1997 MITSUBISHI TRITON ECU

ABS <2WD> ± Troubleshooting35B-17
Inspection Procedure 5
When ignition key is turned to ºSTARTº, ABS warning
lamp does not illuminate.
Probable cause
Current does not flow in the ABS-ECU when the ignition switch is turned to START.
Current flows in the ABS warning lamp even when the ignition switch is turned to
START. Therefore, the valve relay, which current is supplied through the ABS-ECU,
turns off when the ignition switch is at START. However, the warning lamp circuit
of the valve relay must turn on in turn. So the cause must be a defective circuit
on valve relay side.
Malfunction of wiring harness or connector

Malfunction of ABS-ECU
ABS valve relay check (Refer to
P.35B-28.)NGReplace the ABS valve relay.
OK

Disconnect valve relay connector
A-39.

Disconnect ABS-ECU connector
C-64.

Ignition switch: ON

Voltage between valve relay
harness-side connector terminal (3)
and body earth
OK:System voltageNGCheck the following connector and
diode.
C-02 and C-05NG
Repair
OK
Check trouble symptoms.NGCheck the harness between the com-
bination meter and valve relay, and re-
pair if necessary.
OK
Check the following connector.
A-39NG
Repair
OK
Check trouble symptoms.NGCheck the harness between the valve
relay and earth, and repair if necessary.
Inspection Procedure 6
The ABS warning lamp flashes twice after the ignition key
is turned to ºONº. The lamp illuminates when the ignition
key is turned to ºSTARTº, and when the key is returned to
ºONº, it flashes once.
Probable cause
The ABS-ECU causes the ABS warning lamp to illuminate during the initial check
(approx. 3 seconds). During the initial check, the valve relay turns from off to on,
off and back to on again. If there is an open circuit in the harness between the ABS-ECU
and the ABS warning lamp, the lamp will illuminate only when the valve relay is OFF
during valve relay test, etc.
Malfunction of wiring harness or connector

Malfunction of ABS-ECU

Disconnect valve relay connector
A-39.

Disconnect ABS-ECU connector
C-64.

Ignition switch: ON

Voltage between ABS-ECU har-
ness-side connector terminal (50)
and body earth
OK:System voltageNGCheck the following connector.
C-02NG
Repair
OK
Check trouble symptom.NGCheck the harness between the com-
bination meter and the ABS-ECU, and
repair if necessary.
OK
Check the following connector.
C-64NG
Repair
OK
Check trouble symptom.NGReplace the ABS-ECU.

ABS <2WD> ± Troubleshooting35B-18
Inspection Procedure 7
Brake operation is abnormal.
Probable cause
This varies depending on the driving conditions and the road surface conditions, so
problem diagnosis is difficult. However, if a normal diagnosis code is displayed, carry
out the following inspection.
Improper installation of wheel speed sensor

Incorrect sensor harness contact

Foreign material adhering to wheel speed sensor

Malfunction of wheel speed sensor

Malfunction of rotor

Malfunction of wheel bearing

Malfunction of hydraulic unit

Malfunction of ABS-ECU
OK
Check trouble symptom.NGReplace the ABS-ECU.
OK
Check the following connector.
C-62NG
Repair
NG
Measure at ABS-ECU connector C-62.

Disconnect the connector and
measure at the harness side.

Resistance value between terminals
10-23, 7-20, 8-21 and 9-22
OK:1.2 ± 1.4 kW
(The sensor harness and connector
should be moved while these
inspections are carried out.)NG
Repair
OK
Check trouble symptom.
OK
Check the following connectors.
A-01, A-07, F-01, F-16, D-01, and C-02NG
Repair
OK
Wheel bearing check. (Refer to GROUP
26 and 27 ± On-vehicle Service.)NG
Repair
OK
Rotor check. (Refer to P.35B-40.)NGReplace the rotor.
OK
Hydraulic unit check. (Refer to P.
35B-26.)
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

35C-2
For the items below, refer to GROUP
35A.
SEALANTS
ON-VEHICLE SERVICE
Brake Pedal Check and Adjustment
Stop Lamp Switch Inspection
Brake Booster Operating Test
Check Valve Operation Check
Brake Booster Vacuum Switch Check
Load Sensing Spring Length Check and
Adjustment
Load Sensing Proportioning Valve Function
Test
Front Disc Brake Rotor Check
Brake Lining Thickness Check
Brake Drum Inside Diameter Check
Brake Lining and Brake Drum Connection
Check
BRAKE PEDAL
LOAD SENSING PROPORTIONING VALVE
REAR DRUM BRAKE
For the items below, refer to GROUP
35B.
ON-VEHICLE SERVICE
Bleeding
Disc Brake Pad Check and Replacement
Wheel Speed Sensor Output Voltage Check
Hydraulic Unit Check
Solenoid Valve Check
Motor Operation Check
Motor Relay and Valve Relay Continuity Check
Remedy for a Flat Battery
MASTER CYLINDER AND BRAKE
BOOSTER
HYDRAULIC UNIT
ABS-ECU

