2004 ISUZU TF SERIES fuse

1-96 HEATER AND AIR CONDITIONING




Open circuit between the engine
harness connector terminal No.1 (E-
13) and engine room harness
connector terminal No.2 (X-14).
YES


Is there battery voltage between the engine room
harness connector terminal No.1 (X-14) and
ground?
YES


Disconnect the A/C thermo relay.
YES

Is there continuity between the ECM harness
connector terminal No. 11 (E-61) and engine
room harness connector terminal No.4 (X-14)?
NO
Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No.1 (X-14).
NO
Open circuit between the No.EB-13
fuse and engine room harness
connector terminal No. 3 (X-14).
NO

Is there battery voltage the engine room harness
connector terminal No.3 (X-14) and ground?
YES


Is there continuity between the ECM harness
connector terminal No.31 (E-61) and engine
room harness connector terminal No.1 (X-15)? Open circuit between the ECM
harness connector No. 11 (E-61) and
engine room harness connector
terminal No. 4 (X-14).
NO
YES

Is there battery voltage between the engine room
harness connector terminal No.3 (X-15) and
ground?
Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 2 (X-15).
NO
YES

Is there continuity between the engine room harness
connector terminal No. 4 (X-15) and the engine room
harness connector terminal No. 1 (C-24)?
Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 3 (X-15).
NO


Disconnect the ECM harness connector.

Disconnect the pressure switch.

HEATER AND AIR CONDITIONING 1-97



YES

Disconnect the condenser fan relay connector
condenser fan.
YES


Is there battery voltage between the engine
room harness connector terminal NO. 3 (C-
24) and ground? Open circuit between the condenser
fan relay No.4 (X-6) 4JAH No. 3 (X-
13) and engine room harness
connector terminal No. 4 (X-14).
NO

Is there continuity between the relay terminal
No. 4 (X-6) and engine room harness connector
terminal No.4 (C-24)?
YES

connect the A/C thermo relay connector.
Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 4 (C-24).
NO
YES

Is there battery voltage between the engine
room harness connector terminal No.3 (C-55)
dd?
Open circuit between the engine room
harness connector terminal No. 2 (C-
24) and the engine room harness
connector terminal No. 2 (C-55).
NO
YES

Is there continuity between the engine room
harness connector terminal No.1 (C-55) and
ground (C-109) ? Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 3 (C-55).
NO


Disconnect the electronic themostat.


Is there continuity between the engine room
harness connector terminal No. 2 (C-55) and the
engine room harness connector terminal No. 2
(C-24)?
Open circuit between the engine
room harness connector terminal
No. 4 (X-15) and the engine room
harness connector terminal No. 1(C-
24).
NO

1-98 HEATER AND AIR CONDITIONING



YES

Disconnect the A/C switch.

Is there battery voltage between the chassis side
harness connector terminal No. 6 (B-57) and ground (C-
109)?
Open circuit between the chassis side
harness connector No. 1 (B-79) and
chassis side harness connector terminal
No. 10 (B-57).
NO
YES


Is the electronic themostat OK? Open circuit between the No. EB-13 fuse
and the chassis side harness connector
No. 6 (B-57).
NO
YES


Defective ECM Replace electronic thermostat
NO

1-100 HEATER AND AIR CONDITIONING



Replace
YES


Are the A/C thermo (X-15), heater & A/C (X-11)
and A/C compressor (X-14) relay OK?


Are the No. SBF 8 fuse (30A) and the No. EB-13
(10A) fuses OK?
YES


Is the pressure switch (C-24) OK?
YES


Are the A/C switch (B-57) and the fan switch (B-13)
OK?
NO
YES


Is there continuity between the engine harness
connector terminal No.1 (E-2) and engine room
harness connector terminal No.2 (X-14)?

Disconnect the A/C compressor relay.


Turn the ignition switch "ON" (Engine is running)


A/C switch and fan control knob (fan switch "ON")
NO
Replace
NO
Defective switch or insufficient
refrigerant
NO
NO
Does the magnetic clutch
operate?
YES
Replace


Disconnect the magnetic clutch connector.

Is there battery voltage between the engine room
harness connector terminal No.1 (E-2) and ground?
Defective compressor
YESNO
Defective magnetic clutch

HEATER AND AIR CONDITIONING 1-101



Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No.1 (X-14).
NO
YES


Is there battery voltage between the engine room
harness connector terminal No.1 (X-14) and
ground?
YES


Disconnect the A/C thermo relay.
YES


Is there continuity between the ECM harness
connector terminal No. 14 (C-56) and engine
room harness connector terminal No.4 (X-14)?
Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 3 (X-14).
NO


Is there battery voltage the engine room harness
connector terminal No.3 (X-14) and ground?
YES


Is there continuity between the ECM harness
connector terminal No. 26 (C-56) and engine
room harness connector terminal No. 1 (X-15)?Open circuit between the ECM
harness connector No.14 (C-56) and
engine room harness connector
terminal No. 4 (X-14).
NO
YES

Is there battery voltage between the engine room
harness connector terminal No. 2 (X-15) and
ground?
Open circuit between the ECM
harness connector No. 26 (C-56) and
the engine room harness connector
terminal No. 1 (X-15).
NO
YES


Is there continuity between the engine room
harness connector terminal No. 3 (X-15) and the
engine room harness connector terminal No. 1 (C-
24
).
Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 4 (X-15).
NO


Disconnect the ECM harness connector.

