Mitsubishi Lancer (4A9 engine). Manual — part 110

HEADLAMP

CHASSIS ELECTRICAL

54A-102

Code No. B2512 ECU internal error (EEPROM)

CAUTION

Before replacing the ECU, ensure that the power
supply circuit, the earth circuit and the communi-
cation circuit are normal.
DIAGNOSTIC FUNCTION
If a trouble occurs in headlamp automatic levelling-
ECU, AFS or headlamp automatic levelling system
warnings are displayed on the multi information dis-
play and code No. B2512 is stored.

JUDGEMENT CRITERIA
The headlamp automatic levelling-ECU detects the
data error at EEPROM reading or writing.

PROBABLE CAUSE
Malfunction of the headlamp automatic levelling-
ECU

DIAGNOSIS PROCEDURE

Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to headlamp
automatic levelling-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from "LOCK" (OFF)

position to "ON" position.

(3) Check if diagnosis code is set.

Q: Is the diagnosis code set?

YES :

Replace the headlamp automatic levelling-

ECU.

NO :

The trouble can be an intermittent
malfunction (Refer to GROUP 00

− How to

use Troubleshooting/inspection Service
Points

− How to Cope with Intermittent

Malfunction ).

Code No.U0001 Bus off (CAN-C)

CAUTION

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

an incorrect diagnosis code may be set. Prior
to this diagnosis, always diagnose the CAN
bus lines.

• Before replacing the ECU, ensure that the

power supply circuit, the earth circuit and the
communication circuit are normal.

DIAGNOSTIC FUNCTION
When headlamp automatic levelling-ECU is returned
from the bus-off state or when the bus-off error is
indicated to the headlamp automatic levelling-ECU
state, AFS warnings are displayed on the multi infor-
mation display and code No. U0001 (CAN-C) is
stored.

JUDGEMENT CRITERIA
The headlamp automatic levelling-ECU judges the
bus-off error.

PROBABLE CAUSES

• Malfunction of the headlamp automatic levelling-

ECU

• Malfunction of wiring harness or connector

DIAGNOSIS PROCEDURE

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

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN bus line (Refer to GROUP
54C

− Troubleshooting ).

STEP 2. Check whether the diagnosis code is
reset.
Check again if the diagnosis code is set to the head-
lamp automatic levelling-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from "LOCK" (OFF)

position to "ON" position.

(3) Check if diagnosis code is set.

Q: Is the diagnosis code set?

YES :

Replace the headlamp automatic levelling-

ECU.

NO :

The trouble can be an intermittent
malfunction (Refer to GROUP 00

− How to

use Troubleshooting/inspection Service
Points

− How to Cope with Intermittent

Malfunction ).

HEADLAMP

CHASSIS ELECTRICAL

54A-103

Code No. U0100 Engine CAN time-out

CAUTION

• If the diagnosis code No. U0100 is set, be sure

to diagnose the CAN bus line.

• Before replacing the ECU, ensure that the

power supply circuit, the earth circuit and the
communication circuit are normal.

DIAGNOSTIC FUNCTION
The headlamp automatic levelling-ECU sets diagno-
sis code No.U0100 when it cannot receive signals
from the engine ECU.

JUDGEMENT CRITERIA
The headlamp automatic levelling-ECU cannot
receive the signal from the engine-ECU via the CAN
bus line.

PROBABLE CAUSES

• Malfunction of CAN bus line

• Malfunction of engine-ECU

• Malfunction of headlamp automatic levelling-ECU

DIAGNOSIS PROCEDURE

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

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN bus line (Refer to GROUP
54C

− Troubleshooting ).

STEP 2. M.U.T.-III other system diagnosis code
Check if diagnosis code is set to the engine-ECU.

Q: Is the diagnosis code set?

YES :

Troubleshoot the engine (Refer to GROUP

13A

− Troubleshooting).

NO :

Go to Step 3.

STEP 3. Check the M.U.T.-III Diagnosis code for
other systems
Check if the diagnosis code No. U0100 is set to
ETACS-ECU.

Q: Is the diagnosis code set?

YES :

Go to Step 4.

NO :

Go to Step 5.

STEP 4. Diagnosis code recheck
Check again if the diagnosis code is set to the head-
lamp automatic levelling-ECU.
(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 set?

YES :

Replace the engine-ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the headlamp automatic levelling-
ECU and the engine-ECU. (Refer to
GROUP 00

− How to Use Troubleshooting/

Inspection Service Points - How to Cope
with Intermittent Malfunction .)

STEP 5. Diagnosis code recheck
Check again if the diagnosis code is set to the head-
lamp automatic levelling-ECU.
(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 set?

YES :

Replace the headlamp automatic levelling-

ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the headlamp automatic levelling-
ECU and the engine-ECU. (Refer to
GROUP 00

− How to Use Troubleshooting/

Inspection Service Points - How to Cope
with Intermittent Malfunction .)

