2004 ISUZU TF SERIES instrument panel

8A-176 ELECTRICAL-BODY AND CHASSIS
This illustration is based on RHD model
TURN SIGNAL SWITCH
Removal
1. Disconnect the battery ground cable.
2. Remove the steering wheel
1.
Refer to the “STEERING” Section of this Manual.
3. Remove the instruments panel lower cover
2.
4. Remove the steering column cover
3.

This illustration is based on RHD model
5. Disconnect the connector.
6. Remove the turn signal switch from the steering shaft.




Installation
Follow the removal procedure in the reverse order to install the
turn signal switch (lever).
Pay close attention to the important points mentioned in the
following paragraphs.



Connector
Be absolutely sure that the turn signal switch connector is
securely connected.
This will prevent a poor contact and at an open circuit.

ELECTRICAL-BODY AND CHASSIS 8A-177

REAR COMBINATION LIGHT
Back Up Light
Removal
1. Open the rear gate.
2. Remove the screws.
3. Remove the rear combination light assembly.

4. Turn the bulb
3 counterclockwise to remove it.



Installation
Follow the removal procedure in the reverse order to install the
rear combination light.
Pay close attention to the important points mentioned in the
following paragraphs.



Bulbs
Be absolutely sure that each bulb is correctly installed.
This will prevent a poor contact and an open circuit.

This illustration is based on RHD model

HAZARD WARNING FLASHER SWITCH
Removal
1. Disconnect the battery ground cable.
2. Instrument Panel Cluster Assembly

Refer to Section 10 “BODY” for instrument panel cluste
r
assembly removal steps.
3. Hazard Warning Switch

Disconnect the switch connector.

To remove the switch, push the lock from the back side
of the cluster assembly.


Installation
To install, follow the removal procedure in the reverse order.



Connector
Be absolutely sure that the hazard warning flasher switch
connector is securely connected.
This will prevent a poor contact and an open circuit.

8A-262 ELECTRICAL-BODY AND CHASSIS
REMOVAL AND INSTALLATION

This illustration is based on RHD model
METER ASSEMBLY
Removal
1. Meter Cluster Assembly

Refer to the removal steps of “INSTRUMENT PANEL” in
Section 10 “CAB”
2. Meter Assembly

Remove three screws of the meter assembly.

Disconnect the meter connectors.






Installation
Follow the removal procedure in the reverse order to install the
meter.
Pay close attention to the important points mentioned in the
following paragraphs.



Connector
Be absolutely sure that the meter connectors are securely
connected.
This will prevent a poor contact and an open circuit.



Wire Harness
Do not pinch the wire harness between the cluster and the
meter hood during the meter assembly installation procedure.
Wire damage will result.

ELECTRICAL-BODY AND CHASSIS 8A-355
REMOVAL AND INSTALLATION

865R300008


REAR DEFOGGER SWITCH
Removal
1. Instrument Panel Cluster Assembly

Refer to Section 10 “BODY” for center cluster panel
assembly removal steps.
2. Rear Defogger Switch (With HVAC control unit)
Refer to Section 1 “HVAC” HVAC control unit assembly
removal steps.



Installation
Follow the removal procedure in the reverse order to install the
rear defogger switch.

