2004 ISUZU TF SERIES sensor

ELECTRICAL-BODY AND CHASSIS 8A-255
TROUBLESHOOTING
SPEEDOMETER
1. Speedometer and odometer do not function

Checkpoint Trouble Cause Countermeasure


Replace the vehicle speed
sensor

Vehicle speed sensor
malfunction
NG
Repair an open circuit in the
circuit or a poor connection at
the connectors
Continuity between the vehicle
speed sensor and the meter,
or the fuse RHD: C-5 (15A)
and the ground

Open circuit or poor connector
contact


Replace the case baseboard
assy

Use a meter tester to check
the speedometer function

Speedometer malfunction
NG NG OK
OK
Check the vehicle speed
sensor output
(4 pulses/1 rotation)




2. Speedometer pointer fluctuates
(May be wide fluctuation)

Replace the vehicle speed
sensor, or repair an open
circuit in the circuit or a
connectors Vehicle speed sensor
malfunction, or open circuit or
poor connector contact
NG

Replace the case baseboard
assy

Use a meter tester to check
the speedometer function

Speedometer malfunction
NG OK
Check the speed sensor
output by using the
oscilloscope

8A-256 ELECTRICAL-BODY AND CHASSIS
3. Speedometer pointer jumps erratically

Checkpoint Trouble Cause Countermeasure

Replace the vehicle speed
sensor, or repair an open
circuit in the circuit or a poor
connection at the connectors Vehicle speed sensor
malfunction, or open circuit or
poor connector contact
NG

Replace the case baseboard
assy

Use meter tester to check the
speedometer function

Speedometer malfunction
NG OK
Check the vehicle speed
sensor output by using the
oscilloscope





Inspection of a waveform by oscilloscope
1. Connect a resistance of 1.3 to 5k ohm (1.4W or more) between the harness side connectors 30 B-24 and 9

B-24 of the meter.


2. Install a speedometer tester.
2. Turn on the starter SW.
3. Check the waveform at the time when the vehicle speed is at 60km/h.





4. Trip odometer does not reset


Replace the case baseboard
assy

Faulty reset mechanism
NG Check at other kilometer
figures given by meter tester
(Reset should be made to
zero kilometer)

ELECTRICAL-BODY AND CHASSIS 8A-257
TACHOMETER
1. Tachometer does not function when engine is running

Checkpoint Trouble Cause Countermeasure

Replace the tacho sensor, or
repair open circuit or
connector contact Tacho sensor malfunction, or
open circuit or poor connector
contact
NG

Replace the case baseboard
assy

Tachometer function

Tachometer malfunction
NG OK
Pulse between connector
B-24 and the ground when
engine is running (Should be
pulse present)



2. Meter pointer fluctuates
(May be wide fluctuation)


Replace the case baseboard
assy

Tachometer malfunction
NG
Use a meter tester to check
the tachometer function

8A-264 ELECTRICAL-BODY AND CHASSIS
Installation

Rubber Seal
Be absolutely sure that the fuel tank unit rubber seal is
correctly seated.



Connector
Be absolutely sure that the fuel tank unit connector is securely
connected.
This will prevent a poor contact and an open circuit.



VEHICLE SPEED SENSOR (INSTALLED
ON THE TRANSMISSION)
Removal
1. Disconnect the connector.
2. Remove the vehicle speed sensor body by rotating it.







Installation
To Install, follow the removal steps in the reverse order, noting
the following point.
Tighten the vehicle speed sensor to the specified torque.
Vehicle Speed Sensor Tightening Torque Nm (kgfm/lb.ft)
25  4.9 (2.5  0.5/18  3.6)

8A-278 ELECTRICAL-BODY AND CHASSIS
Low Fuel Indicator Light Inspection
1. Disconnect the fuel tank unit wire connector.
2. Turn the key switch on. Check that the bulb lights.
If operation is not correct, remove and check the bulb or circuit.
or If check whether low fuel turns on fuel input (B-24) at the
time of open and key on.
 meter is check at low fuel
140R300006





Check level sensor operation
1. Remove the fuel tank unit.
2.
Apply battery voltage between terminal (B) and (C) through
a 1.12 watt bulb. Check that the bulb lights.
Note:
It will take a short time for the bulb light.
3. Submerge the sensor in fuel. Check that the bulb goes out.
If operation is not correct, replace the fuel tank unit.

BRAKE SYSTEM WARNING LIGHT
The brake system warning light comes on while the parking
brake is set and the engine run position.
Note:
The parking brake indicator light circuit is designed to
prevent driving of the vehicle with the parking brake on.
It does not indicate the condition of the parking brake
system.



The parking brake switch is in parallel with the brake fluid
switch.



The brake system warning light also comes on when reservoir
brake fluid level falls below the specified limit with the parking
brake released and the engine run position.

ELECTRICAL-BODY AND CHASSIS 8A-279




VEHICLE SPEED SENSOR (INSTALLED
ON THE TRANSMISSION)
The speed sensor is installed on the rear portion of the
transmission.
The number of pulses generated is four pulses per one rotation
of the pinion shaft.


RTW38DLF000201

8A-280 ELECTRICAL-BODY AND CHASSIS


Vehicle Speed Sensor Inspection
1. Connect the vehicle speed sensor connector 1 E-44to the
battery (+) terminal and 2
E-44 to the (-) terminal.
2. Connect a resistance of 1.3K ohm to 5K ohm (1/4 W o
r
more) between connectors 1 E-44 and 3 E-44


CAUTION:
Be extremely careful not to connect the battery (+)
terminal to the connector 3
E-44.
This may damage the vehicle speed sensor.



3. Rotate the shaft of the vehicle speed sensor slowly and
measure the voltage at the both ends with a digital tester.

The voltage, with one rotation of shaft fluctuates four times in
the following range: 10 to 14V - 2V or less.

ELECTRICAL-BODY AND CHASSIS 8A-419


No. Connector face No. Connector face
B-32
NOT USED B-44

Keyless Entry (B)
B-33

Illumination control B-45
WhiteAlarmer control unit
B-34
NOT USED B-46
Gray
Rear defogger timer
B-35
Yellow
Infrator; passenger side B-47
WhiteGlove box illumination
B-36
Yellow
Infrator; Driver side B-48
BlackG/sensor
B-37
~
B-39 NOT USED B-49
White
A/T Lever
B-40
Black
Acc socket relay B-50
WhitePower/3rd start switch
B-41
Natural
Acc socket B-51
~
B-52 NOT USED
B-42
White
Acc socket B-53
WhiteJ/B I1
B-43

Keyless Entry (A) B-54
WhiteJ/B I2