HEADLAMP

CHASSIS ELECTRICAL

54A-104

Code No.U0121 ASC/ABS CAN time-out

CAUTION

• If the diagnosis code No. U0121 is set, be sure

to diagnose the CAN bus line.

• Before replacing the ECU, ensure that the

power supply circuit, the earth circuit and the
communication circuit are normal.

DIAGNOSTIC FUNCTION
The headlamp automatic levelling-ECU sets diagno-
sis code No.U0121 when it cannot receive signals
from the ABS-ECU or ASC-ECU. In addition, the
AFS or headlamp automatic levelling system warning
is displayed on the multi information display.

JUDGEMENT CRITERIA
The headlamp automatic levelling-ECU cannot
receive the signal from the ABS-ECU or ASC-ECU
via the CAN bus line.

PROBABLE CAUSES

• Malfunction of CAN bus line

• Malfunction of ABS-ECU or ASC-ECU

• Malfunction of headlamp automatic levelling-ECU

DIAGNOSIS PROCEDURE

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

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN bus line (Refer to GROUP
54C

− Troubleshooting ).

STEP 2. M.U.T.-III other system diagnosis code
Check if diagnosis code is set to the ABS-ECU or
ASC-ECU.

Q: Is the diagnosis code set to the any of the above?

Set to the ABS-ECU. :

Troubleshoot the ABS.

Refer to GROUP 35B

− Troubleshooting .

Set to the ASC-ECU. :

Troubleshoot the ASC.

Refer to GROUP 35C

− Troubleshooting .

NO :

Go to Step 3.

STEP 3. Check the M.U.T.-III Diagnosis code for
other systems
Check if the diagnosis code No. U0121 is set to
ETACS-ECU.

Q: Is the diagnosis code set?

YES :

Go to Step 4.

NO :

Go to Step 5.

STEP 4. Diagnosis code recheck
Check again if the diagnosis code is set to the head-
lamp automatic levelling-ECU.
(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 set?

YES :

Replace the ABS-ECU or ASC-ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the headlamp automatic levelling-
ECU and the ABS-ECU or ASC-ECU.
(Refer to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points -
How to Cope with Intermittent Malfunction .)

STEP 5. Diagnosis code recheck
Check again if the diagnosis code is set to the head-
lamp automatic levelling-ECU.
(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 set?

YES :

Replace the headlamp automatic levelling-

ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the headlamp automatic levelling-
ECU and the ABS-ECU or ASC-ECU.
(Refer to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points -
How to Cope with Intermittent Malfunction .)

HEADLAMP

CHASSIS ELECTRICAL

54A-105

Code No. U0126 Steering wheel sensor CAN time-out

CAUTION

• If the diagnosis code No. U0126 is set, be sure

to diagnose the CAN bus line.

• Before replacing the ECU, ensure that the

power supply circuit, the earth circuit and the
communication circuit are normal.

DIAGNOSTIC FUNCTION
The headlamp automatic levelling-ECU sets diagno-
sis code No. U0126 when it cannot receive signals
from the steering wheel sensor. In addition, the AFS
warning is displayed on the multi information display.

JUDGEMENT CRITERIA
The headlamp automatic levelling-ECU cannot
receive the signal from the steering wheel sensor via
the CAN bus line.

PROBABLE CAUSES

• Malfunction of CAN bus line

• Malfunction of steering wheel sensor

• Malfunction of headlamp automatic levelling-ECU

DIAGNOSIS PROCEDURE

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

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the CAN bus line (Refer to GROUP
54C

− Troubleshooting ).

STEP 2. M.U.T.-III other system diagnosis code
Check if diagnosis code is set to the steering wheel
sensor.

Q: Is the diagnosis code set?

YES :

Troubleshoot the steering wheel sensor.

Refer to GROUP 35C

− Troubleshooting .

NO :

Go to Step 3.

STEP 3. Check the M.U.T.-III Diagnosis code for
other systems
Check if the diagnosis code No. U0126 is set to
ETACS-ECU.

Q: Is the diagnosis code set?

YES :

Go to Step 4.

NO :

Go to Step 5.

STEP 4. Diagnosis code recheck
Check again if the diagnosis code is set to the head-
lamp automatic levelling-ECU.
(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 set?

YES :

Replace the steering wheel sensor.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the headlamp automatic levelling-
ECU and the steering wheel sensor. (Refer
to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points -
How to Cope with Intermittent Malfunction .)

STEP 5. Diagnosis code recheck
Check again if the diagnosis code is set to the head-
lamp automatic levelling-ECU.
(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 set?

YES :

Replace the headlamp automatic levelling-

ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the headlamp automatic levelling-
ECU and the steering wheel sensor. (Refer
to GROUP 00

− How to Use

Troubleshooting/Inspection Service Points -
How to Cope with Intermittent Malfunction .)