1997 MITSUBISHI TRITON ABS

35B-2
Bleeding 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Fluid Level Sensor Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Load Sensing Spring Length Check and
Adjustment Refer to GROUP 35A. . . . . . . . . . . . . . .
Load Sensing Proportioning Valve Function
Test Refer to GROUP 35A. . . . . . . . . . . . . . . . . . . . .
Disc Brake Pad Check and Replacement 23. . . . .
Front Disc Brake Rotor Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Lining Thickness Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Drum Inside Diameter Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake Lining and Brake Drum Connection Check
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel Speed Sensor Output Voltage Check
24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic Unit Check 26. . . . . . . . . . . . . . . . . . . . . . . .
Solenoid Valve Check 27. . . . . . . . . . . . . . . . . . . . . . .
Motor Operation Check 27. . . . . . . . . . . . . . . . . . . . . . Motor Relay and Valve Relay Continuity
Check 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remedy for a Flat Battery 28. . . . . . . . . . . . . . . . . . .
BRAKE PEDAL Refer to GROUP 35A. . . . . . . .
MASTER CYLINDER AND BRAKE
BOOSTER 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LOAD SENSING PROPORTIONING VALVE
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . .
FRONT DISC BRAKE 32. . . . . . . . . . . . . . . . . . . . .
REAR DRUM BRAKE
Refer to GROUP 35A . . . . . . . . . . . . . . . . . . . . . . . .
HYDRAULIC UNIT 37. . . . . . . . . . . . . . . . . . . . . . . . .
WHEEL SPEED SENSOR 39. . . . . . . . . . . . . . . . . .
ABS-ECU 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ABS <2WD> ± Troubleshooting35B-5
TROUBLESHOOTING35201110143
STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection Service Points.
NOTES WITH REGARD TO DIAGNOSIS
The phenomena listed in the following table are not abnormal.
PhenomenonExplanation of phenomenon
System check soundWhen starting the engine, a thudding sound can sometimes be heard coming from inside
the engine compartment, but this is because the system operation check is being
performed, and is not an abnormality.
ABS operation sound1. Sound of the motor inside the ABS hydraulic unit operation. (whine)
2. Sound is the generated along with vibration of the brake pedal. (scraping)
3. When ABS operates, sound is generated from the vehicle chassis due to repeated
brake application and release.
(Thump: suspension; squeak: tyres)
ABS operation
(Long braking distance)For road surfaces such as snow-covered roads and gravel roads, the braking distance for
vehicles with ABS can sometimes be longer than that for other vehicles. Accordingly, advise
the customer to drive safely on such roads by lowering the vehicle speed and not being too
overconfident.
Shock during system
operation checkShock may be felt when the brake pedal is depressed slightly at a low driving speed. This
occurs due to ABS operation check (initial check at a vehicle speed of 8 km/h), and does
not indicate any malfunction.
Diagnosis detection condition can vary depending on the diagnosis code.
Make sure that checking requirements listed in the ªCommentº are satisfied when checking the trouble
symptom again.
DIAGNOSIS FUNCTION35201120108
DIAGNOSIS CODES CHECK
Read a diagnosis code by the MUT-II or ABS warning lamp.
(Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.)
ERASING DIAGNOSIS CODES
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.

ABS <2WD> ± Troubleshooting35B-6
INSPECTION CHART FOR DIAGNOSIS CODES35201130156
Inspect according to the inspection chart that is appropriate for the malfunction code.
Diagnosis
code No.Inspection itemDiagnosis contentReference page
11Front right wheel speed sensorOpen or short circuit35B-7
12Front left wheel speed sensor
13Rear right wheel speed sensor
14Rear left wheel speed sensor
15Wheel speed sensorAbnormal output signal35B-8
16Power supply system35B-8
21Front right wheel speed sensorAbnormal35B-7
22Front left wheel speed sensor
23Rear right wheel speed sensor
24Rear left wheel speed sensor
33Stop lamp switch system35B-9
41Front right solenoid valve35B-10
42Front left solenoid valve
43Rear solenoid valve
51Valve relay35B-11
53Motor relay, motor35B-12
63ABS-ECU35B-41
(Replace the ABS-ECU)
64
(Re lace the ABS-ECU)

ABS <2WD> ± Troubleshooting35B-7
INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code No. 11, 12, 13, 14 Wheel speed sensor open circuit
or short circuitProbable cause
Code No. 21, 22, 23, 24 Wheel speed sensor abnormal
The ABS-ECU determines that an open circuit or short circuit occurs in more than
one line of wheel speed sensors.
Malfunction of wheel speed sensor

Malfunction of wiring harness or connector

Malfunction of ABS-ECU
These codes are output at the following times:

When an open circuit cannot be found, but more than one wheel speed sensor
does not output any signal during driving at 8 km/h or higher.

