heater ISUZU TF SERIES 2004 Owner's Guide

6B-2 ENGINE COOLING
General Description
Legend
1 Water Pump
2 Thermostat
3 Radiator
4 Reserve Tank5 Coolant Distributor
6 Cylinder Block and Head
7 Throttle Body
8 Heater




The Cooling System is a pressurized type, where the water
pump, which is cambelt driven, forces the circulation of
the coolant through the cylinder block and head. The
thermostat regulates the flow of coolant between the
radiator and the bypass circuit. The heater is part of the
bypass circuit. The throttle body pre-heat is a separate
circuit which is not regulated by the thermostat. An oil
cooler may be fitted as part of this circuit.

ENGINE COOLING 6B-13

Installation
1. Install radiator assembly, taking care not to damage the
radiator core.
2. Install the radiator assembly.
3. Connect reserve tank hose.
4. Connect radiator inlet hose and outlet hose.
5. Pour engine coolant up to filler neck of radiator, and up to
MAX mark of reserve tank.
Important operation (in case of 100% engine coolan
t
change) procedure for filling with engine coolant.

Remove radiator cap.

Fill with engine coolant (EC) to the radiator filler neck.

Fill with EC to the "MAX" line on the reservoir tank.

Start the engine with the radiator cap removed and bring to
operating temperature by running engine at 2,500 - 3,000
rpm for 30 minutes.

By EC temperature gauge reading make sure that the
thermostat is open.

If air bubbles come up to the radiator filler neck, replenish
with EC. Repeat until the EC level does not drop any further.
Install the radiator cap and stop the engine.

Replenish EC to the "MAX" line on the reservoir tank and
leave as it is until the engine gets cool.


After the engine gets cool, start the engine and make sure
there is no water running noise heard from the heater core
while the engine runs at 3000 rpm.

Should water running noise be heard, repeat the same
procedure from the beginning.


Main Data and Specifications
General Specifications
Cooling system Engine Coolant forced circulation
Radiator Tube type corrugated (2 tube in row)
Heat radiation capacity 66.3 kcal/h
Heat radiation area 7.08 m2
Radiator front area 028 m2
Radiator dry (weight) 3.1 kg
Radiator cap valve opening pressure 93.3 – 122.7 kpa
Engine coolant capacity 2.0L
Engine coolant pump Centrifugal type
Thermostat Bypass type
Engine coolant total capacity 5.7lit

