Mitsubishi Colt Ralliart. Manual - part 443

TROUBLESHOOTING

POWER STEERING

37-39

Code No.C1532 Over real current of motor

CAUTION

• If the electric power steering-ECU sets diagnosis code No.C1532, 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 current does not meet a predeter-

mined limit stored in the microcomputer, and the 
microcomputer determines that there is a prob-
lem in the motor current limit.
Criteria for judging malfunction

• Actual measurement value of the motor cur-

rent (absolute value) is more than 65 A 

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

37-40

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III 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, and check the diagnosis code.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is diagnosis code C1531 set?

YES : 

Carry out the troubleshooting for diagnosis 

code C1531 (Refer to 

P.37-36

).

NO : 

Go to Step 2.

STEP 2. 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 3.

NO : 

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

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.

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-41

(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 if the diagnosis code is set.
(7) Turn the ignition switch to the "LOCK" (OFF) 

position.

(8) Disconnect M.U.T.-III.

Q: Is diagnosis code C1532 set?

YES : 

Replace the electric power steering-ECU 

(Refer to 

P.37-102

). If the concern is not 

eliminated after the electric power 
steering-ECU is replaced, replace the power 
steering gear box.

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

.

Code No.C1534 Under real current of motor

CAUTION

• If the electric power steering-ECU sets diagnosis code No.C1534, 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 current is less than the lower limit of 

the assist permission current stored in the micro-
computer, but assist torque is produced. Then the 
microcomputer determines that there is a prob-
lem in the motor current.

Criteria for judging malfunction

• Actual measurement value of the motor cur-

rent (absolute value) is 1 A or less and assist 
torque (absolute value) is more than 0.3 N

⋅m

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-42

PROBABLE CAUSES

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

• Malfunction of the electric power steering-ECU

• Motor malfunction

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 
open circuit.

AC314189AC

Connector: B-38-1

Harness side

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

•

AC400133AB

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

Measure the resistance between electric power 

steering-ECU connector B-38-1 terminals 31 and 
32.

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the harness wire and connector, or 
replace the steering gear and linkage 
assembly (Refer to 

P.37-96

).

Main

Index

Group

TOC