lock ISUZU TF SERIES 2004 Workshop Manual
[x] Cancel search | Manufacturer: ISUZU, Model Year: 2004, Model line: TF SERIES, Model: ISUZU TF SERIES 2004Pages: 4264, PDF Size: 72.63 MB
Page 1985 of 4264

STARTING AND CHARGING SYSTEM (6VE1 3.5L) 6D3-13
Main Data and Specifications
General Specifications
Model ADX4IH
Rating
Voltage 12 V
Output 1.4 Kw
Time 30 sec
Number of teeth of pinion 9
Rotating direction(as viewed from pinion) Clockwise
Weight(approx.) 3.8kg (8.4lb)
No–load characteristics
Voltage /Current 11.5V/90A or less
Speed 3000rpm or more
Load characteristics
Voltage/current 8.5V/350A or less
Torque 13.2Nm (1.35kgm/9.77lb in.) or more
Speed 1000rpm or more
Locking characteristics
Voltage/current 2.4V/500A or less
Torque 11.8N
m (1.2kg
m/8.68lb in) or more
Page 1995 of 4264

STARTING AND CHARGING SYSTEM (6VE1 3.5L) 6D3-23
Main Data and Specifications
General Specifications
Parts Number 102211-1740
Model ACJV74
Rated voltage 12 V
Rated output 90 A
Rotating direction (As viewed from pulled) Clockwise
Pulley effective diameter 57.5 mm (2.26 in)
Weight 5.1 kg (11 lb)
Page 2050 of 4264