ENGINE DRIVEABILITY AND EMISSIONS 6E–3
Diagnostic Aids .......................................... 6E-139
Diagnostic Trouble Code (DTC) P0118
Engine Coolant Temperature Sensor High
Input ......................................................... 6E-140
DIAGNOSTIC TROUBLE CODE (DTC) P0122
THROTTLE POSITION SENSOR LOW
INPUT ......................................................... 6E-143
Circuit Description ..................................... 6E-143
Diagnostic Aids .......................................... 6E-143
Diagnostic Trouble Code (DTC) P0122 Throttle
Position Sensor Low Input ....................... 6E-144
DIAGNOSTIC TROUBLE CODE (DTC) P0123
THROTTLE POSITION SENSOR HIGH
INPUT ...................................................... 6E-147
Circuit Description ..................................... 6E-147
Diagnostic Aids .......................................... 6E-147
Diagnostic Trouble Code (DTC) P0123 Throttle
Position Sensor High Input ...................... 6E-148
DIAGNOSTIC TROUBLE CODE (DTC) P0131
O
2 SENSOR CIRCUIT LOW VOLTAGE
(BANK 1 SENSOR 1) ................................. 6E-150
Circuit Description ..................................... 6E-150
Diagnostic Aids .......................................... 6E-150
Diagnostic Trouble Code (DTC) P0131
O
2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
6E-160
DIAGNOSTIC TROUBLE CODE (DTC) P0132 O
2
SENSOR CIRCUIT HIGH VOLTAGE (BANK 1
SENSOR 1) ................................................ 6E-155
Circuit Description ..................................... 6E-155
Diagnostic Aids .......................................... 6E-155
Diagnostic Trouble Code (DTC) P0132
O
2 Sensor Circuit High Voltage
(Bank 1 Sensor 1) .................................... 6E-156
DIAGNOSTIC TROUBLE CODE (DTC) P0134
O
2 SENSOR NO ACTIVITY DEFECTED
(BANK 1 SENSOR 1) ................................. 6E-159
Circuit Description ..................................... 6E-159
Diagnostic Aids .......................................... 6E-160
Diagnostic Trouble Code (DTC) P0134
O
2 Sensor Circuit No Activity Detected
(Bank 1 Sensor 1) .................................... 6E-160
DIAGNOSTIC TROUBLE CODE (DTC) P0135
O
2 SENSOR HEATER CIRCUIT
(BANK 1 SENSOR 1) ................................. 6E-163
Circuit Description ..................................... 6E-163
Diagnostic Aids .......................................... 6E-164
Diagnostic Trouble Code (DTC) P0135
O
2 Sensor Heater Circuit (Bank 1 Sensor 1) 6E-164
DIAGNOSTIC TROUBLE CODE (DTC) P0201
INJECTOR 1 CONTROL CIRCUIT ............. 6E-167
DIAGNOSTIC TROUBLE CODE (DTC) P0202 INJECTOR 2 CONTROL CIRCUIT ............. 6E-167
DIAGNOSTIC TROUBLE CODE (DTC) P0203
INJECTOR 3 CONTROL CIRCUIT ............. 6E-167
DIAGNOSTIC TROUBLE CODE (DTC) P0204
INJECTOR 4 CONTROL CIRCUIT ............. 6E-167
Circuit Description ...................................... 6E-167
Diagnostic Aids .......................................... 6E-168
Diagnostic Trouble Code (DTC) P0201
Injector 1 Control Circuit .......................... 6E-168
Diagnostic Trouble Code (DTC) P0202
Injector 2 Control Circuit .......................... 6E-168
Diagnostic Trouble Code (DTC) P0203
Injector 3 Control Circuit .......................... 6E-168
Diagnostic Trouble Code (DTC) P0204
Injector 4 Control Circuit .......................... 6E-168
DIAGNOSTIC TROUBLE CODE (DTC) P0325
KNOCK SENSOR (KS) MODULE CIRCUIT 6E-174
Circuit Description ...................................... 6E-174
Diagnostic Aids .......................................... 6E-174
Diagnostic Trouble Code (DTC) P0325
Knock
Sensor Module Circuit ............................. 6E-174
DIAGNOSTIC TROUBLE CODE (DTC) P0327
KNOCK SENSOR (KS) CIRCUIT ............... 6E-177
Circuit Description ...................................... 6E-177
Diagnostic Aids .......................................... 6E-177
Diagnostic Trouble Code (DTC) P0327
Knock Sensor Circuit ............................... 6E-178
DIAGNOSTIC TROUBLE CODE (DTC) P0336
CRANKSHAFT POSITION (CKP) SENSOR
CIRCUIT RANGE/PERFORMANCE (58X) . 6E-180
DIAGNOSTIC TROUBLE CODE (DTC) P0337
CRANKSHAFT POSITION (CKP) SENSOR
CIRCUIT LOW INPUT (58X) ...................... 6E-180
Circuit Description ...................................... 6E-180
Diagnostic Aids .......................................... 6E-181
Diagnostic Trouble Code (DTC) P0336
Crankshaft Position Sensor Circuit
Range/performance (58x) ........................ 6E-181
Diagnostic Trouble Code (DTC) P0337
Crankshaft Position Sensor Circuit Low
Input (58x) ............................................... 6E-181
DIAGNOSTIC TROUBLE CODE (DTC) P0351
IGNITION 1 CONTROL CIRCUIT ............... 6E-186
DIAGNOSTIC TROUBLE CODE (DTC) P0352
IGNITION 2 CONTROL CIRCUIT ............... 6E-186
Circuit Description ...................................... 6E-186
Diagnostic Aids .......................................... 6E-186
Diagnostic Trouble Code (DTC) P0351
Ignition 1 Control Circuit .......................... 6E-187
Diagnostic Trouble Code (DTC) P0352
Ignition 2 Control Circuit .......................... 6E-187

ENGINE DRIVEABILITY AND EMISSIONS 6E–29
No. Connector face No. Connector face
E-84
Knock sensorP-1
Silver Battery (+)
E-85
MAP sensorP-2
Silver Relay & Fuse box
F-2
White Fuel pump & sensorP-5
Silver Battery (-)
H-4
White Engine room ~ MissionP-6
Silver Body earth (Ground)
H-6
White Engine room ~ INSTP-10
Silver Engine ground
H-7
White Engine room ~ INSTX-2
Black Relay; Fuel pump
H-9
Blue Engine room ~ ChassisX-11
Black Relay; Heater
H-18
White Engine room ~ INSTX-14
Black Relay; A/C Compressor
H-31
Engine room ~ Mission
H-34
Engine ~ Engine room

