Mitsubishi Lancer Evolution IX. Manual - part 583

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-15

PROBABLE CAUSES

• Malfunction of the wheel speed sensor

• Damaged harness wires and connectors

• Malfunction of the ABS-ECU

• Malfunction of the 4WD-ECU

DIAGNOSIS

STEP 1. M.U.T.-II/III diagnosis code

Q: Are ABS diagnosis codes 11, 12, 13, 14, 21, 22, 23, 

24 set?
YES : 

Refer to GROUP 35B 

− Check Chart for 

Diagnosis Codes 

P.35B-9

.

NO : 

Go to Step 2.

STEP 2. M.U.T.-II/III data list

• Item 01: Wheel speed sensor <FR>

• Item 02: Wheel speed sensor <FL>

• Item 03: Wheel speed sensor <RR>

• Item 04: Wheel speed sensor <RL>

Check the above data list (Refer to data list reference 
table 

P.22A-142

).

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Cope with Intermittent 

Malfunction 

P.00-5

).

NO : 

Go to Step 3.

STEP 3. Measure the voltage at 4WD-ECU 
connector C-25.
(1) Turn the ignition switch to the ON position.

(2) Measure the voltage between the following 

terminals of 4WD-ECU connector C-25 and earth 
while turning the relevant tyre of the terminal 
being measured one-half to one turn per second.

• Terminal No.9 <FR>

• Terminal No.6 <FL>

• Terminal No.7 <RR>

• Terminal No.8 <RL>

OK: 0 

⇔ 5 V flushing

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Go to Step 4.

AC311002

4WD-ECU

Harness side

C-25 (Y)

AB

Connector: C-25

4WD-ECU

C-25 (Y)

Rear console 
assembly

<LH drive vehicles>

<RH drive vehicles>

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-16

STEP 4. Connectors check: B-118 ABS-ECU 
connector, C-25 4WD-ECU connector.

Check for the contact with terminals.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the defective connector.

AC311020

Harness side

B-118 
(B)

AB

Connector: B-118

<LH drive vehicles>

<RH drive vehicles>

B-118 
(GR)

B-118

AC311002

4WD-ECU

Harness side

C-25 (Y)

AB

Connector: C-25

4WD-ECU

C-25 (Y)

Rear console 
assembly

<LH drive vehicles>

<RH drive vehicles>

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-17

STEP 5. Check the harness between ABS-ECU 
connector B-118 (terminal No.9, 6, 7, 8) and 
4WD-ECU connector C-25 (terminal No.18, 32, 21, 
20).

Check the output line for short or open circuit.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the wiring harness.

STEP 6. M.U.T.-II/III data list

• Item 01: Wheel speed sensor <FR>

• Item 02: Wheel speed sensor <FL>

• Item 03: Wheel speed sensor <RR>

• Item 04: Wheel speed sensor <RL>

Check the above data list (Refer to data list reference 
table 

P.22A-142

).

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Cope with Intermittent 

Malfunction 

P.00-5

).

NO : 

Replace the 4WD-ECU.

STEP 7. Connector check: C-25 4WD-ECU 
connector.

Check for the contact with terminals.

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Repair the defective connector.

AC311020

Harness side

B-118 
(B)

AB

Connector: B-118

<LH drive vehicles>

<RH drive vehicles>

B-118 
(GR)

B-118

AC311002

4WD-ECU

Harness side

C-25 (Y)

AB

Connector: C-25

4WD-ECU

C-25 (Y)

Rear console 
assembly

<LH drive vehicles>

<RH drive vehicles>

AC311002

4WD-ECU

Harness side

C-25 (Y)

AB

Connector: C-25

4WD-ECU

C-25 (Y)

Rear console 
assembly

<LH drive vehicles>

<RH drive vehicles>

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-18

Code No.25 Wrong-diameter tyre

ABS SIGNAL LINE SYSTEM CIRCUIT

Refer to 

P.22A-14

.

OPERATION

The 4WD-ECU receives each wheel speed sensor 
signal through the ABS-ECU to detect the tyre condi-
tions.

DIAGNOSIS CODE SET CONDITIONS

Code No.25 is set as wrong-diameter tyre when one 
of the four vehicle speeds is outside the range of 
specified values in respect to the average of the four 
vehicle speed sensors, when the vehicle speed is 
above 20 km/h with the steering wheel in the straight 
ahead position. However the warning lamp does not 
light up.

PROBABLE CAUSES

• Malfunction of the tyre

• Malfunction of the wheel speed sensor

• Damaged harness wires and connectors

• Malfunction of the ABS-ECU

• Malfunction of the 4WD-ECU

DIAGNOSIS

STEP 1. Check the tyre.
Check the tyre pressure, size and brand.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Adjust or replace the tyre.

STEP 2. M.U.T.-II/III diagnosis code

Q: Are ABS diagnosis codes 11, 12, 13, 14, 21, 22, 23, 

24 set?
YES : 

Refer to GROUP 35B 

− Check Chart for 

Diagnosis Codes 

P.35B-9

.

NO : 

Go to Step 3.

STEP 3. M.U.T.-II/III diagnosis code

Q: Are ACD diagnosis codes 21, 22, 23, 24 set?

YES : 

Refer to diagnosis code 21, 22, 23, 24 

Wheel Speed Sensor System 

P.22A-14

.

NO : 

Go to Step 4.

STEP 4. M.U.T.-II/III data list

• Item 01: Wheel speed sensor <FR>

• Item 02: Wheel speed sensor <FL>

• Item 03: Wheel speed sensor <RR>

• Item 04: Wheel speed sensor <RL>

Check the above data list (Refer to data list reference 
table 

P.22A-142

).

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Cope with Intermittent 

Malfunction 

P.00-5

).

NO : 

Replace the 4WD-ECU.