6E-54 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor, which sends a
signal necessary for deciding on injection timing to the
ECM, is mounted on the right-hand side of the cylinde
r
block.
The crankshaft has a 58 teeth press-fit timing disc, from
which the CKP sensor reads the position of the
crankshaft at all the times. It converts this to an
electrical signal, which it sends to the ECM.
Of the 58 teeth, 57 have a base with of 3°, and are
evenly spaced, but tooth No. 58 is 15° wide at its based
to serve as a timing mark, allowing the sensor to repor
t
the standard crankshaft position.
Using the 58 X signals per rotation and the timing-mark
signal sent by the CKP sensor, the ECM is able to
accurately calculate engine speed and crank position.
Also, the position of each cylinder is precisely known by
the ECM from signals sent by the camshaft position
(CMP) sensor, so the sequential multi-point fuel
injection can be controlled with accuracy.
The 58 X signals are converted by the ECM into a
retangle wave signal. This converted signal is sent from
the ECM terminal B12 to the tachometer and transfe
r
case control module (TCCM) terminal 15 (if 4WD
model).
Engine Coolant Temperature (ECT) Sensor
The ECT sensor is a thermistor. A temperature
changes the resistance value. And it changes voltage.
In other words it measures a temperature value. It is
installed on the coolant stream. Low coolan
t
temperature produces a high resistance.
The ECM supplies 5 volts signal to the ECT senso
r
through resisters in the ECM and measures the voltage.
The signal voltage will be high when the engine
temperature is cold, and it will be low when the engine
temperature is hot.
Characteris tic of ECT Sens or
10 100 1000 10000 100000-3010 50 90130Temperature (
)
Resistance (Ω)
Page 2061 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-65
3. Check Bulletins and
Troubleshooting Hints
NOTE: As estimated 30 percent of successful
vehicle repairs are diagnosed with this step!
What you should do
You should have enough information gained from
preliminary checks to accurately search for a bulletin
and other related service information. Some service
manual sections provide troubleshooting hints that
match symptoms with specific complaints.
What resources you should use
You should use the following resources for assistance
in checking for bulletins and troubleshooting hints:
Printed bulletins
Access ISUZU Bulletin Web site
Videotapes
Service manual
4. Perform Service Manual
Diagnostic Checks
What you should do
The “System Checks” in most service manual sections
and in most cells of section 8A (electrical) provide you
with:
A systematic approach to narrowing down the
possible causes of a system fault
Direction to specific diagnostic procedures in the
service manual
Assistance to identify what systems work correctly
What resources you should use
Whenever possible, you should use the following
resources to perform service manual checks:
Service manual
Technical equipment (for viewing DTCs and
analyzing data)
Digital multimeter and circuit testing tools
Other tools as needed
5a and 5b. Perform Service Manual
Diagnostic Procedures
NOTE: An estimated 40 percent of successful
vehicle repairs are diagnosed with these steps!
What you should do
When directed by service manual diagnostic checks,
you must then carefully and accurately perform the
steps of diagnostic procedures to locate the fault related
to the customer complaint.
What resources you should use
Whenever appropriate, you should use the following
resources to perform service manual diagnostic
procedures:
Service manual
Technical equipment (for analyzing diagnostic
data)
Digital multimeter and circuit testing tools
Essential and special tools
5c. Technician Self Diagnoses
When there is no DTC stored and no matching
symptom for the condition identified in the service
manual, you must begin with a thorough understanding
of how the system(s) operates. Efficient use of the
service manual combined with you experience and a
good process of elimination will result in accurate
diagnosis of the condition.
What you should do
Step 1: Identify and understand the suspect
circuit(s)
Having completed steps 1 through 4 of the Strategy
Based Diagnostics chart, you should have enough
information to identify the system(s) or sub-system(s)
involved. Using the service manual, you should
determine and investigate the following circuit
characteristics:
Electrical:
How is the circuit powered (power distribution
charts and/or fuse block details)?
How is the circuit grounded (ground distribution
charts)?
How is the circuit controlled or sensed (theory
of operation):
If it is a switched circuit, is it normally open o
r
normally closed?
Is the power switched or is the ground
switched?
Is it a variable resistance circuit (ECT senso
r
or TPS, for example)?
Is it a signal generating device (MAF senso
r
of VSS, for example)?
Page 2093 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E -97
ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK
RTW46EM F000401
CIRCUIT DESCRIPTION
The on-board diagnostic system check is the starting
point for any driveability complaint diagnosis. Before
using this procedure, perform a careful visual/physical
check of the ECM and engine grounds for cleanliness
and tightness.
The on-board diagnostic system check is an organized
approach to identifying a problem created by an
electronic engine control system malfunction.
DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection,
rubbed-through wire insulation or a wire broken inside
the insulation. Check for poor connections or a
damaged harness. Inspect the ECM harness and
connector for improper mating, broken locks, improperl
y
formed or damaged terminals, poor terminal-to-wire
connection, and damaged harness.
TEST DESCRIPTION
Number(s) below refer the step number(s) on the
Diagnostic Chart:
1. The Check Engine Lamp (MIL) should be ON
steady with the ignition "On", engine "Off". If not,
"No Check Engine Lamp (MIL)" chart should be
used to isolate the malfunction.
2. Checks the Class 2 data circuit and ensures that
the ECM is able to transmit serial data.
3. This test ensures that the ECM is capable o
f
controlling the Check Engine Lamp (MIL) and the
Check Engine Lamp (MIL) driver circuit is not
shorted to ground circuit.
4. If the engine will not start, "Engine Cranks But Will
Not Run" chart should be used to diagnose the
fault.
6. The Tech2 parameters which is not within the
typical range may help to isolate the area which is
causing the problem.
12. This vehicle is equipped with ECM which utilizes
an electrically erasable programmable read onl
y
memory (EEPROM).
Page 2097 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E -101
NO CHECK ENGINE LAMP (MIL)
RTW46EM F000401
CIRCUIT DESCRIPTION
The “Check Engine" lamp (MIL) should always be
illuminated and steady with the ignition “ON" and the
engine stopped. Ignition feed voltage is supplied to the
MIL bulb through the meter fuse. The Engine Control
Module (ECM) turns the MIL “ON" by grounding the MIL
driver circuit.
DIAGNOSTIC AIDS
An intermittent MIL may be cased by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:
Inspect the ECM harness and connections fo
r
improper mating, broken locks, improperly formed o
r
damaged terminals, poor terminal-to-wire connection,
and damaged harness.
If the engine runs OK, check for a faulty light bulb, an
open in the MIL driver circuit, or an open in the
instrument cluster ignition feed.
If the engine cranks but will not run, check for an
open ECM ignition or battery feed, or a poor ECM to
engine ground.
Page 2100 of 4264

6E-104 3.5L ENGINE DRIVEABILITY AND EMISSIONS
CHECK ENGINE LAMP (MIL) “ON" STEADY
RTW46EM F000401
CIRCUIT DESCRIPTION
The “Check Engine" lamp (MIL) should always be
illuminated and steady with ignition “ON" and the engine
stopped. Ignition feed voltage is supplied directly to the
MIL indicator. The Engine Control Module (ECM) turns
the MIL “ON" by grounding the MIL driver circuit.
The MIL should not remain “ON" with the engine
running and no DTC(s) set. A steady MIL with the
engine running and no DTC(s) suggests a short to
ground in the MIL driver circuit.
DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection,
rubbed–through wire insulation, or a wire broken inside
the insulation. Check for the following items:
Poor connection or damaged harness – Inspect the
ECM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.
Page 2107 of 4264

