ignition MITSUBISHI TRITON 1997 Repair Manual

ABS <2WD> ± Troubleshooting35B-14
INSPECTION CHART FOR TROUBLE SYMPTOMS35201140142
Get an understanding of the trouble symptoms and check according to the inspection procedure chart.
Trouble symptomsInspection
procedure No.Reference
page
Communication with MUT-II
is notpossible
Communication with all systems is not possible.135B-15
is not ossible.
Communication with ABS only is not possible.235B-15
When the ignition key is turned to ªONº (engine stopped), the ABS warning lamp does
not illuminate.335B-16
After the engine starts, the ABS warning lamp remains illuminated.435B-16
When the ignition key is turned to ªSTARTº, the ABS warning lamp does not illuminate.535B-17
After the ignition key is turned to ªONº, the ABS warning lamp blinks twice, and when
turned to ªSTARTº, it illuminates. When returned to ªONº, the lamp flashes once, and
then switches off.635B-17
Faulty ABS operationUnequal braking power on both sides735B-18
Insufficient braking power
ABS operates under normal braking conditions
ABS operates before vehicle stops under normal
braking conditions
Large brake pedal vibration (Caution 2.)±±
Caution
1. If steering movements are made when driving at high speed, or when driving on road surfaces
with low frictional resistance, or when passing over bumps, the ABS may operate even though
sudden braking is not being applied. Because of this, when getting information from the customer,
check if the problem occurred while driving under such conditions as these.
2. During ABS operation, the brake pedal may vibrate or may not be able to be depressed. Such
phenomena are due to intermittent changes in hydraulic pressure inside the brake line to prevent
the wheels from locking and is not an abnormality.

ABS <2WD> ± Troubleshooting35B-15
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Communication with MUT-II is not possible.
(Communication with all systems is not possible.)
Probable cause
The reason is probably a defect in the power supply system (including earth) for
the diagnosis line.
Malfunction of connector

Malfunction of harness
Refer to GROUP 13A ± Troubleshooting.
Inspection Procedure 2
Communication with MUT-II is not possible.
(Communication with ABS only is not possible.)
Probable cause
When communication with the MUT-II is not possible, the cause is probably an open
circuit in the ABS-ECU power circuit or an open circuit in the diagnosis output circuit.
Blown fuse

Malfunction of wiring harness or connecter

Malfunction of ABS-ECU
OK
Check trouble symptoms.NGReplace the ABS-ECU.
OK
Check the following connectors.
C-62 and C-64NG
Repair
OK
Check trouble symptoms.NGCheck the harness wire between the
ignition switch and the ABS-ECU, and
repair if necessary.
OK
Measure at ABS-ECU connectors C-62
and C-64

Disconnect the connector and
measure at the harness side.

Continuity between 4, 15, 16, 25
(C-62), 42 (C-64) ± body earth
OK:ContinuityNG
OK
Measure at ABS-ECU connector C-62

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Voltage between 13 ± body earth
OK:System voltageNGCheck the following connectors.
C-88, C-86 and C-02NG
Repair
OK
Check trouble symptoms.NGCheck the harness between the ABS-
ECU and diagnosis connector, and re-
pair if necessary.
Measure at diagnosis connector C-35
and ABS-ECU connector C-64

Disconnect the connector and
measure at the harness side.

Continuity between the following
terminals
OK:Continuity
ABS-ECU side
Diagnosis connector sideNGCheck the following connector.
C-02NG
Repair
Repair 47
1367

ABS <2WD> ± Troubleshooting35B-16
Inspection Procedure 3
When ignition key is turned to ºONº (engine stopped),
ABS warning lamp does not illuminate.
Probable cause
When current flows in the ABS-ECU, the valve relay turns from off to on, off and
back to on again as the initial check. So the ABS warning lamp will illuminate twice
when the valve relay is off even if there is a problem with the circuit between the
ABS warning lamp and the ABS-ECU.
Therefore, if the lamp does not illuminate, the cause may be: an open circuit in the
lamp power supply circuit, a blown lamp bulb, an open circuit in both the circuit between
the ABS warning lamp and the ABS-ECU and in the circuit between the ABS warning
lamp and the valve relay.
Blown fuse

Burnt out ABS warning lamp bulb

Malfunction of wiring harness or connector
OK
Check trouble symptoms.NGReplace the combination meter. NG
Repair
OK
Check the following connectors.
C-88, C-79, C-06, C-05 and C-02
OK
Check the harnesses between the valve
relay and connector C-02 and between
the ABS-ECU and connector C-02. Re-
pair if necessary.
OK
Measure at connector C-02:

Disconnect the connector and
measure at the male pin.