ENGINE DRIVEABILITY AND EMISSIONS 6E–31
RELAY A ND FUSE BOX LOCATION (LHD & RHD)
RELAY & FUSE BOX
RELAY
No. Relay Name
X-1 RELAY; TAIL LIGHT
X-2 RELAY; FUEL PUMP
X-3 RELAY; HORN
X-4 RELAY; DIMMER
X-5 RELAY; FRT FOG
LIGHT (LHD only)
X-6 RELAY; STARTER
X-7 RELAY; COND, FAN
X-8—
X-9—
X-10—
X-11 RELAY; HEATER
X-12 RELAY; HEAD LIGHT
X-13—
X-14 RELAY; A/C COMP
X-15 RELAY; THERMO
FUSE
NO. Fuse Name
EB-1 15A ECM
EB-2—
EB-3 15A FRT FOG
EB-4 15A ACG (S)
EB-5 10A ILLUMI
EB-6 10A TAIL
EB-7 10A H/LIGHT-RH
10A H/LIGHT-RH-LOW
EB-8 10A H/LIGHT-LH
10A H/LIGHT-LH-LOW
(LHD only)
EB-9 20A FUEL PUMP
EB-10 10A O
2 SENSOR
EB-11 10A H/LIGHT-RH-
HIGH (LHD only)
EB-12 10A H/LIGHT-LH-
HIGH (LHD only)
EB-13 10A A/C
EB-14—
EB-15 10A HORN
EB-16 10A HAZARD
SLOW BLOW FUSE
NO. Slow Blow Fuse Name FUSE NO. Slow Blow Fuse Name
SBF-1 100A MAIN SBF-6—
SBF-2—SBF-7—
SBF-3—SBF-8 30A BLOWER
SBF-4 20A COND, FAN SBF-9 50A IG 2
SBF-5 40A IG 1

ENGINE DRIVEABILITY AND EMISSIONS 6E–51
Intake Air Temperature (IAT) Sensor
The IAT sensor is a thermistor. A temperature changes
the resistance value. And it changes voltage. In other
words it measures a temperature value. Low air
temperature produces a high resistance.
The ECM supplies 5 volts signal to the IAT sensor
through resisters in the ECM and measures the voltage.
The signal voltage will be high when the air temperature
is cold, and it will be low when the air temperature is
hot.
Vehicle Speed Sensor (VSS)
The VSS is a magnet rotated by the transmission output
shaft. The VSS uses a hall element. It interacts with the
magnetic field treated by the rotating magnet. It outputs
pulse signal. The 12 volts operating supply from the
meter fuse.
Heated Oxygen (O2) Sensor
The heated ox ygen sensor consists of a 4-wire low
temperature activated zirconia ox ygen analyzer element
with heater for operating temperature of 315°C, and
there is one mounted on each ex haust pipe.
A constant 450millivolt is supplied by the ECM between
the two supply terminals, and oxygen concentration in
the ex haust gas is reported to the ECM as returned
signal voltage.
The ox ygen present in the ex haust gas reacts with the
sensor to produce a voltage output. This voltage should
constantly fluctuate from approx imately 100mV to
1000mV and the ECM calculates the pulse width
commanded for the injectors to produce the proper
combustion chamber mix ture.
Low ox ygen sensor output voltage is a lean mix ture
which will result in a rich commanded to compensate.
High ox ygen sensor output voltage is a rich mix ture
which result in a lean commanded to compensate.
When the engine is first started the system is in “Open
Loop” operation. In “Open Loop”, the ECM ignores the
signal from the ox ygen sensors. When various
conditions (ECT, time from start, engine speed &
ox ygen sensor output) are met, the system enters
“Closed Loop” operation. In “Closed Loop”, the ECM
calculates the air fuel ratio based on the signal from the
ox ygen sensors.
Heated ox ygen sensors are used to minimize the
amount of time required for closed loop fuel control to
begin operation and allow accurate catalyst monitoring.
The ox ygen sensor heater greatly decreases the
amount of time required for fuel control sensors to
become active.
Oxygen sensor heaters are required by catalyst monitor
and sensors to maintain a sufficiently high temperature
which allows accurate ex haust ox ygen content readings
further away from the engine.
C haract erist ic of I A T Sen sor -Ref erence-
10 100 1000 10000 100000
- 20 - 10 0 10 20 30 40 50 60 70 80 90 100 110 120
I nt ake A i r T emp. ( deg . C ) ( Tec h2 R eadi ng )
Resistance (ohm) (Solid Line)