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-111
FUEL SYSTEM ELECTRICAL TEST
RTW36ELF000101
CIRCUIT DESCRIPTION
When the ignition switch is first turned “ON," the Engine
Control Module (ECM) energizes the fuel pump relay
which applies power to the in-tank fuel pump. The fuel
pump relay will remain “ON" as long as the engine is
running or cranking and the ECM is receiving 58X
crankshaft position pulses. If no 58X crankshaft position
pulses are present, the ECM de-energizes the fuel
pump relay within 2 seconds after the ignition is turned
“ON" or the engine is stopped.
The fuel pump delivers fuel to the fuel rail and injectors,
then to the fuel pressure regulator. The fuel pressure
regulator controls fuel pressure by allowing excess fuel
to be returned to the fuel tank. With the engine stopped
and ignition “ON," the fuel pump can be turned “ON" by
using a command by the Tech 2.
DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:
Poor connection or damaged harness –Inspect the
ECM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.
Page 2116 of 4264

6E-120 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value(s) YES NO
8 Replace the fuel pump.
Is the action complete? — Verify repair —
9
1. Disconnect the vacuum hose from the fuel
pressure regulator.
2. With the engine idling, apply 12-14 inches of
vacuum to the fuel pressure regulator.
Does the fuel pressure indicated by the fuel pressure
gauge drop by the amount specified? 21-105 kPa
(3-15 psi) Go to Step 10 Go to Step 11
10 Locate and repair the loss of vacuum to the fuel
pressure regulator.
Is the action complete? — Verify repair —
11 Replace the fuel pressure regulator.
Is the action complete? — Verify repair —
12
1. Run the fuel pump with the Tech 2.
2. After pressure has built up, turn off the pump and
clamp the supply hose shut with suitable locking
pliers.
Does the fuel pressure indicated by the fuel pressure
gauge remain constant? — Go to Step 13 Go to Step 15
13 Visually inspect the fuel supply line and repair any
leaks.
Was a problem found? — Verify repair Go to Step 14
14 Remove the fuel tank and inspect for leaky hose or
in-tank fuel line.
Was a problem found? — Verify repair Go to Step 8
15
1. If the pliers are still clamped to the fuel supply
hose, remove the locking pliers.
2. With suitable locking pliers, clamp the fuel return
line to prevent fuel from returning to the fuel tank.
3. Run the fuel pump with the Tech 2.
4. After pressure has built up, remove power to the
pump.
Does the fuel pressure indicated by the fuel pressure
gauge remain constant? — Go to Step 11 Go to Step 16
16 Locate and replace any leaking fuel injector(s).
Is the action complete? — Verify repair —
17
Is the fuel pressure indicated by the fuel pressure
gauge above the specified limit? 376 kPa (55
psi) Go to Step 18 Go to Step 21
Page 2118 of 4264

6E-122 3.5L ENGINE DRIVEABILITY AND EMISSIONS
A/C SYSTEM CIRCUIT DIAGNOSIS
RTW36EMF000101
CIRCUIT DESCRIPTION
When air conditioning and blower fan are selected, and
if the system has a sufficient refrigerant charge, a
12-volt signal is supplied to the A/C request input of the
Engine Control Module (ECM). The A/C request signal
may be temporarily canceled during system operation
by the electronic thermostat in the evaporator case. The
electronic thermostat may intermittently remove the
control circuit ground for the A/C thermostat relay to
prevent the evaporator from forming ice. When the A/C
request signal is received by the ECM, the ECM
supplies a ground from the compressor clutch relay i
f
the engine operating conditions are within acceptable
ranges. With the A/C compressor relay energized,
voltage is supplied to the compressor clutch coil.
The ECM will enable the compressor clutch to engage
whenever A/C has been selected with the engine
running, unless any of the following conditions are
present:
The A/C request switch is "Off".
The engine speed is lower than 550rpm or greate
r
than 6375rpm.
The engine coolant temperature is greater than
120.
DIAGNOSTIC AIDS
To diagnose an the intermittent fault, check for the
following conditions:
Poor connection at the ECM–Inspect connections fo
r
backed-out terminals, improper mating, broken locks,
improperly formed or damaged terminals, and poo
r
terminal-to-wire connection.
Damaged harness–Inspect the wiring harness fo
r
damage. If the harness appears to OK, observe the
A/C clutch while moving connectors and wiring
harnesses related to the A/C. A sudden clutch
malfunction will indicate the source of the intermitten
t
fault.