Mitsubishi Colt Ralliart. Manual - part 448

TROUBLESHOOTING

POWER STEERING

37-59

Code No.U1102 CAN communication time-out with ABS-ECU

CAUTION

• If more than three minutes elapse after the ignition switch is turned ON without starting engine, 

the electric power steering-ECU may set diagnosis codes U1100 and U1102 as the M.U.T.-III shows 
a diagnosis code status as stored.

• If the electric power steering-ECU sets diagnosis code No.U1102, 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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POWER STEERING

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TROUBLE JUDGMENT

The electric power steering-ECU receives vehicle 
speed data (wheel speed sensor data) from the 
ABS-ECU through the CAN bus lines. If the electric 
power steering-ECU cannot receive the vehicle 
speed data (wheel speed sensor data) from the 
ABS-ECU for 60 seconds, diagnosis code U1102 will 
be set.

COMMENTS ON TROUBLE SYMPTOM

The M.U.T.-III shows a diagnosis code status as 

active

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

CAN bus lines between the ABS-ECU and the 
electric power steering-ECU, or the power supply 
to these ECUs, or the ECUs themselves are 
defective.

The M.U.T.-III shows a diagnosis code status as 

stored

• Carry out diagnosis by referring to GROUP 00, 

How to Use Troubleshooting/Inspection Service 
Points 

− How to treat past trouble 

P.00-13

. Carry 

out diagnosis with particular emphasis on con-
nector(s) or wiring harness in the CAN bus lines 
between the ABS-ECU and the electric power 
steering-ECU, and the power supply to the 
ABS-ECU.

NOTE: For a The M.U.T.-III shows a diagnosis code 

status as stored, you can not find it by the 
M.U.T.-III CAN bus diagnostics even if there is 
any failure in CAN bus lines. In this case, refer to 
GROUP 00, How to Use Troubleshooting/Inspec-
tion Service Points-How to Cope with Intermittent 
Malfunction 

P.00-13

 and check the CAN bus 

lines. You can narrow down the possible cause of 
the trouble by referring to the diagnosis code, 
which is set regarding the CAN communica-
tion-linked ECUs (Refer to GROUP 54D, CAN 
Bus Line Diagnostic Flow 

P.54D-7

).

PROBABLE CAUSES

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

• Malfunction of the ABS-ECU

• 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

). Then go to Step 

2.

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POWER STEERING

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

position.

Q: Is the diagnosis code set?

YES : 

Diagnose the ABS system (Refer to 

GROUP 35B, Troubleshooting 

P.35B-7

 ).

NO : 

Go to Step 3.

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 and wait for at least 60 seconds.
(6) Recheck whether diagnosis code U1102 is set.
(7) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is diagnosis code U1102 set?

YES : 

Replace the electric power steering-ECU 

(Refer to 

P.37-102

). Then go to Step 4.

NO : 

Go to Step 4.

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POWER STEERING

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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 U1102 set?

YES : 

Replace the hydraulic unit (Refer to 

GROUP 35B, Hydraulic Unit 

P.35B-78

).

NO : 

This diagnosis is complete.

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