Mitsubishi Outlander (2013+). Manual - part 487

TROUBLESHOOTING

ELECTRIC POWER STEERING (EPS)

37-19

STEP 5. M.U.T.-III data list
Check the following data list 

P.37-32

.

• Item No. 22: Power relay voltage

• Item No. 23: Ignition voltage

Q: Is the check result normal?

YES : 

Go to Step 7

NO : 

Go to Step 6

STEP 6. Check whether the diagnosis code is 
reset.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis code C1540 set?

YES : 

Replace the EPS-ECU (Refer to 

P.37-51

).Then go to Step 7.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunctions ).

STEP 7. Check whether the diagnosis code is 
reset.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis code C1540 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.

Code No.C1541 Power supply voltage too low

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnosis code may be set. Prior 
to this diagnosis, diagnose the CAN bus lines 
(Refer to GROUP 54C, CAN Bus Diagnostics 
Table).

• Whenever ECU is replaced, ensure that the 

CAN bus lines are normal.

OPERATION

Power is supplied to the EPS-ECU from the battery 
or the ignition switch.

FUNCTION

To control the steering column shaft assembly, the 
battery voltage is supplied to the EPS-ECU for ener-
gisation.

TROUBLE JUDGEMENT

Check Conditions
The ETACS power supply circuit system diagnosis 
code is not set.

Judgement Criterion

• Power supply voltage is less than 8V.

• The power supply monitor voltage does not meet 

a predetermined voltage stored in the microcom-
puter, and the microcomputer determines that 
there is a problem in the power supply system.

Fail Safe, Back Up Function
The EPS-ECU tapers the motor control and illumi-
nates the electric power steering warning display, 
then sets the diagnosis code No. C1541.

PROBABLE CAUSES

• Malfunction of CAN bus line

• Defective battery

• Charging system failed

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

• Short or open circuit between the EPS-ECU, 

the ETACS-ECU and the fusible link or loose 
connector contact

• Open circuit between the body earth and the 

EPS-ECU or loose connector contact

• Malfunction of the ETACS-ECU

• Malfunction of the EPS-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 3

NO : 

Repair the CAN bus lines (Refer to GROUP 
54C 

− CAN Bus Diagnostics Table ). On 

completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting 
CAN bus lines
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis code C1541 set?

TROUBLESHOOTING

ELECTRIC POWER STEERING (EPS)

37-20

YES : 

Go to Step 3

NO : 

This diagnosis is complete.

STEP 3. Check the battery voltage.
Start the engine and measure the battery voltage 
(Refer to GROUP 54A 

− Battery ).

Q: Is the check result normal?

YES : 

Go to Step 4

NO : 

Check the battery and repair if necessary 
(Refer to GROUP 54A 

− Battery ). Then go 

to Step 10.

STEP 4. Check the charging system.
Start the engine and measure the charging system 
(Refer to GROUP 16 

− On−vehicle Service/Alterna-

tor Output Line Voltage Drop Test )

Q: Is the check result normal?

YES : 

Go to Step 5

NO : 

Check the charging system and repair if 
necessary (Refer to GROUP 16 

− Alternator 

Assembly ).Then go to Step 10.

STEP 5. Voltage measurement at the EPS-ECU 
connector (IG1, +BB, GND terminal)
(1)  Measure the EPS-ECU voltage without 

disconnecting the connector (by backprobing).

(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Measure the voltage between the EPS-ECU 

connector (IG1 terminal) and the EPS-ECU 
connector (GND terminal) or body earth.

OK: Approximately system voltage 

(4) Measure the voltage between the EPS-ECU 

connector (+BB terminal) and the EPS-ECU 
connector (GND terminal) or body earth.

OK: Approximately system voltage 

Q: Is the check result normal?

YES : 

Go to Step 8

NO : 

Go to Step 6

STEP 6. Check of short to power supply, short to 
earth, and open circuit in +BB line between 
fusible link and EPS-ECU connector

Q: Is the check result normal?

YES : 

Go to Step 7

NO : 

Repair the fusible link, connector(s) or 
wiring harness.

STEP 7. Check of short to power supply, short to 
earth, and open circuit in IG1 line between 
EPS-ECU connector and ETACS-ECU connector

Q: Is the check result normal?

YES : 

Go to Step 8

NO : 

Repair the connector(s) or wiring harness.

STEP 8. M.U.T.-III data list
Check the following data list 

P.37-32

.

• Item No. 22: Power relay voltage

• Item No. 23: Ignition voltage

Q: Is the check result normal?

YES : 

Go to Step 10

NO : 

Go to Step 9

STEP 9. Check whether the diagnosis code is 
reset.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis code C1541 set?

YES : 

Replace the EPS-ECU (Refer to 

P.37-51

).Then go to Step 10.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunctions ).