ABS <4WD> ± Troubleshooting35C-6
INSPECTION CHART FOR DIAGNOSIS CODES35201130163
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 circuitRefer to GROUP 35B ± Troubleshooting.
12Front left wheel speed sensor
13Rear right wheel speed sensor
14Rear left wheel speed sensor
15Wheel speed sensorAbnormal output signalRefer to GROUP 35B ± Troubleshooting.
16Power supply systemRefer to GROUP 35B ± Troubleshooting.
21Front right wheel speed sensorAbnormalRefer to GROUP 35B ± Troubleshooting.
22Front left wheel speed sensor
23Rear right wheel speed sensor
24Rear left wheel speed sensor
25Free wheel engage switch35C-7
264WD position detection switch35C-8
27Rear differential lock detection switch35C-9
32G-sensor system35C-10
33Stop lamp switch systemRefer to GROUP 35B ± Troubleshooting.
41Front right solenoid valveRefer to GROUP 35B ± Troubleshooting.
42Front left solenoid valve
43Rear solenoid valve
51Valve relayRefer to GROUP 35B ± Troubleshooting.
53Motor relay, motorRefer to GROUP 35B ± Troubleshooting.
63ABS-ECURefer to GROUP 35B ± ABS-ECU.
(Replace the ABS-ECU )
64
(Re lace the ABS-ECU.)

ABS <4WD> ± Troubleshooting35C-7
INSPECTION PROCEDURE CLASSIFIED BY DIAGNOSIS CODES
For diagnosis code numbers other than those listed below, refer to GROUP 35B ± Troubleshooting.
Code No. 25 Free wheel engage switch
Probable cause
ABS-ECU determines that an open circuit exists in the free wheel engage switch
system.
Malfunction of wiring harness or connector

Malfunction of 4WD indicator-ECU

Malfunction of ABS-ECU
Does the 4WD indicator lamp operate
normally?No4WD indicator-ECU check. (Refer to
GROUP 22 ± 4WD indicator-ECU.)NGReplace the 4WD indicator-ECU.
Ye s
Measure at ABS-ECU connector C-64.

Disconnect the connector and
measure at the harness side.

Ignition switch ON

Voltage between 45 and body earth
OK:System voltage 2WD> or 0 V NGCheck the following connectors.
C-64 and A-02NG
Repair
OK
Check trouble symptom.NGCheck the harness between free wheel
engage switch and the ABS-ECU, and
repair if necessary.
OK
Check the following connector.
C-64NG
Repair
OK
Check trouble symptom.NGReplace the ABS-ECU.

ABS <4WD> ± Troubleshooting35C-8
Code No. 26 4WD position detection switchProbable cause
This code is output at the following times:
ABS-ECU determines that an open circuit exists in the 4WD detection switch system.
The free wheel engage switch is off and the 4WD detection switch is on at a vehicle
speed of 15km/h or more for 5 seconds or more.
Malfunction of wiring harness or connector

Malfunction of free wheel engage switch

Malfunction of 4WD indicator-ECU

Malfunction of 4WD position detection switch

Malfunction of ABS-ECU
No
OK
Check trouble symptom.NGCheck the harnesses between 4WD
position detection switch and the ABS-
ECU, and repair if necessary.
OKCheck the following connector.
C-64NG
Repair
OK
Check trouble symptom.NGReplace the ABS-ECU.
Ye s
Measure at ABS-ECU connec-
tor C-64.

Disconnect the connector
and measure at the harness
side.

