Mitsubishi Colt Ralliart. Manual - part 442

TROUBLESHOOTING

POWER STEERING

37-35

STEP 3. M.U.T.-III data list

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) Set M.U.T.-III to data reading mode, and check 

the data list item.

• Item 12: Engine speed

• Item 87: Tachometer (Refer to GROUP 54A, 

Combination meter 

− Data list reference table 

P.54A-59

)

OK: The tachometer normal and the read-
ing on the tachometer nearly match the 
indication on M.U.T.-III.

(7) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is the engine speed input normal?

YES : 

Go to Step 4.

NO : 

Replace the engine-CVT-ECU (Refer to 
GROUP 13A, Engine-CVT-ECU 

P.13A-372

).

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.
(6) Recheck whether diagnosis code C1522 is set.
(7) Turn the ignition switch to the "LOCK" (OFF) 

position.

(8) Disconnect M.U.T.-III.

Q: Is diagnosis code C1522 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

37-36

Code No.C1531 Motor terminal voltage abnormality

CAUTION

• If the electric power steering-ECU sets diagnosis code No.C1531, diagnose the CAN bus lines. If 

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

•

ELECTRIC POWER STEERING-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 : Gray     R : Red     P : Pink     V : Violet

Motor Circuit

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

DIAGNOSIS CODE SET CONDITIONS

• The motor terminal voltage does not meet a pre-

determined voltage stored in the microcomputer, 
and the microcomputer determines that there is a 
problem in the motor terminal voltage.
Criteria for judging malfunction

• Right and left terminal voltages of the motor 

are less than 0.5 V. 

• Both right and left terminal voltages of the 

motor are more than the power supply voltage 
− 1.13 V.

PROBABLE CAUSES

• Defective harness wire(s) or connector(s)

• Defective motor of the steering gear and linkage 

assembly

• Malfunction of the electric power steering-ECU

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-37

DIAGNOSTIC PROCEDURE

STEP 1. Check the electric power steering-ECU 
connector B-38-1.

•

AC314189AC

Connector: B-38-1

Harness side

B-38-1 electric power steering-ECU connector
Check the connectors above for improper engage-
ment, terminal damage or terminal drawn in the con-
nector case.

Q:  Is the check result normal?

YES : 

Go to Step 2.

NO : 

 Repair the connector(s) or terminal(s).

STEP 2. Check the motor wires of the steering 
gear and linkage assembly wiring harness for 
short to earth.

AC314189AC

Connector: B-38-1

Harness side

Disconnect electric power steering-ECU connector 
B-38-1 and measure the resistance.

•

AC313972BV

Harness side
connector B-38-1
(Rear view)

Measure the resistance between electric power 

steering-ECU connector B-38-1 terminal 31 and 
body earth.

• Measure the resistance between electric power 

steering-ECU connector B-38-1 terminal 32 and 
body earth.

OK: Open circuit or more than 300 

Ω

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Replace the steering gear and linkage 
assembly (Refer to 

P.37-96

).

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-38

STEP 3. 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 C1531 is set.
(7) Turn the ignition switch to the "LOCK" (OFF) 

position.

(8) Disconnect M.U.T.-III.

Q: Is diagnosis code C1531 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