fuse ISUZU TF SERIES 2004 Workshop Manual

6E–170 ENGINE DRIVEABILITY AND EMISSIONS
7 Using the DVM and check the injector power supply
circuit for the affected cylinder.
1. Ignition “On”, engine “Off”.
2. Disconnect the injector connector for the affected
cylinder.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 9Go to Step 8
8 Repair the open or short to ground circuit between the
“IGN” fuse (15A) and injector for the affected cylinder.
Is the action complete?—Veri fy repai r— Step A ction Value(s) Yes No
V
1
E-6 No.1 Cylinder
V
1
E-7 No.2 Cylinder
V
1
E-8 No.3 Cylinder
V
1
E-9 No.4 Cylinder

6E–190 ENGINE DRIVEABILITY AND EMISSIONS
8 Using the DVM and check the ignition coil module
power supply circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the ignition coil module connector.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 10Go to Step 9
9 Repair the open or short to ground circuit between the
“IGN. Coil” fuse (15A) and ignition coil module.
Is the action complete?—Veri fy repai r—
10 Replace the ignition coil module.
Was the problem solved?—Verify repair Go to Step 11
11 Is the ECM programmed with the latest software
release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved?—Verify repair Go to Step 12
12 Replace the ECM.
Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure.—Veri fy repai r— Step A ction Value(s) Yes No
V
E-18
2

ENGINE DRIVEABILITY AND EMISSIONS 6E–193
6 Using the DVM and check the purge solenoid valve
power supply circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the purge solenoid valve connector.
3. Check the circuit for open circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 8Go to Step 7
7 Repair the open or short to ground circuit between the
“Engine” fuse (15A) and purge solenoid valve.
Is the action complete?—Veri fy repai r -
8 Using the DVM and check the purge solenoid valve
solenoid signal circuit.
Breaker box is available:
1. Ignition “Off”, engine “Off”.
2. Install the breaker box as type A. (ECM
disconnected) Refer to 6E-88 page.
3. Disconnect the purge solenoid valve connector.
4. Check the circuit for open or short to ground
circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the purge solenoid valve connector
and ECM connector.
3. Check the circuit for open or short to ground
circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 9 Step A ction Value(s) Yes No
V
E-66
2
J1-5Breaker BoxE-66




E-66 E-60(J1)
51

ENGINE DRIVEABILITY AND EMISSIONS 6E–195
DIAGNOSTIC TROUBLE CODE (DTC) P0502 VEHICLE SPEED SENSOR (VSS)
CIRCUIT LOW INPUT
Condition for setting the DTC and action taken when the DTC sets
Circuit Description
The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a
hall effect circuit that interacts with the magnetic field
created by the rotating magnet. A 12-volt operating
supply for the speed sensor hall circuit is supplied from
the meter fuse.
Diagnostic Aids
Poor connection at ECM: Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.
Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0502 B Vehicle Speed Sensor Circuit Low
Input1. No DTC relating to MAP senso r, TPS, ECT
se nsor, inje ctor co ntrol circuit a nd ignitio n
co ntro l circuit.
2. Engine is running.
3. Vehicle spe ed is below 3km/h in po wer
condition or 2km/h in deceleration condi-
tion.ECM use s 0km/h co ndition a s substitute.

ENGINE DRIVEABILITY AND EMISSIONS 6E–197
6 Using the DVM and check the VSS signal.
1. Ignition “On”, vehicle “Run (lift up)”.
2. Measure the VSS output voltage at sensor, meter,
immobilizer control unit (if equipped) and ECM.
Does the tester indicate specified value?
If a oscilloscope is available, monitor the VSS signal.
Does the oscilloscope indicate correct wave form?
Refer to
Diagnostic Aids
and Go to Step
21Refer the table
7 Using the DVM and check the VSS power supply
circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the VSS connector.
3. Check the circuit for open or short to ground
circuit.
Was the DVM indicated specified value?
10 - 14.5V Go to Step 9Go to Step 8
8 Repair the open circuit between the VSS and meter
fuse.
Is the action complete?—Veri fy repai r— Step A ction Value(s) Yes No
Me asure ment Position Vo lta ge (V)
(AC Range)If No
Go od
VSS terminal 3 & GND Appro xima te ly
7.0 V at 20km/hGo to
Step 7
Meter B24 connector 9 &
GNDGo to
Step 11
Meter B24 connector 10 &
GNDGo to
St e p 1 3
Immo bilize r control unit B68
co nnecto r 6 & GNDGo to
St e p 1 4
Immo bilize r control unit B68
co nnecto r 8 & GNDApproximately
6.5V at 20km/hGo to
St e p 1 6
ECM C56 (J2) co nnecto r 23 &
GNDGo to
St e p 1 7
Vehicle Speed Sensor (V SS) Reference Wave Form








CH1
0V


CH2
0V




Measurement Terminal: CH1: ECM J2-23(+) / CH2: VSS 3(+)
GND(-)
Measurement Scale: CH1: 10V/div / CH2: 10V/div 50ms/div
Measurement Condition: A pproxim ately 20km/h
Note: The vehicle is without immobilizer syste m,
CH1 signal is sam e as CH2.
V
E-44
1