STEP 10. Check whether the diagnosis code is 
reset.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis code C1541 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.

TROUBLESHOOTING

ELECTRIC POWER STEERING (EPS)

37-21

Code No.C1550 ECU internal error

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnosis code may be set. Prior 
to this diagnosis, diagnose the CAN bus lines 
(Refer to GROUP 54C, CAN Bus Diagnostics 
Table).

• Whenever ECU is replaced, ensure that the 

CAN bus lines are normal.

OPERATION

Power is supplied to the EPS-ECU from the battery.

FUNCTION

The motor current is controlled according to the infor-
mation on motor and resolver, and the information on 
CAN bus.

TROUBLE JUDGEMENT

Judgement Criterion
The system data is out of the prestored control 
range, and the microcomputer determines that there 
is an internal problem.

Fail Safe, Back Up Function
The EPS-ECU stops the motor control and illumi-
nates the electric power steering warning display, 
then sets the diagnosis code No. C1550.

PROBABLE CAUSES

• Malfunction of CAN bus line

• Malfunction of the EPS-ECU

Code No.C1561 Engine revolution data (CAN)

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnosis code may be set. Prior 
to this diagnosis, diagnose the CAN bus lines 
(Refer to GROUP 54C, CAN Bus Diagnostics 
Table).

• Whenever ECU is replaced, ensure that the 

CAN bus lines are normal.

OPERATION

EPS-ECU receives engine revolution signal from the 
engine-ECU.

FUNCTION

The engine speed signal is sent to the EPS-ECU for 
motor control.

TROUBLE JUDGEMENT

Check Conditions

• The power supply circuit system diagnosis code 

(No. C1540, C1541) is not set.

• The engine circuit system diagnosis code is not 

set.

Judgement Criterion

• The engine speed signal sent to the EPS-ECU is 

no signal.

• The engine speed signal is not sent from the 

engine-ECU, and the microcomputer determines 
that there is a problem in the engine speed meas-
urement system.

Fail Safe, Back Up Function

• The EPS-ECU illuminates the electric power 

steering warning display, and sets the diagnosis 
code No. C1561. Normally the assist operation is 
continued while the vehicle is driven, but deacti-
vated after the vehicle stopped. 

PROBABLE CAUSES

• Malfunction of CAN bus line

• Malfunction of the EPS-ECU

• Malfunction of the engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the CAN bus lines (Refer to GROUP 
54C 

− CAN Bus Diagnostics Table ). On 

completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting 
CAN bus lines
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis codes C1561 set?

TROUBLESHOOTING

ELECTRIC POWER STEERING (EPS)

37-22

YES : 

Go to Step 3.

NO : 

This diagnosis is complete.

STEP 3. M.U.T.-III data list
Check the following service data 

P.37-32

.

• Item No. 07: Engine speed

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Perform troubleshooting for engine-ECU 
(Refer to GROUP 13A 

− 

Troubleshooting/Inspection Chart for 
Diagnosis code ). Then go to Step 4.

STEP 4. Check whether the diagnosis code is 
reset
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis codes C1561 set?

YES : 

Replace the EPS-ECU (Refer to 

P.37-51

). 

Then go to Step 5.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunction ).

STEP 5. Check whether the diagnosis code is 
reset.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis codes C1561 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.

Code No.C1564 Vehicle speed data invalid

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnosis code may be set. Prior 
to this diagnosis, diagnose the CAN bus lines 
(Refer to GROUP 54C, CAN Bus Diagnostics 
Table).

• Whenever ECU is replaced, ensure that the 

CAN bus lines are normal.

OPERATION

EPS-ECU receives vehicle speed signal from the 
engine-ECU.

FUNCTION

The vehicle speed signal is sent to the EPS-ECU for 
motor control.

TROUBLE JUDGEMENT

Check Conditions

• The power supply circuit system diagnosis code 

(No. C1540, C1541) is not set.

• The engine circuit system diagnosis code is not 

set.

Judgement Criterion
If the microcomputer receives abnormal vehicle 
speed signal from the engine-ECU consecutively 
twice, it determines that the vehicle speed calcula-
tion system is defective.

Fail Safe, Back Up Function
The EPS-ECU illuminates the electric power steering 
warning display, and sets the diagnosis code No. 
C1564 to limit assist operation.

PROBABLE CAUSES

• Malfunction of CAN bus line

• Malfunction of the EPS-ECU

• Malfunction of the engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 3

NO : 

Repair the CAN bus lines (Refer to GROUP 
54C 

− CAN Bus Diagnostics Table ). On 

completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting 
CAN bus lines
(1) Erase the diagnosis code.
(2) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(3) Check if the diagnosis code is set.

Q: Is the diagnosis codes C1564 set?

YES : 

Go to Step 3

NO : 

This diagnosis is complete.