When a chipped or plugged-up rotor tooth, etc. is detected.

When the sensor output drops and anti-lock control is continuously carried out
due to a defective sensor or a warped rotor.
Malfunction of wheel speed sensor

Malfunction of rotor

Malfunction of wheel bearing

Malfunction of wiring harness or connector

Malfunction of ABS-ECU
NG
Replace the ABS-ECU.
OK
Check trouble symptoms.
OK
Check the following connector.
C-62NG
RepairOK
Wheel bearing check. (Refer to GROUP
26 and 27 ± On-vehicle Service.)
OK
Rotor check. (Refer to P.35B-40.)NGReplace the rotor.
OK
Wheel speed sensor output voltage
check. (Refer to P.35B-24.)NGWheel speed sensor check. (Refer to
P.35B-39.)NGReplace the wheel speed sensor.
OK
Measure at the ABS-ECU connectors
C-62

Disconnect the connector and
measure from the harness side.

Resistance values between 10 ± 23,
7 ± 20, 8 ± 21 and 9 ± 22.
OK: 1.2 ± 1.4 kWNGCheck the following connectors.
A-01, A-07, F-01, F-16, D-01 and C-02NG
Repair
Wheel speed sensor installation check.NG
Repair
OK
Check trouble symptoms.NGCheck the harness wire between each
wheel speed sensor and ABS-ECU, and
repair if necessary.

ABS <2WD> ± Troubleshooting35B-8
Code No. 15 Wheel speed sensor (Abnormal output signal)Probable cause
A wheel speed sensor outputs an abnormal signal (other than an open or short-circuit).
Improper installation of wheel speed sensor

Malfunction of wheel speed sensor

Malfunction of rotor

Malfunction of wheel bearing

Malfunction of wiring harness or connector

Malfunction of ABS-ECU
NG
Replace the ABS-ECU.
OK
Check trouble symptoms.
OK
Wheel bearing check. (Refer to GROUP
26 and 27 ± On-vehicle Service.)OKCheck the harness wire between each
wheel speed sensor and ABS-ECU, and
repair if necessary.
OK
Rotor check. (Refer to P.35B-40.)NGReplace the rotor.
OK
Check the following connector.
C-62NG
Repair
OK
Wheel speed sensor output voltage
check (Refer to P.35B-24.)NGWheel speed sensor check. (Refer to
P.35B-39.)NGReplace the wheel speed sensor.
Wheel speed sensor installation check.NG
Repair
Code No. 16 Power supply systemProbable cause
The voltage of the ABS-ECU power supply drops lower or rises higher than the specified
value. If the voltage returns to the specified value, this code is no longer output.
Malfunction of wiring harness or connector.

Malfunction of ABS-ECU
Caution
If battery voltage drops or rises during inspection, this code will be output as well. If the voltage
returns to standard value, this code is no longer output.
Before carrying out the following inspection, check the battery level, and refill distilled water if
necessary.
OK
Check the battery.
OK
Check trouble symptoms.NGCheck the harnes wire between the igni-
tion switch and the ABS-ECU, and repair
if necessary.
OK
Check trouble symptoms.NGReplace the ABS-ECU.
OK
Check the following connector.
C-62NG
Repair
Measure at the ABS-ECU connector
C-62.

Disconnect the connector and
measure at the harness side.

Start the engine. Voltage between
13 ± Body earth
OK:System voltageNGCheck the following connectors.
C-88, C-86 and C-02NG
Repair

ABS <2WD> ± Troubleshooting35B-9
Code No. 33 Stop lamp switch systemProbable cause
These codes are output at the following times:

When the stop lamp switch is not be turned off (when the stop lamp switch stays
on for 15 minutes or more although the ABS is not operating)

When the ABS-ECU determines that there is an open circuit in harness of the
stop lamp switch system.
Malfunction of stop lamp switch

Malfunction of harness or connector

Malfunction of ABS-ECU
OK
Check trouble symptom.
NG
Check the harness between dedicated
fuse No. 8 and the ABS-ECU, and repair
if necessary.
OK
Check the harness between dedicated
fuse No. 8 and the ABS-ECU, and repair
if necessary.
OK
Stop lamp switch check. (Refer to
GROUP 35A ± On-vehicle Service.)NGReplace the stop lamp switch.
OK
Check trouble symptom.NGReplace the ABS-ECU.
Does the stop lamp illuminate and switch
off normally?NoStop lamp switch installation check.NG
Repair
Ye s
Measure at ABS-ECU connector C-64.