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–83
ECM detects a DTC that will impact the vehicle
emissions.
When the check engine lamp remains “ON” while the
engine is running, or when a malfunction is
suspected due to a driveability or emissions problem,
a Powertrain On-Board Diagnostic (OBD) System
Check must be performed. The procedures for these
checks are given in On-Board Diagnostic (OBD)
System Check. These checks will ex pose faults
which may not be detected if other diagnostics are
performed first.
Data Link Connector (DLC)
The provision for communication with the contorl
module is the Data Link Connector (DLC). It is located
behind the lower front instrument panel. The DLC is
used to connect to a Tech 2. Some common uses of the
Tech 2 are listed below:
Identifying stored Diagnostic Trouble Codes (DTCs).
Clearing DTCs.
Reading serial data.
Verifying Vehicle Repair
Verification of vehicle repair will be more
comprehensive for vehicles with OBD system
diagnostic. Following a repair, the technician should
perform the following steps:
1. Review and record the Fail Records for the DTC
which has been diagnosed.
2. Clear DTC(s).
3. Operate the vehicle within conditions noted in the
Fail Records.
4. Monitor the DTC status information for the specific
DTC which has been diagnosed until the diagnostic
test associated with that DTC runs.
Following these steps is very important in verifying
repairs on OBD systems. Failure to follow these steps
could result in unnecessary repairs.
Reading Flash Diagnostic Trouble Codes
The provision for communicating with the Engine
Control Module (ECM) is the Data Link Connector
(DLC). The DLC is located in the front console box . It is
used in the assembly plant to receive information in
checking that the engine is operating properly before it
leaves the plant.
The diagnostic trouble code(s) (DTCs) stored in the
ECM’s memory can be read either through a hand-held
diagnostic scanner plugged into the DLC or by counting
the number of flashes of the check engine lamp when
the diagnostic test terminal of the DLC is grounded. The
DLC terminal “6” (diagnostic request) is pulled “Low”
(grounded) by jumping to DLC terminal “4 or 5”, which is
a ground wire.
This will signal the ECM that you want to “flash” DTC(s),
if any are present. Once terminals “4 or 5” and “6” have
been connected, the ignition switch must be moved to
the “ON” position, with the engine not running.
The check engine lamp will indicate a DTC three times if
a DTC is present. If more than one DTC has been
stored in the ECM’s memory, the DTC(s) will be output
from the lowest to the highest, with each DTC being
displayed three times.
The DTC display will continue as long as the DLC is
shorted.
Reading Diagnostic Trouble Codes Using a
Tech 2
The procedure for reading diagnostic trouble code(s) is
to used a diagnostic Tech 2. When reading DTC(s),
follow instructions supplied by Tech 2 manufacturer.
For the 1998 model year, Isuzu dealer service
departments will continue to use Tech 2.
Clearing Diagnostic Trouble Codes
To clear Diagnostic Trouble Codes (DTCs), use the
Te c h 2 “clear DTCs” or “clear information” function.
When clearing DTCs follow instructions supplied by the
Tech 2 manufacturer.
History DTC
History DTC can be candeled after 40 cycle driving with
no defect. Or history code can be deleted by Tech 2
“Clear DTCs” function.

6E–92 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
MISCELLANEOUS TEST
The state of each circuit can be tested by using
miscellaneous test menus. Especially when DTC
cannot be detected, a faulty circuit can be diagnosed by
testing each circuit by means of these menus.
Even DTC has been detected, the circuit tests using
these menus could help discriminate between a
mechanical trouble and an electrical trouble.
Connect Tech 2 and select "Powertrain", "4JA1-TC
Bosch" or "4JH1-TC Bosch" & "Miscellaneous Test".
F0: Lamps
F0: Glow Time Telltale Test
When the Tech 2 is operated, "Glow Time Indicator
Lamp" is turned on or off.
The circuit is correct if the "Glow Time Indicator Lamp"
in the instrument panel is turned on or off in accordance
with this operation.
F1: Relays
F0: Glow Time Relay Test
When the Tech 2 is operated, glow relay turns ON or
OFF.
The circuit is correct if glow relay is operated in
accordance with this operation.
F2: Solenoids
F0: EGR Solenoid Test
When the Tech 2 is operated, control duty ratio of EGR
EVRV changes to 5% to 95%.
The circuit is correct if glow relay is operated in
accordance with this operation.
Press "Active" key.
Then, EVRV duty ratio increases to 95%
Press "Inactive key".
EVRV duty ratio decreases to 5%F3: Engine Speed (RPM) Control
When the Tech 2 is operated, "Desired Idle Speed"
increases 50rpm-by-50rpm up to 1200rpm.
The circuit is correct if engine speed is changed in
accordance with this operation.
Press "Increase" key.
Then, Desired Idle speed is increases
50rpm-by-50rpm up to 1200rpm. Engine speed is
also
EGR Solenoid Test
Desired Mass Air Flow 470 mg/strk
Mass Air Flow 450 mg/strk
Engine Speed 700 rpm
Exhaust Gas Recirculation 95%
Engine Speed (RPM) Control
Engine Speed 850 rpm
Desired Idle Speed 850 rpm
Injection Quantity 7.5 mg/ strk

