1997 MITSUBISHI TRITON relay

AUTOMATIC TRANSMISSION ± Troubleshooting23-4
TROUBLESHOOTING23100760152
STANDARD FLOW OF DIAGNOSIS TROUBLESHOOTING
Automatic transmission malfunctions may be caused by the following conditions.
(1) Improper maintenance and adjustment
(2) Shift control system malfunction
(3) Mechanical malfunctions
(4) Hydraulic malfunctions
(5) Poor engine performance
Troubleshooting in the event of any such malfunctions should begin by checking fluid level, ATF condition,
manual linkage adjustment, throttle control cable adjustment and other conditions whose deviation from
standards can be readily known. Then, road test shall be performed to determine whether or not the
problem has been corrected or more diagnosis is necessary. If the problem still persists after these tests
and corrections, hydraulic tests should be performed for further troubleshooting.
Road test (guess what causes malfunc-
tion.)
Check how A/T works in each drive
range to find a defective system.
A/T control component inspection
Check the throttle cable, inhibitor switch,
overdrive switch, overdrive solenoid
valve, overdrive control relay, defective
switch, engine coolant temperature
switch and vehicle speed sensor.
Torque converter stall test (Inspection
of engine performance and mechanical
function)
Check the engine performance, torque
converter operation and clutch and
brake sliding performance.
Hydraulic pressure test (Inspection of
hydraulic control mechanism)
Measure the fluid line pressure and
check for malfunctions of the oil pump
or regulator valve and for oil leaks.
Oil leak inspection
Visually check gaskets and oil seals for
leaks.
Adjustment of basic inspection items
ROAD TEST 23100780158
Prior to performing road test, be sure to make basic checks including check and adjustment of fluid
level and condition and adjustment of the throttle cable. For road test, the transfer must be placed in
the 2H (2WD-high) position. In road test, various changes such as slips in transmission and shifting
conditions are checked and the transmission operation at each shift position must have been checked.

AUTOMATIC TRANSMISSION ± Troubleshooting23-5
D RANGE TEST
Correct
Carry out the TEST 1 again.
Ye s
Check the shifting points.Incorrect
Line pressure malfunction

Governor malfunction

Incorrect throttle cable adjustment
Ye s
Does the upshift from 3-speed to 4-speed occur? (with throttle
valve opening under 85%)No
3 ± 4 shift valve malfunction

Governor malfunction

Overdrive switch or overdrive solenoid malfunction

Overdrive control relay malfunction

Engine coolant temperature switch malfunction <4G6>
Ye s
Does the upshift from 2-speed to 3-speed occur?No
2 ± 3 shift valve malfunction

Governor malfunction
NG
Does the upshift from 1-speed to 2-speed occur?No
1 ± 2 shift valve malfunction

Governor malfunction
TEST 1
Start with throttle valve opened (50 % and full), and check upshift
from 1-speed  2-speed, 2-speed 3-speed and 3-speed 
4-speed. Check that shifting points match shift pattern.OKTEST 2
Correct
Carry out TEST 2 again.
Ye s
Check the shifting point.Incorrect
Line pressure malfunction

Governor malfunction

Detent regulator valve malfunction
NG
Does the downshift occur?No
Shift valves malfunction

Governor malfunction

Overdrive switch or overdrive solenoid malfunction

Overdrive control relay malfunction

Detection switch malfunction
TEST 2
Kickdown traveling at 2-speed, 3-speed and 4-speed. Check that
possible kickdown vehicle speed limit at 2-speed  1-speed,
3-speed  1-speed, 3-speed  2-speed, or 4-speed  1-speed,
4-speed  2-speed, 4-speed  3-speed conforms with the shift
pattern.OKTEST 3
Correct
Carry out TEST 3 again.
Ye s
Check the Shifting point.Incorrect
Incorrect throttle cable adjustment

Governor malfunction

Line pressure malfunction

Low coast modulator valve malfunction
NG
Does the downshift from 2-speed to 1-speed occur?No
1 ± 2 shift valve malfunction