6E–116 ENGINE DRIVEABILITY AND EMISSIONSP0135 A O
2 Sensor Heater Circuit (Bank 1 Sensor
1)1. No DTC relating to MAP sensor and ECT
sensor.
2. Engine coolant temperature is more than
60 deg. C.
3. Engine run time is longer than 20
seconds.
4. MAP sensor output is more than 70kPa.
5. O
2 sensor bank 1 heater current more
than 10mA.No fail-safe function. O
2 sensor bank 1 heater circuit is correct
condition.1. Heater harness open, short to ground or
short to voltage circuit.
2. O
2 sensor heater malfunction.
3. ECM malfunction.J2-31
P0201 A Injector 1 Control Circuit 1. Engine is running.
2. Engine speed is more than 1000rpm.
3. Injector voltage does not meet to the
battery voltage when the injector is
commanded Off or does not meet to the
0V when the injector is commanded On.Injector circuit is correct condition. 1. Injector harness open circuit, short to
ground or short to voltage circuit.
2. Injector malfunction.
3. ECM malfunction.J1-9
P0202 A Injector 2 Control CircuitJ1-22
P0203 A Injector 3 Control CircuitJ1-8
P0204 A Injector 4 Control CircuitJ1-11
P0325 B Knock Sensor Module Circuit 1. No DTC relating to MAP sensor.
2. Engine coolant temperature is more than
50 deg. C.
3. Engine speed is more than 1600rpm.
4. Knock sensor filter module integrated
circuit malfunction.ECM retards ignition timing 4 deg.
C.Knock sensor is correct condition. 1. KS harness open circuit.
2. Poor connector connection.
3. KS sensor malfunction.
4. ECM malfunction.J1-3/
J1-32
P0327 A Knock Sensor Circuit 1. No DTC relating to MAP sensor.
2. Engine coolant temperature is more than
50 deg. C.
3. Engine speed is more than 1600rpm.
4. Knock sensor harness short to ground or
short to voltage circuit.1. KS harness short to ground or short to
voltage circuit.
2. Poor connector connection.
3. KS sensor malfunction.
4. ECM malfunction.J1-3/
J1-32
P0336 B Crankshaft Position Sensor Circuit Range/
Performance (58X)1. Engine is running.
2. Extra or missing pulse is detected
consecutively. No fail-safe function. Correct pulse is detected consecutively. 1. CKP sensor harness open circuit, short to
ground or short to voltage circuit.
2. Poor connector connection.
3. CKP sensor malfunction.
4. Pulse sensing gap incorrect.
5. Pluser malfunction.
6. Electrical interference.
7. Magnetic interference.
8. ECM malfunction.J1-6/
J1-21
P0337 B Crankshaft Position Sensor Circuit Low
Input (58X)No pulse is detected during engine cranking.1. CKP sensor harness open circuit, short to
ground or short to voltage.
2. Poor connector connection.
3. CKP sensor malfunction.
4. Pulse sensing gap incorrect.
5. Pluser malfunction.
6. Electrical interference.
7. Magnetic interference.
8. ECM malfunction.J1-6/
J1-21 Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up) Recovery Condition Related Failure Parts Related
ECM
Pin No.

