Mitsubishi Outlander XL. Manual — part 619

YES:

The short circuit in the wheel speed sensor <FR>

circuit may be present. Repair the wiring harness between
the A-01 ABS-ECU connector terminal No. 22/21 and the A-59
wheel speed sensor <FR> connector terminal No. 1/2.

NO:

Repair the defective connector.

STEP 11. Voltage measurement at the A-01 ABS-ECU
connector

ZC601292 0007

ABS-ECU

MB991974

Check harness

A-01 ABS-ECU
harness connector

(1)

Disconnect the ABS-ECU connector, connect special tool
MB991974 to the ABS-ECU-side connector and harness-
side connector, and then measure the voltage at the special
tool connector side.

(2)

Turn the ignition switch to the ON position.

(3)

Measure the voltage between the wheel speed sensor circuit
power supply terminal (signal terminal) No. 22 and the body
ground.

OK: Approximately battery voltage

Q:Is the check result normal?

YES:

Go to Step 14.

NO:

Go to Step 12.

STEP 12. Connector check: A-01 ABS-ECU connector, A-59
wheel speed sensor <FR> connector

Q:Is the check result normal?

YES:

Go to Step 13.

NO:

Repair the defective connector.

STEP 13. Wiring harness check between A-01 ABS-ECU
connector terminal No. 22/21 and A-59 wheel speed sensor
<FR> connector terminal No. 1/2

｠

Check for the open circuit in the wheel speed sensor <FR>
circuit.

Q:Is the check result normal?

YES:

Replace the wheel speed sensor.

NO:

Repair the wiring harness.

STEP 14. Check whether the diagnostic trouble code is
reset.

(1)

Erase the diagnostic trouble code.

(2)

Drive the vehicle at 12mph (20 km/h) or more.

NOTE:

The ABS warning light does not turn OFF in some

cases unless the vehicle runs at 12mph (20 km/h) or
higher.

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-39

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

Q:Is DTC C101C set?

YES:

Replace the ABS-ECU.

NO:

Intermittent malfunction (GROUP 00 - How to Cope with

Intermittent Malfunction P.00-15).

DTC C1027: Abnormality in RL wheel speed sensor signal

M13502000913USA0000010000

Wheel Speed Sensor Circuit

ABS-ECU

(LH)

(LH)

(RH)

(RH)

FRONT WHEEL SPEED SENSOR

REAR WHEEL SPEED SENSOR

If there is any problem in the CAN bus lines, an incorrect
diagnostic trouble code may be set. Prior to this diagnosis,
diagnose the CAN bus lines. (Refer to GROUP 54D, Trouble
code diagnosis P.54D-17).

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
frequency 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.

35B-40

ANTI-LOCK BRAKING SYSTEM (ABS)

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

DTC SET CONDITIONS
ABS-ECU monitors the signals from each wheel speed sensor
while the vehicle is being driven. If any fault below is found in
these sensor signals, ABS-ECU will set the relevant diagnostic
trouble code.

｠

Irregular change in the wheel speed sensor signal

｠

Wheel speed sensor signal continuously indicates high value.

PROBABLE CAUSES

Current trouble

｠

Excessive gap between the wheel speed sensor and the
wheel speed detection encoder

｠

Adhesion of foreign materials on the wheel speed sensor

｠

Adhesion of foreign materials on the wheel speed detection
encoder

｠

Wheel bearing malfunction

｠

Malfunction of wheel speed sensor

｠

Damaged wiring harness and connectors

｠

External noise interference

｠

Improper installation of the wheel speed sensor

｠

Deformation of the wheel speed detection encoder

｠

ABS-ECU malfunction

｠

Disturbance of magnetization pattern for wheel speed
detection encoder

Past trouble

｠

When the diagnostic trouble code No. C1020 is also set, carry
out diagnosis with particular emphasis on wiring harness and
connector failures between ABS-ECU and the wheel speed
sensor. For diagnosis procedures, refer to How to treat past
trouble (Refer to GROUP 00 - How to Cope with Intermittent
Malfunction P.00-15).

｠

When the diagnostic trouble code No. C1020 is not set, the
following conditions may be present:

｠

Right or/and left wheels are rotated.

｠

Unstable vehicle attitude

｠

External noise interference

｠

Vehicle ran with the parking brake applied.

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

｠

MB991974: ABS check harness

STEP 1. M.U.T.-III CAN bus diagnostics
Use scan tool to diagnose the CAN bus lines.

Q:Is the check result normal?

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-41

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

YES:

Go to Step 3.

NO:

Repair the CAN bus lines. (Refer to GROUP 54D - CAN

Bus Diagnostics table P.54D-17.) On completion, go to
Step 2.

STEP 2. Diagnostic trouble code recheck after resetting
CAN bus lines

Q:Is DTC C1027 set?

YES:

Go to Step 3.

NO:

The procedure is complete.

STEP 3. M.U.T.-III diagnostic trouble code
Check that the diagnostic trouble code C1020 is also set.

Q:Is DTC C1020 also set?

YES:

Perform the diagnosis for the diagnostic trouble

code C1020. (Refer to P.35B-20.)

NO:

Go to Step 4.

STEP 4. Check for wheel speed sensor installation
Check how the wheel speed sensor <RL> is installed
(Disconnection of wheel speed sensor, loose mounting bolt,
etc.).

Q:Is the check result normal?

YES:

Go to Step 5.

NO:

Reinstall the wheel speed sensor <RL> correctly.

STEP 5. Check for wheel speed sensor as a single unit

Q:Is the check result normal?

YES:

Go to Step 6.

NO:

Replace the wheel speed sensor.

STEP 6. Check for wheel bearing looseness

NOTE:

Loose wheel bearing may increase the gap between the

wheel speed sensor and the wheel speed detection magnet
encoder. Check the wheel bearing <RL> for looseness. <Refer
to GROUP 27A - On-vehicle Service P.27A-4.(FWD) or GROUP 27B
- On-vehicle Service P.27B-15.(AWD)>

Q:Is the check result normal?

YES:

Go to Step 7.

NO:

Replace the rear wheel hub assembly.

35B-42

ANTI-LOCK BRAKING SYSTEM (ABS)

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS