Mitsubishi Outlander GS45X. Manual — part 363

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-73

Past trouble

• When the diagnostic trouble code No. C100A is also set,

carry out diagnosis with particular emphasis on wiring har-
ness and connector failures between ABS-ECU and the
wheel speed sensor. For diagnosis procedures, refer to
How to treat past trouble (GROUP 00

− How to Use Trou-

bleshooting/How to Treat Past Trouble

P.00-17

).

• When the diagnostic trouble code No. C100A is not set, the

following conditions may be present:

• Some wheels slip.

• Unstable vehicle attitude

• External noise interference

• Vehicle ran with the parking brake applied.

• Only two wheels are rotated on a drum tester.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus
lines.
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 3.
NO : Repair the CAN bus lines (Refer to GROUP 54C

−

CAN Bus Diagnostics Table

P.54C-17

). On

completion, go to Step 2.

STEP 2. DTC recheck after resetting CAN bus lines
Q: Is DTC C1041 set?

YES : Go to Step 3.
NO : The procedure is complete.

STEP 3. Using scan tool MB991958, check the DTC
Check that the DTC C100A is also set.
Q: Is DTC C100A also set?

YES : Perform the diagnosis for the DTC C100A (Refer to

P.35B-17

).

NO : Go to Step 4.

STEP 4. Check wheel speed sensor <FL> installation
Check how the wheel speed sensor <FL> is installed (Discon-
nection of wheel speed sensor <FL>, loose mounting bolt,
etc.).
Q: Is the check result normal?

YES : Go to Step 5.
NO : Reinstall the wheel speed sensor <FL> correctly

(Refer to

P.35B-189

). Then go to Step 5.

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-74

STEP 5. Check for wheel speed sensor <FL> output
current
Refer to

P.35B-184

.

Q: Is the check result normal?

YES : Go to Step 6.
NO : Replace the wheel speed sensor <FL> (Refer to

P.35B-189

). Then go to Step 9.

STEP 6. Check for wheel bearing looseness
NOTE:

.

•

Loose wheel bearing may increase the gap between the
wheel speed sensor <FL> and the wheel speed detection
magnet encoder.

•

Check the wheel bearing <FL> for looseness (Refer to
GROUP 26

−

Wheel Bearing Play Check

P.26-11

).

Q: Is the check result normal?

YES : Go to Step 7.
NO : Replace the wheel bearing <FL> (Refer to GROUP 26

− Front Axle Hub Assembly

P.26-13

). Then go to Step

10.

STEP 7. Check wheel speed detection encoder
Check the encoder for adhesion of foreign materials or defor-
mation.
Q: Is the check result normal?

YES : Go to Step 8.
NO (Adhesion of foreign materials) : Remove the foreign

materials and clean the encoder so as not to disturb
the magnetization pattern on it while taking care of the
magnet, magnetic substance, and magnetic
attraction. Then go to Step 10.

NO (Deformation) : Replace the wheel bearing <FL>

(Refer to GROUP 26

− Front Axle Hub Assembly

P.26-13

). Then go to Step 10.

STEP 8. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Drive the vehicle at 12mph (20 km/h) or higher.

NOTE: The ABS warning light does not turn OFF in some
cases unless the vehicle runs at 12mph (20 km/h) or higher.

Q: Is DTC C1041 set?

YES : Replace the wheel speed sensor <FL> (Refer to

P.35B-189

). Then go to Step 9.

NO : Intermittent malfunction (Refer to GROUP 00

− How

to Use Troubleshooting/How to Cope with Intermittent
Malfunctions

P.00-15

).

AC608761

Oil seal

Magnetic
encoder

Wheel
bearing

AB

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-75

STEP 9. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Drive the vehicle at 12mph (20 km/h) or higher.

NOTE: The ABS warning light does not turn OFF in some
cases unless the vehicle runs at 12mph (20 km/h) or higher.

Q: Is DTC C1041 set?

YES : Replace the hydraulic unit (integrated with ABS-ECU)

(Refer to

P.35B-188

). Then go to Step 10.

NO : The procedure is complete.

STEP 10. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Drive the vehicle at 12mph (20 km/h) or higher.

NOTE: The ABS warning light does not turn OFF in some
cases unless the vehicle runs at 12mph (20 km/h) or higher.

Q: Is DTC C1041 set?

YES : Return to Step 1.
NO : The procedure is complete.

DTC C1042: Abnormality in periodical signal for FR wheel speed sensor

CAUTION

• If there is any problem in the CAN bus lines, an incor-

rect DTC may be set. Prior to this diagnosis, diagnose
the CAN bus lines (Refer to GROUP 54C

− CAN Bus

Line Diagnostic Flow

P.54C-10

).

• Whenever ECU is replaced, ensure that the CAN bus

lines are normal.

.

CIRCUIT OPERATION

• The wheel speed sensor is a kind of a pulse generator. It

consists of encoders (a plate on which north and south pole
sides of the magnets are arranged alternately) for detecting
the wheel speed which rotates at the same speed of the
wheels and wheel speed sensors. This sensor outputs fre-
quency pulse signals in proportion to the wheel speed.

• The pulse signals, which the wheel speed sensor creates,

are sent to ABS-ECU. ABS-ECU uses the frequency of the
pulse signals to determine the wheel speed.

.

DTC SET CONDITIONS

ASC-ECU monitors the signals from each wheel speed sensor
while the vehicle is being driven. If any periodical drop is found
in these sensor signals, ASC-ECU will set the relevant DTC.

.

ABS DIAGNOSIS

TSB Revision

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-76

PROBABLE CAUSES

Current trouble

• Excessive gap between the wheel speed sensor and the

magnetic encoder for wheel speed detection

• Wheel bearing malfunction

• Deformation of the magnetic encoder for wheel speed

detection

• Adhesion of foreign materials on the wheel speed sensor

• Adhesion of foreign materials on the magnetic encoder for

wheel speed detection

• Malfunction of wheel speed sensor

• Improper installation of the wheel speed sensor

• ABS-ECU malfunction

• Disturbance of magnetization pattern for magnetic encoder

for wheel speed detection

• The number of poles on the magnetic encoder for wheel

speed detection (the number of N-pole and S-pole) is
changed.

Past trouble

• When the diagnostic trouble code No. C1015 is also set,

carry out diagnosis with particular emphasis on wiring har-
ness and connector failures between ABS-ECU and the
wheel speed sensor. For diagnosis procedures, refer to
How to treat past trouble (GROUP 00

− How to Use Trou-

bleshooting/How to Treat Past Trouble

P.00-17

).

• When diagnostic trouble code No. C1015 is not set, the fol-

lowing conditions may be present:

• Some wheels slip.

• Unstable vehicle attitude

• External noise interference

• Vehicle ran with the parking brake applied.

• Only two wheels are rotated on a drum tester.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus
lines.
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 3.
NO : Repair the CAN bus lines (Refer to GROUP 54C

−

CAN Bus Diagnostics Table

P.54C-17

). On

completion, go to Step 2.