Governor malfunction
TEST 3
When traveling in 3-speed or 4-speed, release accelerator pedal
and shift to L. Check that 3-speed  2-speed or 4-speed  3-speed
takes place immediately and 2-speed  1-speed downshift con-
forms with shift pattern.OKTEST 4

AUTOMATIC TRANSMISSION ± Troubleshooting23-6
Ye s
Carry out TEST 4 again.
Ye s
Does the engine brake function in L range?NoBrake No. 3 malfunction
No
Does the engine brake function in 2 range?NoBrake No. 1 malfunction
TEST 4
When traveling in 3-speed or 4-speed, shift to 2 and L. Does the
engine brake function in each range?Ye sTEST 5
Ye s

High line pressure

Accumulator malfunction

Check ball malfunctionCarry out TEST 5 again.
TEST 5
Is there abnormal noise(s) during acceleration and deceleration?
Is there shocks when slipping and changing speed?NoTEST 6
Ye s

Incorrect torque converter installation

Oil pump malfunction

Shifting gear not meshing correctly

Incorrect drive plate installationCarry out TEST 6 again.
TEST 6
Is there abnormal noise(s) or vibration when traveling in 3-speed
or 4-speed?NoTEST 7
NOTE
Abnormal noises and vibrations are often caused by an unbalanced propeller shaft, differential, tyre,
torque converter, engine, etc. Extremely thorough inspection is therefore required.
Ye s
Carry out TEST 7 again.
Ye s
Does lock up go on, off?No
Lock up signal valve malfunction

Lock up relay valve malfunction

Lock up clutch malfunction
No
Does the moment when lock up turns ON or OFF conform with
the shift pattern?No
Governor malfunction

Line pressure malfunction
TEST 7
Check that lock up ON, OFF. Does the shifting points conform
with shift pattern?Ye sCarry out the road test in 2 range.
NOTE
(1) Determine the moment when lock up turns ON by decreased engine r/min or by a slight shock back
and forth.
(2) Determine the moment when lock up turns OFF by increased engine r/min.
(3) Check lock up condition by pumping the accelerator slightly. If engine r/min rises in accordance with
throttle valve opening size, determine that the lock up is OFF, if not, determine it ON.
(When lock up is OFF, drive power is transferred through the fluid in the torque converter and therefore,
when the accelerator pedal is depressed, slipping occurs inside the torque converter with a resulting
large increase in engine r/min.)

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-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-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.

ABS <2WD> ± Troubleshooting35B-12
Code No. 53 Motor relay, motorProbable cause
These codes are output at the following times:
When the motor relay is on but no signal is input to the motor monitor line (motor
is not operating, etc.)
When the motor relay is off but a signal is input to the motor monitor line for 5 seconds
or more (motor continues operating, etc.)
When the motor relay does not operate
Malfunction of motor relay

Malfunction of wiring harness or connector

Malfunction of hydraulic unit

Malfunction of ABS-ECU
Caution
Because force-driving of the motor by means of the actuator test will drain the battery, the engine
should be started and left to run for a while after testing is completed.
NG
Repair
MUT-II Actuator test
Is the sound of the motor operating
heard for items 01 ± 03 only?Ye sCheck the harness between the hydrau-
lic unit and ABS-ECU, and repair if nec-
essary.
No
ABS motor relay check. (Refer to
P.35B-28.)NGReplace the motor relay.
OK
Measure at motor relay connector A-38.

Disconnect the connector and
measure at the harness side.

Voltage between 5 ± body earth
OK:System voltageNGCheck the harness between fusible link
No. 11 and ABS motor relay, and repair
if necessary.
OK
Measure at ABS-ECU connectors C-62
and C-64.

Disconnect the connector and
measure at the harness side.

Resistance between 26 ± 38
OK:72 ± 88 WNGCheck the following connector.
A-38
OK
Check trouble symptoms.NGCheck the harnesses between motor
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 49 ± body earth
OK:ContinuityNGCheck the harness between the
hydraulic unit and ABS-ECU, and repair
if necessary. Motor earth, repair if
necessary.
OK
Motor operation check. (Refer to
P.35B-27.)NGReplace the hydraulic unit.
OK
Check the following connector.
C-64NG
Repair
OK
Check trouble symptoms.NGReplace the ABS-ECU.