Mitsubishi Colt Ralliart. Manual - part 441

TROUBLESHOOTING

POWER STEERING

37-31

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

). Then go to Step 

2.

STEP 2. M.U.T.-III other system diagnosis code

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) Check that a ABS system diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is an ABS system diagnosis code set?

YES : 

Diagnose the ABS system (Refer to 

GROUP 35B, Troubleshooting 

P.35B-7

).

NO : 

Go to Step 3.

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TROUBLESHOOTING

POWER STEERING

37-32

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) Recheck whether diagnosis code C1521 is set.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is diagnosis code C1521 set?

YES : 

Replace the electric power steering-ECU 

(Refer to 

P.37-102

). Then go to Step 4.

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

.

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) Recheck whether diagnosis code C1521 is set.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

(7) Disconnect M.U.T.-III.

Q: Is diagnosis code C1521 set?

YES : 

Replace the hydraulic unit (Integrated with 

ABS-ECU) (Refer to GROUP 35B,  
Hydraulic Unit 

P.35B-78

 ).

NO : 

This diagnosis is complete.

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TROUBLESHOOTING

POWER STEERING

37-33

Code No.C1522 Engine speed input malfunction

CAUTION

• If the electric power steering-ECU sets diagnosis code No.C1522, 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.

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TROUBLESHOOTING

POWER STEERING

37-34

DIAGNOSIS CODE SET CONDITIONS

• If the system receives an abnormal engine speed 

signal and the microprocessor determines that 
the engine speed measurement system is defec-
tive. 
Criteria for judging malfunction

• When the vehicle maintains the vehicle speed 

of 15 km/h or above and the engine speed 
signal stays 0 rpm for 60 seconds

PROBABLE CAUSES

• Defective wire(s) or connector(s) in the crank-

shaft angle sensor input circuit of the 
engine-CVT-ECU

• Malfunction of the engine-CVT-ECU

• Malfunction of the electric power steering-ECU

• The vehicle kept running with the engine stopped 

for 60 seconds or more.

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

). Then go to Step 

2.

STEP 2. M.U.T.-III other system diagnosis code

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) Check that an engine control system diagnosis 

code is set.

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

position.

Q: Is an engine control system diagnosis code set?

YES : 

Diagnose the engine control system (Refer 

to GROUP 13A, Troubleshooting 

P.13A-20

 

<4A9>, GROUP 13B, Troubleshooting 

P.13B-18

 <4G1>). Then go to Step 3.

NO : 

Go to Step 3.

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