Mitsubishi 380. Manual - part 950

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-25

STEP 15. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the DTC is reset.
(6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1200, C1205, C1210 or C1215 set?

YES : Replace the hydraulic unit (integrated with

ABS-ECU). Then go to Step 16.

NO : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-14

STEP 16. Recheck for diagnostic trouble code.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the DTC is set.
(6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1200, C1205, C1210 or C1215 set?

YES : Repeat the troubleshooting from Step 1.
NO : The procedure is complete.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-26

DTC C1201/C1206/C1211/1216 Wheel Speed Sensor (Abnormal Output Signal). (C1225) Deviation in
wheel speed. This code may also be set, togethor with other codes.

CAUTION

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.

NOTE: If the ABS-8 ECU or the active wheel
speed sensor are disconnected, or if the wiring is
an open/ short circuit, the ABS 8 ECU will shut
off power supply to the respective wheel speed
sensor. All other wheel speed sensors will oper-
ate normally. To restore the power supply, the
ignition switch must be turned to the "OFF" posi-
tion then to the "ON" position again.

CIRCUIT OPERATION

• Active wheel speed sensors have been installed,

that produce changes of current flow through the
wheel speed sensor circuit which is influenced by
the reluctor ring fitted to the wheel hub.

• Active wheel speed sensors have a constant

incoming power supply on one wire and return a
signal on the other wire

• The advantage of the active wheel speed sensor

is that there is always a signal until the wheel
has stopped. As the wheel speeds up or slows
down, the frequency will change where the ampli-
tude of the signal will remain constant.

• A Hall switch and magnet assembly is contained

within the sensor.

• As the tooth on the reluctor approaches the sen-

sor, the magnetic circuit is completed therefore
turning on the Hall switch. As the tooth departs
the sensor, the Hall switch will turn off.

• The output waveform displayed on the oscillo-

scope will be a square wave, (between signal
wire and ground).

• The ABS hydraulic unit modulates the amount of

braking force individually applied to each wheel
cylinder.

35DB090A

35DB033A

CONNECTOR: C-25

C-25

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-27

ABS DTC SET CONDITIONS

The 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, the ECU
will set the relevant diagnostic trouble code.

• Missing sensor signal

• Sensor signal, which will not be created under

normal operation

• Significant difference among the wheel speed

sensor signals

NOTE: DTC C1225 may also be set with the abnor-
mal wheel speed sensor codes as it too looks for a
variation in wheel speeds that does not meet crite-
ria.It is possible for DTC C1125 to be logged by itself,
"during an extended wheel spin" and only be stored
as a history code and no action is required.

TROUBLESHOOTING HINTS (The most
likely causes for these DTCs are to set
are:)

Current trouble

• Malfunction of the wheel speed sensor or wheel

speed rotor

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit (integrated with

ABS-ECU)

Past trouble

• Carry out diagnosis with particular emphasis on

connector(s) or wiring harness in wheel speed
sensor circuit. For diagnosis procedures, refer to
"How to cope with past trouble" (Refer to GROUP
00, How to use Troubleshooting/Inspection Ser-
vice Points

P.00-16

Circuit drawings

• Refer to circuit diagrams GROUP-

• Refer to configuration diagrams GROUP-

Past trouble

For diagnosis procedures, refer to "How to cope with
past trouble" (Refer to GROUP 00, How to Use Trou-
bleshooting

P.00-16

DIAGNOSIS

Required Special Tools:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

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

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

• MB991219: Inspection Test Harness

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-28

STEP 1. Using diagnostic tool MB991958, diagnose the
CAN bus line.

CAUTION

To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Connect diagnostic tool MB991958 to the data link

connector.

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

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

Diagnosis

P.54C-15

). Then go to Step 2.

STEP 2. Recheck for diagnostic trouble code.

CAUTION

To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the DTC is set.
(6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1201, C1206, C1211 or C1216 set?

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

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

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