Ignition switch ON

Transfer lever:2H

Voltage between 35 and
body earth
OK:System voltageNGCheck the following connector.
C-64NG
Repair
Does the 4WD indicator lamp operate
normally?
Trouble symptomMain causeRemedy
Even when the transfer shift lever is
in the º4Hº position, the 4WD front
wheel indicator lamp does not
illuminate.Broken harness wire between the 4WD
indicator-ECU and the free-wheel
engage switch, or broken earth wire
from the free wheel engage switchRepair the harness.
Free wheel engage switch is defective.Replace the switch.
Even when the transfer shift lever is
in the º4Hº position, the free wheel
differential indicator lamp does not
illuminate
Broken harness wire between the 4WD
indicator-ECU and the 4WD position
detection switchRepair the harness.
illuminate.Broken wire in the 4WD indicator-ECU
circuit4WD indicator-ECU inspection (Re-
fer to GROUP 22 ± 4WD indicator-
ECU.)
Free wheel differential indicator
lamp illuminates regardless of the
p
osition of the transfer shift lever
Short in the harness wire in the 4WD
position detection switch circuitRepair the harness.
position of the transfer shift lever.4WD position detection switch is
defective.Replace the switch.
Short in the ABS-ECU circuitReplace the ABS-ECU.
Short in the 4WD indicator-ECU circuit4WD indicator-ECU inspection (Re-
fer to GROUP 22 ± 4WD indicator-
ECU.)
No indicator is illuminatedPower circuit in the 4WD indicator-ECU
is defective.Repair the harness.
4WD indicator-ECU is defective.4WD indicator-ECU inspection (Re-
fer to GROUP 22 ± 4WD indicator-
ECU.)
NOTE
When checking a short in the ABS-ECU circuit, remove the ABS-ECU connector and check if the 4WD
indicator returns to normal. If it returns to normal, the ABS-ECU is defective. Furthermore, if the ABS-ECU
is normal, then the 4WD indicator-ECU will be defective.

ABS <4WD> ± Troubleshooting35C-9
Code No. 27 Rear differential lock detection switch
Probable cause
The ABS-ECU determines that an open circuit occurs in rear differential detection
switch system.
Malfunction of wiring harness or connector

Malfunction of rear differential lock-ECU

Malfunction of ABS-ECU
Does the 4WD indicator lamp (rear dif-
ferential lamp) operate normally?NoRear differential lock-ECU check.NGReplace the rear differential lock-ECU.
Ye s
Measure at the ABS-ECU connector
C-64.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Rear differential lock switch: OFF

Voltage between 46 and body earth
OK:System voltageNGCheck the following connectors.
C-88, C-86, C-02 and C-64NG
Repair
OK
Check trouble symptom.NGCheck the harness between rear differ-
ential detection switch and the ABS-
ECU, and repair if necessary.
OK
Check the following connector.
C-64NG
Repair
OK
Check trouble symptoms.NGReplace the ABS-ECU.
Code No. 27 Rear differential lock detection switch
Probable cause
For vehicles without rear differential lock, battery positive voltage is applied to the
ABS-ECU terminal No. 46.
This code is output when this line is interrupted.
Malfunction of wiring harness or connector

Malfunction of ABS-ECU
Is the fuse No. 7 normal?NoReplace the fuse after eliminating the
cause of the blowout.
Ye s
Measure at the ABS-ECU connector
C-64.

Disconnect the connector and
measure at the harness side.

Ignition switch ON

Voltage between 46 and body earth
OK:System voltageNGCheck the following connectors.
C-88, C-86, C-02 and C-64NG
Repair
OK
Check trouble symptoms.NGCheck the harness between fuse No.
7 inside the junction block and the ABS-
ECU, and repair if necessary.
OK
Check the following connector.
C-64NG
Repair
OK
Check trouble symptoms.NGReplace the ABS-ECU.

ABS <4WD> ± Troubleshooting35C-10
Code No. 32 G-sensor systemProbable cause
This code is output at the following times:
The G-sensor output is less than 0.5 V or more than 4.5 V.
An open or short circuit is present in the G-sensor system.
Malfunction of G-sensor

Malfunction of wiring harness or connector

Malfunction of ABS-ECU
G-sensor check (Refer to P. 35C-20.)NGReplace the G-sensor.
OK
Measure at ABS-ECU connector C-62.

Ignition switch ON

Voltage between 4 and 17
OK:2.4 ± 2.6 VNGCheck the following connector.
C-02NG
Repair
OK
Check trouble symptom.NGCheck the harness between the G-sen-
sor and the ABS-ECU, and repair if nec-
essary.OK
Check the following connector.
C-62NG
Repair
OK
Check trouble symptom.
NG
Replace the ABS-ECU.
ABS WARNING LAMP INSPECTION35201200086
Refer to GROUP 35B ± Troubleshooting.
INSPECTION CHART FOR TROUBLE SYMPTOMS35201140159
Refer to GROUP 35B ± Troubleshooting.