Mitsubishi Lancer Evolution IX. Manual — part 518

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-103

INSPECTION PROCEDURE 6: The Neutral Position Learning of the Steering Wheel Sensor is not
Detected.

CIRCUIT OPERATION

The ABS system detects the neutral position learning
of the steering wheel sensor by the signal from the
stop lamp.

COMMENT ON TROUBLE SYMPTOM

The diagnosis is difficult because it depends on driv-
ing condition and road surface, if the diagnosis code
has not been set, carry out the following checks
(refer to TROUBLESHOOTING HINTS).

IGNITION
SWITCH (IG2)

STEERING
WHEEL
SENSOR

ABS-ECU

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

ST-1

ST-2

ST-N

Steering Wheel Sensor Circuit

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-104

PROBABLE CAUSES

The most likely causes for this case are:

• Damaged wiring harness or connector

• Malfunction of the stop lamp switch system

• Tyres are not all the same diameter

• Malfunction of suspension

• Malfunction of the steering wheel sensor installa-

tion

• Malfunction of the brake modulator hydraulic unit

(integrated with ABS-ECU)

DIAGNOSIS

STEP 1. Check the front tyres.

Q: Are the tyre diameters different?

YES :

Replace the appropriate tyre and then go to

Step 13.

NO :

Go to Step 2.

STEP 2. Check the front suspension.

Q: Is the front suspension abnormal?

YES :

Repair the front suspension and then go to

Step 13.

NO :

Go to Step 3.

STEP 3. M.U.T.-II/III data list.

CAUTION

To prevent damage to M.U.T.-II/III, always turn the
ignition switch to the "LOOK" (OFF) position
before connecting or disconnecting M.U.T.-II/III.

(1) Connect M.U.T.-II/III as shown in the illustration.
(2) Start the engine.

AC207179AB

M.U.T.-II

16-PIN

<Using the M.U.T.-II>

AC210056

AC

MB991911

16-PIN

MB991827

MB991824

<Using the M.U.T.-III>

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-105

(3) Set M.U.T.-II/III to data reading mode for following

item.

• Item No.37: Steering wheel sensor neutral

position learning

OK:

Q: Is the steering wheel sensor straight ahead

position learning input normal?
YES :

Go to Step 5.

NO :

Confirm the steering wheel sensor is
correctly installed. Then go to Step 4.

STEP 4. Check for steering wheel sensor output
voltage.

(1) Connect steering wheel sensor connector C-230.

(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage, by backprobing, between

terminal 1 and earth, terminal 4 and earth, and
terminal 5 and earth.

OK: The voltage should measure as indi-
cated in the figure.

Q: Is the steering wheel sensor output voltage

normal?
YES :

Go to Step 13.

NO :

Replace the steering wheel sensor (Refer to

P.35B-150

). and then go to Step 13.

STEP 5. Check the stop lamp.

Q: Does the stop lamp turn on and off normally?

YES :

Go to Step 9.

NO :

Go to Step 6.

STEP 6. Check the stop lamp switch installation
condition.

Q: Is the stop lamp switch installed correctly?

YES :

Check the stop lamp switch (Refer to

GROUP 35A, Brake pedal

P.35A-15

). Then

go to Step 7.

NO :

Repair the installation of the stop lamp
switch (Refer to GROUP 35A, On-vehicle
Service - Brake pedal Check and
Adjustment

P.35A-5

). Then go to Step 13.

Checking requirement

Display

After driving straight at vehicle
speed over than 10 km/h

ON

Before driving with ignition switch
ON

OFF

AC212249AD

Connector: C-230

Connector C-230
(Harness side)

5 4

1
2

3

AC211894

Time

AB

Voltage

2.7 - 4.4 V

0.8 - 2.1 V

Variations in voltage when turning the
steering wheel

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-106

STEP 7. Check the following connectors.

•

Intermediate connectors C-129

• Stop lamp switch connector C-102

Check the connectors for loose, corroded or dam-
aged terminals, or terminals pushed back in the con-
nector.

Q: Are the connectors and terminals in good

condition?
YES :

Go to Step 8.

NO :

Repair it and then go to Step 13.

STEP 8. Check the following harness wires.

•

The wire between relay box in engine compartment

(fuse No.10) and stop lamp switch connector
C-102 (terminal 2)

• The wire between stop lamp switch connector

C-102 (terminal 1) and stop lamps

Q: Is any harness wire damaged?

YES :

Repair or replace it and then go to Step 13.

NO :

Go to Step 9.

AC212218AH

Connectors: C-102, C-129

C-102

C-129

4

1

2

3

Connector C-102
(harness side)

18

3

16

15

14

1 2

17

4 5

8

20

19

6 7

2122

9 10

25

13

24

23

12

11

Connector C-129

AC208825AN

Fuse: No.10

No.10

AC211265DH

Connector: C-102

C-102

4

1

2

3

Harness side