ENGINE DRIVEABILITY AND EMISSIONS 6E–233
ENGINE CRANKS BUT WILL NOT RUN
DEFINITIONS: Engine cranks, but will not run. (The engine never start.)
NOTE: The replacement ECM must be programmed. Refer to section of the Service Programming System (SPS) in
this manual. Following ECM programming, the immobilizer system (if equipped) must be linked to the ECM.
Refer to section 11 “Immobilizer System-ECM replacement” for the ECM/Immobilizer linking procedure.
NOTE: The vehicle with immobilizer system, this system may be activated. Check the immobilizer system diagosis.
Step Action Value(s) Yes No
1Was the “On-Board Diagnostic (OBD) System Check”
performed?—Go to Step 2Go to OBD
System Check
2 1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?—Verify repair Go to Step 3
3 Was a visually/physical check performed?
—Go to Step 4Go to Visual /
physical Check.
4 Check the “Ignition coil” fuse (15A) and “ECM” fuse
(15A).
Was a fuse blown?—Verify repair Go to Step 5
5 1. Ignition ON
2. Use a DVM to verify that battery voltage at the
ignition coil fuse, and the ECM fuse.
Was battery voltage presented at the fuses?—Go to Step 6Verify & repair
6 1. Visually/physically inspect for the following
conditions:
Restriction of air intake system. Check for a
restricted air filter element, or foreign objects
blocking the air intake system.
Check for objects blocking the IAC passage or
throttle bore, excessive deposits in the throttle
bore and on the throttle plate.
Check for a condition that causes a large
vacuum leak, such as an incorrectly installed or
faulty crankcase ventilation hose/brake booster
hose.
Was a problem found?—Verify repair Go to Step 7
7 1. Using a Tech 2, display the IAC value.
2. Check for a faulty, plugged, or sticking IAC
operation.
Was the problem found?—Verify repair Go to Step 8
8 1. Using a Tech 2, display the MAP sensor value.
2. Check for a faulty, plugged, or incorrectly installed
MAP sensor.
Was the problem found?—Verify repair Go to Step 9
9 If oscilloscope is available, check the wave form of the
CKP signal.
Was the correct wave form found?—Go to Step 12Go to Step 10
10 Check the CKP sensor wire for open or short circuit.
Was a problem found?—Verify repair Go to Step 11
11 Replace CKP sensor.
Is there still problem?—Replace pulsar
ring. Verify repair

1-80 HEATER AND AIR CONDITIONING

BLOWER MOTOR DOES NOT RUN


Replace
YES

Is No.SBF-8 (30A) slow blow fuse OK?

Is heater & A/C relay (X-11) OK?
YES

Is resistor OK?
YES

Is fan control knob (Fan switch) OK?
YES
YES

Check to see if battery voltage is present at
chassis side connector terminal No.C105-1 is there a
battery voltage?

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

Fan control knob (Fan switch) "ON"

Is blower motor OK?
YES
Poor ground or open circuit either between chassis
side connector terminal No.C105-2 and No.C104-3
or No.B13-1 and body ground No.C-109.
NO
Replace
NO
Replace
NO
NO
Replace control lever
assembly
Replace
NO
NO
Open circuit between
No.SBF-8 (30A) slow blow
fuse and No.C105-1.

1-90 HEATER AND AIR CONDITIONING

MAGNETIC CLUTCH DOES NOT RUN (4JA1L/4JH1-TC)



Replace
YES


Are the A/C thermo (X-15) and 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-3) 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-3) and ground?
Defective compressor
YESNO
Defective magnetic clutch

HEATER AND AIR CONDITIONING 1-91





Open circuit between the engine
harness connector terminal No.1 (E-3)
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.38 (C-56) 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 engine room
harness connector terminal No.1 (X-
15) and engine room harness
connector terminal No. 3 (X-14).
NO

Is there continuity between the engine room
harness connector terminal No.3 (X-14) and No.1
(X-15)?
YES


Is there continuity between the ECM harness
connector terminal No.30 (C-56) and engine
room harness connector terminal No.2 (X-15)? Open circuit between the engine room
harness connector terminal No.1 (X-
15) and engine room harness
connector terminal No. 3 (X-14).
NO
YES


Is there battery voltage between the engine room
harness connector terminal No.4 (X-15) and
ground?
Open circuit between the ECM
harness connector No. 38 (C-56) and
engine room harness connector
terminal No. 4 (X-14).
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?

1-92 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 4JH1TC No.4 (X-6) 4JA1L
No. 3 (X-13) and engine room harness
connector terminal No. 4 (X-14).
NO

Is there continuity between the relay terminal
4JH1TC No. 4 (X-6) 4JA1L No.3 (X-13)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. 3 (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-
55) and the engine room harness
connector terminal No. 2 (C-24).
NO
YES


Is there continuity between the engine room
harness connector terminal No.1 (C-55) and
ground (C-109) ? or (cooler only) the short
connector terminal No.3 (B-79) 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 and engine room
harness connector terminal No. 3 (X-
15) and the engine room harness
connector terminal No. 1(C-24).
NO