6E–152 ENGINE DRIVEABILITY AND EMISSIONS
Poor ECM to engine block grounds.
Fuel pressure - The system will go lean if pressure is
too low. The ECM can compensate for some
decrease. However, if fuel pressure is too low, a
Diagnostic Trouble Code P0131 may be set. Refer to
Fuel System Diagnosis.
Lean injector(s) - Perform “I njector Balance Test.”
Vacuum leaks - Check for disconnected or damaged
vacuum hoses and for vacuum leaks at the intake
manifold, throttle body, EGR system, and PCV
system.Ex haust leaks - An ex haust leak may cause outside
air to be pulled into the ex haust gas stream past the
HO2S, causing the system to appear lean. Check for
exhaust leaks that may cause a false lean condition
to be indicated.
Fuel contamination - Water, even in small amounts,
can be delivered to the fuel injectors. The water can
cause a lean ex haust to be indicated. Ex cessive
alcohol in the fuel can also cause this condition. For
the procedure to check for fuel contamination, Refer
to Fuel System Diagnosis.
Diagnostic Trouble Code (DTC) P0131
O
2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
Step A ction Value(s) Yes No
1 Was 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 By Priority” in “F0:
Diagnostic Trouble Code”.
Is the DTC P0131 stored as “Present Failure”?—Go to Step 3Refer to
Diagnostic Aids
and Go to Step
3
3 1. Using the Tech2, ignition “On” and engine “Off”.
2. Select “Clear DTC Information” with the Tech2 and
clear the DTC information.
3. Operate the vehicle and monitor the “F5: Failed
This Ignition” in “F2: DTC Information”.
Was the DTC P0131 stored in this ignition cycle?—Go to Step 4Refer to
Diagnostic Aids
and Go to Step
4
4 Check for poor/faulty connection at the O
2 sensor or
ECM connector. If a poor/faulty connection is found,
repair as necessary.
Was the problem found?
—Verify repair Go to Step 5
5 Using the DVM and check the O
2 sensor circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the O
2 sensor connector.
3. Check the circuit for short to heater ground or
ground circuit.
Was the DVM indicated specified value?
Approximatly
450mV Go to Step 7Go to Step 6
C56(J2) E77
31 216
V
2 1
E77

ENGINE DRIVEABILITY AND EMISSIONS 6E–153
6 Using the DVM and check the O2 sensor 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 O
2 sensor.
4. Check the circuit for short to heater ground or
short to ground circuit.
Was the problem found?
Breaker box is not available:
1. Ignition “Off”, engine “Off”.
2. Disconnect the O
2 sensor connector and ECM
connector.
3. Check the circuit for short to heater ground or
short to ground circuit.
Was the problem found?
—Repair faulty
harness and
verify repair Go to Step 15
7 Using the DVM and check the O
2 sensor circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the the O
2 sensor connector.
3. Check the circuit for short to heater ground circuit.
Was the DVM indicated specified value?
No continuity Go to Step 9Go to Step 8
8 Repair the short to heater ground circuit.
Was the problem found?—Verify repair Go to Step 15 Step A ction Value(s) Yes No
J2-6J2-21 Breaker BoxJ2-31






C-56(J2)



C-56(J2)




O2 Sensor










ENGINE DRIVEABILITY AND EMISSIONS 6E–157
6 Using the DVM and check the O2 sensor circuit.
1. Ignition “On”, engine “Off”.
2. Disconnect the O
2 sensor connector.
3. Check the circuit for short to power supply circuit.
Was the DVM indicated specifed value?
Less than 1V Go to Step 15Repair faulty
harness and
verify repair
7 Using the DVM and check the O
2 sensor circuit.
1. Ignition “Off”, engine “Off”.
2. Disconnect the the O
2 sensor connector.
3. Check the circuit for short to heater power supply
circuit.
Was the DVM indicated specified value?
No continuity Go to Step 9Go to Step 8
8 Repair the short to heater power supply circuit.
Was the problem found?—Verify repair Go to Step 15
9 1. Using the Tech 2, ignition “On” and engine “On”.
2. Monitor the “Manifold Absolute Pressure” in the
data display.
Does the Tech 2 indicate correct “Manifold Absolute
Pressure” in accordance with engine speed or
acceleration? —Go to Step 11Go to Step 10
10 Remove the MAP sensor and check for the following
conditions.
Objects blocking the air cleaner.
Objects blocking the MAP sensor.
Objects blocking the throttle valve.
Vacuum leaking at intake duct.
Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found?—Verify repair Go to Step 11
11 1. Using the Tech 2, ignition “On” and engine “On”.
2. Select the “Miscellaneous Test” and perform the
“IAC Control” in the “IAC System”.
3. Operate the Tech 2 in accordance with procedure.
Was the engine speed changed, when the IAC valve
is operating step by step?—Go to Step 13Go to Step 12 Step A ction Value(S) Yes No
12
VV
E77
1 2 4
1234
O2 Sensor