Disconnect the connector and
measure at the harness side.

Stop lamp switch ON.

Voltage between 34 and body earth
OK:System voltageNGCheck the following connectors.
C-82, C-89, C-34 and C-02NG
Repair
OK
Check the following connector.
C-64NG
Repair

ABS <2WD> ± Troubleshooting35B-10
Code No. 41, 42, 43 Solenoid valveProbable cause
The ABS-ECU always monitors the solenoid valve drive circuit. It determines that
there is an open or short-circuit in the solenoid coil or in a harness: When no current
flows in the solenoid even though the ABS-ECU turns on it, and vice versa.
Malfunction of wiring harness

Malfunction of hydraulic unit

Malfunction of ABS-ECU
NG
Check the harness between the hydrau-
lic unit and ABS-ECU, and repair if nec-
essary.
OK
Check trouble symptoms.
Measure at hydraulic unit connector
A-09.

Disconnect the connector and
measure at the harness side.

Resistance values between the
following terminals
1-5, 2-5, 3-5
OK: 5.0 W
6-5, 7-5, 8-5
OK: 2.2 WNGReplace the hydraulic unit.
OK
Measure at hydraulic unit connector
A-09 and ABS-ECU connectors C-62
and C-64.

Disconnect the connector and
measure at the harness side.

Continuity between the following
terminals
OK:Continuity
HU side
ABS-ECU
side (C-64)
HU side
ABS-ECU
side (C-62)NGCheck the following connectors.
A-09, C-62 and C-64NG
Repair
OK
Measure at hydraulic unit connector
A-09 and valve relay connector A-39.

Disconnect the connector and
measure at the harness side.

Continuity between the following
terminals
OK:Continuity
HU side
Valve relay sideNGCheck the following connector and
diode.
A-09 and A-39NG
Repair
OK
Check trouble symptoms.NGCheck the harness between the hydrau-
lic unit and valve relay, and repair if nec-
essary.
OK
Check the following connectors.
C-62 and C-64NG
Repair
OK
Check trouble symptoms.NGReplace the ABS-ECU. 1
52
2
14 6
41
3
37
18
2
5
310
3

ABS <2WD> ± Troubleshooting35B-11
Code No. 51 Valve relayProbable cause
When the ignition switch is turned to ON, the ABS-ECU switches the valve relay
off and on during the initial check. In that way, the ABS-ECU compares the signals
sent to the valve relay with the voltage in the valve power monitor line. That is how
to check if the valve relay is operating normally. The ABS-ECU always checks if
current flows in the valve power monitor line, too. It determines that there is an open
circuit when no current flows. If no current flows in the valve power monitor line,
this diagnosis code is output.
Malfunction of valve relay

Malfunction of wiring harness or connector

Malfunction of ABS-ECU

Malfunction of hydraulic unit
NOTE
Whenever reading the diagnosis codes using the ABS warning lamp (Refer to GROUP 00 ± How to
Use Troubleshooting/Inspection Service Points), this diagnosis code will be output. That is not a malfunction
but because the valve relay connector is disconnected. After repairing all other malfunctions, connect
the valve relay connector again to check the valve relay. Then check that the ABS warning lamp does
not illuminate. If it illuminates, the valve relay may be defective. So carry out the following procedure.
Valve relay check. (Refer to P. 35B-28.)NGReplace the valve relay.
OK
Measure at valve relay connector A-39.

Disconnect the connector and
measure at the harness side.

Voltage between 6 ± body earth
OK:System voltageNGCheck the harness between fusible link
No. 11 and valve relay, and repair if nec-
essary.
OK
Measure at ABS-ECU connector C-62
and C-64.

Disconnect the connector and
measure at the harness side.

Resistance between 26 ± 37
OK:60 ± 120 WNGCheck the following connector.
A-39OKCheck trouble symptoms.
NG
Check the harness between valve relay
and ABS-ECU, and repair if necessary.
OK
Measure at ABS-ECU connector C-64.

Disconnect the connector and
measure at the harness side.

Continuity between 48 ± body earth
OK:ContinuityNGCheck the harness between the valve
relay and ABS-ECU, and repair if neces-
sary.
OK
Check the following connector.
C-64OKCheck trouble symptoms.NGReplace the ABS-ECU.