?

YES :

Go to Step 4.

NO :

Check the wiring harness wires and
connectors between body earth and electric
power steering-ECU connector B-38 and
repair if necessary.

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-52

STEP 4. Check whether the diagnosis code is
reset.

AC206895

AC

Diagnosis

connector

MB991827

MB991824

MB991910

CAUTION

Before connecting or disconnecting the
M.U.T.-III, turn the ignition switch to the "LOCK"
(OFF) position.
Check again if the diagnosis code is set.
(1) Turn the ignition switch to the "ON" position.

(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF)

position.

(4) Turn the ignition switch to the "ON" position.
(5) Start the engine, and check the diagnosis code.
(6) Turn the ignition switch to the "LOCK" (OFF)

position.

(7) Disconnect M.U.T.-III.

Q: Is diagnosis code C1861 set?

YES :

Replace the electric power steering-ECU

(Refer to

P.37-102

).

NO :

The malfunction is intermittent. Refer to
GROUP 00, How to Use
Troubleshooting/Inspection Service Points

−

How to Cope with Intermittent Malfunction

P.00-13

.

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-53

Code No.U1073 Bus off

CAUTION

• If the electric power steering-ECU sets diagnosis code No.U1073, diagnose the CAN bus lines. If

there is any fault in the CAN bus lines, an incorrect diagnosis code may be set.

•

ENGINE-CVT-ECU

DIAGNOSIS
CONNECTOR

FRONT SIDE

COMBINATION
METER

ABS-ECU

EPS-ECU

Wire colour code
B : Black
LG : Light green
G : Green
L: Blue
W : White
Y: Yellow
SB : Sky blue
BR : Brown
O : Orange
GR : Grey
R : Red
P : Pink
V : Violet
PU: Purple

CAN Communication Circuit

Whenever the ECU is replaced, ensure that the communication circuit is normal.

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-54

TROUBLE JUDGMENT

When the electric power steering-ECU is bus off, it is
memorised.

COMMENTS ON TROUBLE SYMPTOM

Harness wire(s), connector(s) or the electric power
steering-ECU may be defective.

PROBABLE CAUSES

• Defective wire(s) or connector(s) in the CAN bus

lines

• Malfunction of the electric power steering-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics

AC206895

AC

Diagnosis

connector

MB991827

MB991824

MB991910

CAUTION

Before connecting or disconnecting the
M.U.T.-III, turn the ignition switch to the "LOCK"
(OFF) position.
(1) Connect M.U.T.-III to the 16-pin diagnosis

connector.

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF)

position.

Q: Is the check result normal?

YES : .

Go to Step 2.

NO : .

Repair the CAN bus line (Refer to GROUP

54D, Diagnosis

P.54D-13

).

STEP 2. Check whether the diagnosis code is
reset.

AC206895

AC

Diagnosis

connector

MB991827

MB991824

MB991910

CAUTION

Before connecting or disconnecting the
M.U.T.-III, turn the ignition switch to the "LOCK"
(OFF) position.
Check again if the diagnosis code is set.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF)

position.

(4) Turn the ignition switch to the "ON" position.
(5) Start the engine.
(6) Recheck whether diagnosis code U1073 is set.
(7) Turn the ignition switch to the "LOCK" (OFF)

position.

(8) Disconnect M.U.T.-III.

Q: Is diagnosis code U1073 set?

YES :

Replace the electric power steering-ECU

(Refer to

P.37-102

).

NO :

The malfunction is intermittent. Refer to
GROUP 00, How to Use
Troubleshooting/Inspection Service Points

−

How to Cope with Intermittent Malfunction

P.00-13

.

Main

Index

Group

TOC