Mitsubishi Lancer Evolution IX. Manual - part 584

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-19

Code No.26 Wheel speed sensor system (faulty output signal)

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 conditions 
of the wheel speed sensors.

DIAGNOSIS CODE SET CONDITIONS

Code No.26 is set as output signal error of the wheel 
speed sensor when one wheel speed is outside the 
specified range at the vehicle speed of above 20 
km/h. However, warning lamp will 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.

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-20

Code No.31 Steering wheel sensor system <ST-1, ST-2, ST-N>

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue
W : White     Y : Yellow     SB : Sky blue     BR : Brown
O : Orange     GR : Gray     R : Red     P : Pink     V : Violet

IGNITION
SWITCH (IG2)

4WD-ECU

STEERING
WHEEL
SENSOR

Steering wheel sensor system circuit <LH drive vehicles>

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-21

OPERATION

The steering wheel sensor detects the neutral posi-
tion and steering angle of the steering wheel by the 
photointerruptor (ST-1, ST-2 or ST-N), and sends 
them to the 4WD-ECU.

DIAGNOSIS CODE SET CONDITIONS

Code No.31 is set when open circuit or short circuit 
of the steering wheel sensor output line (ST-1, ST-2, 
or ST-N) occurs.

PROBABLE CAUSES

• Malfunction of the steering wheel sensor

• Damaged harness wires and connectors

• Malfunction of the 4WD-ECU

DIAGNOSIS

STEP 1. M.U.T.-II/III diagnosis code

Q: Are ABS diagnosis codes 81, 82, 83 set?

YES : 

Go to Step 8.

NO : 

Go to Step 2.

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue
W : White     Y : Yellow     SB : Sky blue     BR : Brown
O : Orange     GR : Gray     R : Red     P : Pink     V : Violet

IGNITION
SWITCH (IG2)

4WD-ECU

STEERING
WHEEL
SENSOR

Steering wheel sensor system circuit <RH drive vehicles>

TROUBLESHOOTING <ACD>

MANUAL TRANSMISSION (FF)

22A-22

STEP 2. M.U.T.-II/III data list

• Item 21: Steering wheel sensor voltage <ST-1>

• Item 22: Steering wheel sensor voltage <ST-2>

• Item 23: Steering wheel sensor voltage <ST-N>

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-26.
(1) Turn the ignition switch to the ON position.

(2) Measure the voltage between the following 

terminals of 4WD-ECU connector C-26 and earth 
while turning the steering wheel.

• Terminal No.33 <ST-1>

• Terminal No.34 <ST-2>

• Terminal No.44 <ST-N>

OK: Approximately 1.5 

⇔ 3.5 V flushing

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Go to Step 6.

STEP 4. Connector check: C-26 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.

STEP 5. M.U.T.-II/III data list

• Item 21: Steering wheel sensor voltage <ST-1>

• Item 22: Steering wheel sensor voltage <ST-2>

• Item 23: Steering wheel sensor voltage <ST-N>

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.

AC311002

4WD-ECU

Harness side

C-26 (Y)

AC

Connector: C-26

4WD-ECU

C-26 (Y)

Rear console 
assembly

<LH drive vehicles>

<RH drive vehicles>

AC311002

4WD-ECU

Harness side

C-26 (Y)

AC

Connector: C-26

4WD-ECU

C-26 (Y)

Rear console 
assembly

<LH drive vehicles>

<RH drive vehicles>