Mitsubishi Lancer (4A9 engine). Manual — part 142

REVERSING SENSOR SYSTEM

CHASSIS ELECTRICAL

54A-230

YES :

Replace the corner sensor/back sensor-

ECU.

NO :

Replace the rear corner sensor (RH).

STEP 5. Diagnosis code recheck
Temporarily replace the rear corner sensor (LH), and
then check if the diagnosis code No. B2531 is set.

Q: Is the diagnosis code set?

YES :

Replace the corner sensor/back sensor-

ECU.

NO :

Replace the rear corner sensor (LH).

STEP 6. Diagnosis code recheck
Temporarily replace the back sensor (RH), and then
check if the diagnosis code No. B2533 is set.

Q: Is the diagnosis code set?

YES :

Replace the corner sensor/back sensor-

ECU.

NO :

Replace the back sensor (RH).

STEP 7. Diagnosis code recheck
Temporarily replace the back sensor (LH), and then
check if the diagnosis code No. B2535 is set.

Q: Is the diagnosis code set?

YES :

Replace the corner sensor/back sensor-

ECU.

NO :

Replace the back sensor (LH).

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
This diagnosis code is set when corner sensor/back
sensor-ECU has ceased the CAN communication
(bus off).

JUDGEMENT CRITERIA
The corner sensor/back sensor-ECU judges the bus-
off error.

PROBABLE CAUSES

• Malfunction of the corner sensor/back sensor-

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 corner
sensor/back sensor-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 corner sensor/back sensor-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 ).

REVERSING SENSOR SYSTEM

CHASSIS ELECTRICAL

54A-231

Code No. U0100 Engine-ECU CAN timeout

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 corner sensor/back sensor-ECU sets diagnosis
code No.U0100 when it cannot receive signals from
the engine ECU.

JUDGEMENT CRITERIA
The corner sensor/back sensor-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 corner sensor/back sensor-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

− Diagnosis Code Chart <1600>,

GROUP 13B

− Diagnosis Code Chart

<1800-PETROL-DOHC, 2000>, GROUP
13C

− Diagnosis Code Chart <DIESEL> or

GROUP 13F

− Diagnosis Code Chart

<1800-SOHC>).

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 corner
sensor/back sensor-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 corner sensor/back sensor-
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 corner sensor/back sensor-

ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the corner sensor/back sensor-
ECU and the engine-ECU. (Refer to
GROUP 00

− How to Use Troubleshooting/

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

REVERSING SENSOR SYSTEM

CHASSIS ELECTRICAL

54A-232

Code No.U0121 ASC/ABS-ECU CAN timeout

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 corner sensor/back sensor-ECU sets diagnosis
code No.U0121 when it cannot receive signals from
the ABS-ECU or ASC-ECU.

JUDGEMENT CRITERIA
The corner sensor/back sensor-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 corner sensor/back sensor-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 corner
sensor/back sensor-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 corner sensor/back sensor-
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 corner
sensor/back sensor-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 corner sensor/back sensor-

ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the corner sensor/back sensor-
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 .)

REVERSING SENSOR SYSTEM

CHASSIS ELECTRICAL

54A-233

Code No. U0141 ETACS-ECU CAN timeout

CAUTION

• If the diagnosis code No. U0141 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 corner sensor/back sensor-ECU sets diagnosis
code No.U0141 when it cannot receive signals from
the ETACS-ECU.

JUDGEMENT CRITERIA
The corner sensor/back sensor-ECU cannot receive
the signal from the ETACS-ECU via the CAN bus
line.

PROBABLE CAUSES

• Malfunction of CAN bus line

• Malfunction of ETACS-ECU

• Malfunction of corner sensor/back sensor-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 again if the diagnosis code is set to the
ETACS-ECU.

Q: Is the diagnosis code set?

YES :

Troubleshoot the ETACS-ECU. (Refer to

GROUP 54A

− ETACS-ECU −

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. U0141 is set to
engine-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 corner
sensor/back sensor-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 ETACS-ECU.

NO :

A poor connection, open circuit, or other
intermittent malfunction in the CAN bus line
between the corner sensor/back sensor-
ECU and the ETACS-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 corner
sensor/back sensor-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 corner sensor/back sensor-
ECU and the ETACS-ECU. (Refer to
GROUP 00

− How to Use Troubleshooting/

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