Ignition switch: ON

Does the ABS warning lamp
illuminate when terminal (3) is
earthed?
OK:IlluminatesNGCheck whether the ABS warning lamp
bulb is burnt out.NGReplace the ABS warning lamp bulb.
Fuse inspection, Multi-purpose fuse No.
11NGRefer to GROUP 00 ± Inspection Ser-
vice Points for a Blown Fuse.
Inspection Procedure 4
Even after the engine is started, the ABS warning lamp
remains illuminated.
Probable cause
The cause is probably a short-circuit in the ABS warning lamp illumination circuit.
Malfunction of combination meter

Malfunction of ABS-ECU

Malfunction of wiring harness
NOTE
This trouble symptom is limited to cases where communication with the MUT-II is possible (ABS-ECU
power supply is normal) and the diagnosis code is a normal diagnosis code.
No
Check the harnesses between the combination meter and the ABS-
ECU and between the combination meter and the valve relay. Repair,
if necessary.
No

Disconnect ABS-ECU connector C-64.

Disconnect valve relay connector A-39.

Ignition switch: ON

Does the ABS warning lamp switch off?Ye sReplace the ABS-ECU.
Disconnect connector C-02 and turn the ignition switch to ON.

Does the ABS warning lamp remain illuminated?Ye sReplace the combination meter.

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-21
Connector
terminal No.SignalChecking requirementsNormal condition
43Idle-up solenoid valve (±)Ignition switch: ON (The motor is on approximately
1 second after engine is started.)2 V or less
46Ignition switchIgnition switch: ONSystem voltage
Ignition switch: START0 V
47Input from diagnosis indication
selection
Connect the MUT-II.0 V
selection
Do not connect the MUT-II.Approx. 12 V
48Input from valve relay monitorIgnition switch: ONSystem voltage
49Motor monitorIgnition switch: ON
Approximately 1 second after
Motor is on.System voltage
A roximately 1 second after
engine is startedMotor is off.0.5 V or less
50Output to ABS warning lampIgnition
switch: ON
The lamp is switched off.System voltage
switch: ON
The lamp is illuminated.0 ± 2 V
52Output to front-right hydraulic
unit solenoid valve (IN side)Ignition switch: ON (When solenoid valve is off
approximately 1 second after engine is started.)System voltage

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.

ABS <4WD> ± Troubleshooting35C-11
DATA LIST REFERENCE TABLE35201150107
The following items can be read by the MUT-II from the ABS-ECU input data.
1. When the system is normal
Item No.Check itemChecking requirementsNormal value
11Front-right wheel speed sensorPerform a test runVehicle speeds
displayed on the12Front-left wheel speed sensor
dis layed on the
speedometer
and MUTIIare13Rear-right wheel speed sensorand MUT-II are
identical.
14Rear-left wheel speed sensor
16ABS-ECU power supply
voltageIgnition switch power supply voltage and valve
monitor voltage9 ± 16 V
25Free wheel engage switchEngage 4WDON
Engage 2WDOFF
264WD detection switchPlace the transfer lever at 4H.ON
Place the transfer lever at 2H.OFF
27Rear differential lock detection
switch
Turn on the switch.ON
switch
Turn off the switch.OFF
32G-sensor output voltageStop the vehicle.2.4 ± 2.6 V
Perform a test run.Display value
fluctuates with a
mean value of
2.5 V.
33Stop lamp switchDepress the brake pedal.ON
Release the brake pedal.OFF
2. When the ABS-ECU shut off ABS operation.
When the diagnosis system stops the ABS-ECU, the MUT-II display data will be unreliable.
ACTUATOR TEST INSPECTION TABLE35201160056
Refer to GROUP 35B ± Troubleshooting.