Mitsubishi Colt Ralliart. Manual - part 452

TROUBLESHOOTING

POWER STEERING

37-75

DIAGNOSIS PROCEDURE

STEP 1. Check the connectors and terminals.

•

AC314189AE

Connector: B-37, B-38

B-37 

B-38 

Harness side

B-37

21
22

B-38

Electric power steering-ECU connectors B-37 and 

B-38

Check the connectors above for improper engage-
ment, terminal damage or terminal drawn in the con-
nector case.

Q: Are the connectors and terminals in good 

condition?
YES : 

Go to Step 2.

NO : 

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

STEP 2. Voltage measurement at electric power 
steering-ECU connector B-37.

•

AC314189AF

Connector: B-37

Harness side

Disconnect the connector, and measure at the wiring 

harness side.

• Ignition Switch: ON

•

AC313972 BW

Harness side

 B-37

Measure the voltage between electric power steer-

ing-ECU connector B-37 terminal No.5 and body 
earth

OK: system voltage

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Go to Step 5.

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-76

STEP 3. Voltage measurement at electric power 
steering-ECU connector B-38.

•

AC314189

AC314189

AC314189AG

Connector: B-38

Harness side

Disconnect the connector, and measure at the wiring 

harness side.

•

AC313972 BX

Harness side
connector B-38
(Rear view)

Measure the voltage between electric power steer-

ing-ECU connector B-38 terminal No.22 and 
body earth

OK: system voltage

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Go to Step 6.

STEP 4. Resistance measurement at electric 
power steering-ECU connector B-38.

•

AC314189

AC314189

AC314189AG

Connector: B-38

Harness side

Disconnect the connector, and measure at the wiring 

harness side.

•

AC313972 BY

Harness side
connector B-38
(Rear view)

Measure the resistance between electric power 

steering-ECU connector B-38 terminal No.21 and 
body earth

OK: Continuity exists (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 8.

NO : 

Go to Step 7.

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-77

STEP 5. Check the wiring harness wires.
NOTE: 

AC313870AI

Connector: B-110

Junction Block (Front view)

Junction block side

12

5

9

8

1 2

1011

3 4

14

13

6 7

AC313872AJ

Connector: B-129

Junction Block (Rear view)

Junction block side

Prior to the wiring harness inspection, check junction 
block connectors B-110 and B-129, and repair if nec-
essary.

•

AC314189AF

Connector: B-37

Harness side

The harness wire between electric power steer-

ing-ECU connector B-37 and ignition switch (IG1) 
B-141

Check the harness wire above for damage or other 
problem.

Q: Is the wiring harness in good condition?

YES : 

Go to Step 8.

NO : 

Repair the wiring harness.

STEP 6. Check the wiring harness wires.

•

AC314189

AC314189

AC314189AG

Connector: B-38

Harness side

Harness wire between electric power steering-ECU 

connector B-38 and fusible link No.22

Check the harness wire above for damage or other 
problem.

Q: Is the wiring harness in good condition?

YES : 

Go to Step 8.

NO : 

Repair the wiring harness.

STEP 7. Check the wiring harness wires.

•

AC314189

AC314189

AC314189AG

Connector: B-38

Harness side

Harness wire between electric power steering-ECU 

connector B-38 and body earth

Check the harness wire above for damage or other 
problem.

Q: Is the wiring harness in good condition?

YES : 

Go to Step 8.

NO : 

Repair the wiring harness.

STEP 8. Retest the system.

Q: Is the check result normal?

YES : 

The malfunction is intermittent. Refer to 

GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunction 

P.00-13

.

NO : 

Replace the electric power steering-ECU 
(Refer to 

P.37-102

). 

Main

Index

Group

TOC

TROUBLESHOOTING

POWER STEERING

37-78

Inspection Procedure 3: Although the electric power steering system warning lamp illuminates but 
diagnosis code is not stored.

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

Main

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