Mitsubishi Lancer (4A9 engine). Manual - part 215

ETACS

CHASSIS ELECTRICAL

54A-522

PROBABLE CAUSES

• Malfunction of CVT-ECU

• Malfunction of A/T-ECU

• Malfunction of the ETACS-ECU

• Malfunction of the CAN bus

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 CVT-ECU, A/T-
ECU.

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

Set to the CVT-ECU. : 

Troubleshoot the CVT. Refer 

to GROUP 23A 

− Diagnosis code chart .

Set to the A/T-ECU. : 

Troubleshoot the A/T. Refer 

to GROUP 23C 

− Diagnosis code chart .

The diagnosis code is not set. : 

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code
Check if the diagnosis code No. U0101 is set to the 
engine-ECU.

Q: Is the diagnosis code set?

YES : 

Go to Step 4.

NO : 

Go to Step 5.

STEP 4. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 CVT-ECU, A/T-ECU.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the CVT-ECU, A/T-ECU and the ETACS-
ECU (GROUP 00 

− How to use 

Troubleshooting/inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 ETACS-ECU.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the CVT-ECU, A/T-ECU and the ETACS-
ECU (GROUP 00 

− How to use 

Troubleshooting/inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

Code No.U0121 ABS/ASC CAN timeout

CAUTION

• If diagnosis code No. U0121 is set to the 

ETACS-ECU, always diagnose the CAN bus 
line.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

DIAGNOSTIC FUNCTION
If the signal from ABS-ECU or ASC-ECU cannot be 
received, the ETACS-ECU sets the diagnosis code 
No. U0121.

JUDGMENT CRITERIA
After the following statuses continue to be true for 5 
seconds, if the communication with the ABS-ECU or 
ASC-ECU cannot be established for 600 ms or more, 
the ETACS-ECU determines that a problem has 
occurred.

• No abnormality is present to the network.

• Ignition switch is in the ON position.

• No abnormality is present to the power supply 

fuse (IOD fuse), or the odometer value is at 80.5 
km or more.

• ETACS-ECU system voltage is at 10−16 V.

ETACS

CHASSIS ELECTRICAL

54A-523

PROBABLE CAUSES

• Malfunction of ABS-ECU

• Malfunction of ASC-ECU

• Malfunction of the ETACS-ECU

• Malfunction of the CAN bus

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 .

The diagnosis code is not set. : 

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code
Check if the diagnosis code No. U0121 is set to the 
engine ECU.

Q: Is the diagnosis code set?

YES : 

Go to Step 4.

NO : 

Go to Step 5.

STEP 4. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 ABS-ECU or ASC-ECU.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the ABS-ECU or ASC-ECU and the ETACS-
ECU (GROUP 00 

− How to use 

Troubleshooting/inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 ETACS-ECU.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the ABS-ECU or ASC-ECU and the ETACS-
ECU (GROUP 00 

− How to use 

Troubleshooting/inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

Code No.U0126 Steering wheel sensor CAN timeout

CAUTION

• If diagnosis code No. U0126 is set to the 

ETACS-ECU, always diagnose the CAN bus 
line.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

DIAGNOSTIC FUNCTION
If the signal from steering wheel sensor cannot be 
received, the ETACS-ECU sets the diagnosis code 
No. U0126.

JUDGMENT CRITERIA
After the following statuses continue to be true for 5 
seconds, if the communication with the steering 
wheel sensor cannot be established for 600 ms or 
more, the ETACS-ECU determines that a problem 
has occurred.

• No abnormality is present to the network.

• Ignition switch is in the ON position.

• No abnormality is present to the power supply 

fuse (IOD fuse), or the odometer value is at 80.5 
km or more.

• ETACS-ECU system voltage is at 10−16 V.

ETACS

CHASSIS ELECTRICAL

54A-524

PROBABLE CAUSES

• Malfunction of steering wheel sensor

• Malfunction of the ETACS-ECU

• Malfunction of the CAN bus

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. M.U.T.-III other system diagnosis code
Check if the diagnosis code No. U0126 is set to the 
AFS-ECU.

Q: Is the diagnosis code set?

YES : 

Go to Step 4.

NO : 

Go to Step 5.

STEP 4. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 steering wheel sensor.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the steering wheel sensor and the ETACS-
ECU (GROUP 00 

− How to use 

Troubleshooting/inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 ETACS-ECU.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the steering wheel sensor and the ETACS-
ECU (GROUP 00 

− How to use 

Troubleshooting/inspection Service Points 

− 

How to Cope with Intermittent Malfunction ).

Code No.U0131 EPS CAN timeout

CAUTION

• If diagnosis code No. U0131 is set to the 

ETACS-ECU, always diagnose the CAN bus 
line.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

DIAGNOSTIC FUNCTION
If the signal from EPS-ECU cannot be received, the 
ETACS-ECU sets the diagnosis code No. U0131.

JUDGMENT CRITERIA
After the following statuses continue to be true for 5 
seconds, if the communication with the EPS-ECU 
cannot be established for 600 ms or more, the 
ETACS-ECU determines that a problem has 
occurred.

• No abnormality is present to the network.

• Ignition switch is in the ON position.

• No abnormality is present to the power supply 

fuse (IOD fuse), or the odometer value is at 80.5 
km or more.

• ETACS-ECU system voltage is at 10−16 V.

ETACS

CHASSIS ELECTRICAL

54A-525

PROBABLE CAUSES

• Malfunction of EPS-ECU

• Malfunction of the ETACS-ECU

• Malfunction of the CAN bus

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 EPS-ECU.

Q: Is the diagnosis code set?

YES : 

Troubleshoot the EPS. Refer to GROUP 

37B 

− Troubleshooting .

NO : 

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code
Check if the diagnosis code No. U0131 is set to the 
engine-ECU.

Q: Is the diagnosis code set?

YES : 

Go to Step 4.

NO : 

Go to Step 5.

STEP 4. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 EPS-ECU.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the EPS-ECU and the ETACS-ECU 
(GROUP 00 

− How to use Troubleshooting/

inspection Service Points 

− How to Cope 

with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set to the 
ETACS-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 ETACS-ECU.

NO : 

The trouble can be an intermittent 
malfunction such as a poor connection or 
open circuit in the CAN bus lines between 
the EPS-ECU and the ETACS-ECU 
(GROUP 00 

− How to use Troubleshooting/

inspection Service Points 

− How to Cope 

with Intermittent Malfunction ).

Code No.U0151 SRS CAN timeout

CAUTION

• If the diagnosis code No. U0151 is set to the 

ETACS-ECU, always diagnose the CAN bus 
line.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

DIAGNOSTIC FUNCTION
If the signal from SRS-ECU cannot be received, the 
ETACS-ECU sets the diagnosis code No. U0151.

JUDGMENT CRITERIA
After the following statuses continue to be true for 5 
seconds, if the communication with the SRS-ECU 
cannot be established for 2,500 ms or more, the 
ETACS-ECU determines that a problem has 
occurred.

• No abnormality is present to the network.

• Ignition switch is in the ON position.

• No abnormality is present to the power supply 

fuse (IOD fuse), or the odometer value is at 80.5 
km or more.

• ETACS-ECU system voltage is at 10−16 V.