6E–242 4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS
4 Perform test drive and check the speed meter.
Does the speed meter indicate correct vehicle speed.—Go to Step 5Go to Step 6
5 Perform test drive and use the Tech 2.
Monitor the “Vehicle Speed” in the data display.
Does the Tech 2 indicate correct vehicle speed as
same as the speed meter indication in the instrument
panel?—Go to Step 15Go to Step 7
6 Remove the VSS from the housing case and visually
check.
Was the problem found? —Go to Step 8Go to Step 7
7 Using the DVM and check the VSS signal.
1. Ignition “On”, vehicle “Run (lift up)”.
2. Measure the VSS output voltage at sensor, TCM
(A/T 2WD), meter and ECM.
Does the tester indicate specified value?
If a oscilloscope is available, monitor the VSS signal
at each connector connection. Does the oscilloscope
indicate correct wave form?
Refer to
Diagnostic Aids
and Go to Step
15Refer the table
8 Replace the VSS.
Is the action complete?—Verify repair
9 Replace the TCM.
Is the action complete?
IMPORTANT: The replacement TCM must be
programmed. “SPS (Service Programming System)
is necessary.” —Verify repair— Step Action Value(s) Yes No
Me asure ment Position Vo lta ge (V)
(AC Range)If No
Go od
VSS terminal 3 & GND Approximately 6.0
V at 20km/hGo to
Step 8
TCM C94 conne ctor 10 &
GND (A/T 2WD)Go to
Step 9
Meter B24 connector 9 &
GNDGo to
St e p 1 0
Meter B24 connector 10 &
GNDGo to
St e p 1 2
ECM C56 connector 68 &
GNDGo to
St e p 1 3
Ve hicle Spee d Sensor (VSS) Refe re nce Wav e Fo rm
0V
Mea sure me nt Terminal: 68(+) GND(-)
Mea sure me nt Scale: 5V/div 50ms/div
Measurement Condition: Approximately 20km/h

4JA1/4JH1 ENGINE DRIVEABILITY AND EMISSIONS 6E–245
Diagnostic Trouble Code (DTC) P0500 (Symptom Code A) (Flash Code 24)
Vehicle Speed Sensor Input Signal Frequency Too High
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2Go to On Board
Diagnostic
(OBD) System
Check
2 1. Connect the Tech 2.
2. Review and record the failure information.
3. Select “F0: Read DTC Infor As Stored By ECU” in
“F0: Diagnostic Trouble Codes”.
Is the DTC P0500 (Symptom Code A) stored as
“Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech 2, ignition “On” and engine “Off”.
2. Select “F1: Clear DTC Information” in “F0:
Diagnostic Trouble Codes” with the Tech 2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F0: Read
DTC Infor As Stored By ECU” in the “F0:
Diagnostic Trouble Codes”.
Was the DTC P0500 (Symptom Code A) stored in this
ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 Perform test drive and check the speed meter.
Does the speed meter indicate correct vehicle speed.—Go to Step 5Go to Step 6
5 Perform test drive and use the Tech 2.
Monitor the “Vehicle Speed” in the data display.
Does the Tech 2 indicate correct vehicle speed as
same as the speed meter indication in the instrument
panel?—Go to Step 10Go to Step 7
6 Remove the VSS from the housing case and visually
check.
Was the problem found? —Go to Step 8Go to Step 7