Disconnect the pressure switch?
Open circuit between the engine harness
connector terminal No.1 (E-3) and engine
room harness connector terminal No.2 (X-
14).
NO

1-102 HEATER AND AIR CONDITIONING



YES


Disconnect the condenser fan relay connector condenser
fan.
YES

Is there battery voltage between the engine room
harness connector terminal NO. 3 (C-24) and ground?Open circuit between the condenser fan
relay No.3 (X-7) and engine room harness
connector terminal No. 4 (X-14).
NO

Is there continuity between the relay terminal No. 3 (X-7)
and engine room harness connector terminal No.4 (C-
24)?
YES
Open circuit between the No. EB-13 fuse
and engine room harness connector
terminal No. 4 (C-24).
NO
YES


Is there continuity between the engine room harness
connector terminal No. 2 (C-55) and the engine room
harness connector terminal No. 2 (C-24)?
Open circuit between the engine room
harness connector terminal No. 4 (CX-15)
and the engine room harness connector
terminal No. 1 (C-24).
NO


Disconnect the pressure switch.


Is there continuity between the engine room harness
connector terminal No. 4 (X-15) and the engine room
harness connector terminal No. 1 (C-24).
Open circuit between the No. EB-13 fuse
and engine room harness connector
terminal No. 2 (X-15).
NO


Connect the A/C thermo relay connector.


Disconnect the electronic thermostat.

HEATER AND AIR CONDITIONING 1-103



YES


Disconnect the A/C switch.


Is there battery voltage between the chassis side
harness connector terminal No. 6 (B-57) and ground?
Open circuit between the engine room
harness connector terminal No. 2 (C-24)
and the engine room harness connector
terminal No. 2 (C-55).
NO YES


Is there battery voltage between the engine room
harness connector terminal No. 3 (C-55) and ground?
Open circuit between the No. EB-13 fuse
and engine room harness connector
terminal No. 3 (C-55).
NO YES


Is there continuity between the engine room harness
connector terminal No. 1 (C-55) and ground (C-109)?
Open circuit between the engine room
harness connector No. 1 (C-55) and ground
(C-109).
NO
YES


Is the electronic themostat OK? Open circuit between the No. EB-13 fuse
and the chassis side harness connector
No. 4 (C-55).
NO
YES


Defective ECM Replace electronic thermostat
NO

IMMOBILIZER SYSTEM 11A-31

Diagnostic procedure


Once the cause of DTC is repaired or gone,
engine can be operated normally, and present
DTC becomes history code.


History code is canceled by no repeat failure on 25
consequence ignition key on afterward.


History code cannot be canceled by batter
y
connector disconnected.
Clearing Diagnostic Trouble Codes
IMPORTANT:
Do not clear DTCs unless directed to do
so by the service information provided for each
diagnostic procedure. When DTCs are cleared, the
Failure Record data which may help diagnose an
intermittent fault will also be erased from memory.
Verifying Vehicle Repair
Verification of vehicle repair will be more
comprehensive for vehicles with immobilizer 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 DTC
which has been diagnosed until the diagnostic test
associated with that DTC runs.
Following these steps are very important in verifying
repairs on immobilizer systems. Failure to follow these
steps could result in unnecessary repairs.
Diagnostic Aids
Check the condition for system parts.



Installation condition, poor connection, damage,
system parts malfunction. Harness, Fuse, Relay,
Immobilizer coil (antenna), Key, Meter, Immobilize
r
control unit (ICU), Engine control module (ECM).
NOE: Breakage of immobilizer fuse does not operate
immobilizer system. Check engine lamp flashes at this
time.

Check the Electro-Magnetic Interference (EMI)



Location of vehicle check

Move the vehicle to a new location and perform
the check again.


Non-OEM Parts.

Switch is "OFF" or remove the Non-OEM parts and
perform the check again.


Other

Remove the accessory and another key from key.

Check the other items.



Battery voltage is low.


Immobilizer programming functions.

Must be programmed immobilizer system.


Registration for security code, immobilizer control
unit parts number.


Key switch operation.

Immobilizer system may detect a history DTC b
y
the timing of ON-OFF of a key switch.


Active the immobilizer system.


Keyless entry system is malfunction.


Anti theft system is malfunction.

Check the operation

Check the operation "Lock / unlock" by using transmitte
r
(key) on the vehicle.