Throttle Position Sensor ISUZU TF SERIES 2004 Workshop Manual

6-14 ENGINE DIAGNOSIS (C24SE)
Malfunction Indicator Lamp
The instrument panel "CHECK ENGINE" Malfunction
Indicator lamp (MIL) illuminates by self diagnostic
system when the system checks the starting of
engine, or senses malfunctions.

Condition Possible cause Correction
"CHECK ENGINE" MIL does not
illuminate at the starting of engine Bulb defective Replace
MIL circuit open Correct or replace
Command signal circuit to operate
self diagnostic system shorted Correct or replace
Engine Control Module (ECM)
cable loosely connected,
disconnected or defective Correct or replace
ECM defective Replace
“CHECK ENGINE” MIL
illuminates, and stays on Deterioration heated oxygen
sensor of internal element Replace
Heated oxygen sensor connector
terminal improper contact
(If applicable) Reconnect properly
Heated oxygen sensor lead wire
shorted (If applicable) Correct
Heated oxygen sensor circuit
open (If applicable) Correct or replace
Deterioration engine coolant
temperature sensor of internal
element Replace
Engine coolant temperature
sensor connector terminal
improper contact Reconnect properly
Engine coolant temperature
sensor lead wire shorted Correct
Engine coolant temperature
sensor circuit open Correct or replace
Throttle position sensor open or
shorted circuits Correct or replace
Deterioration of crankshaft
position sensor Replace
Crankshaft position sensor circuit
open or shorted Correct or replace
Vehicle speed sensor circuit open Correct or replace
Manifold absolute pressure sensor
circuit open or shorted Correct or replace
Intake air temperature sensor
circuit open or shorted Correct or replace
Fuel injector circuit open or shorted Correct or replace
ECM driver transistor defective Replace EPROM or ECM
Malfunctioning of ECM RAM
(Random Access Memory) or
Malfunctioning of ECM PROM
(Programmed Read Only Memory)Replace EPROM or ECM

ENGINE MECHANICAL (C24SE) 6A-3
PAGE
ENGINE EXTERNAL PARTS ............................................................................................ 6A-65
Radiator ....................................................................................................................... 6A-65
Thermostat................................................................................................................... 6A-66
Water Pump ................................................................................................................. 6A-66
Coating sealing surfaces with Silicone Grease ....................................................... 6A-67
Alternator ..................................................................................................................... 6A-67
Starter .......................................................................................................................... 6A-67
V-belt Tension of Alternator ....................................................................................... 6A-68
FUEL INJECTION SYSTEM.............................................................................................. 6A-69
Map Sensor.................................................................................................................. 6A-69
Pressure Regulator ..................................................................................................... 6A-69
ECM (Engine Control Module).................................................................................... 6A-69
ECT ............................................................................................................................... 6A-70
Idle Air Control(IAC) Valve.......................................................................................... 6A-70
Ignition Coil ................................................................................................................. 6A-70
Crank Position Sensor................................................................................................ 6A-71
FUEL INJECTOR .............................................................................................................. 6A-72
Knock Sensor .............................................................................................................. 6A-72
Oxygen Sensor ............................................................................................................ 6A-73
Throttle Valve Position Sensor .................................................................................. 6A-73
Acclelerator Pedal and Cable..................................................................................... 6A-73
Air Cleaner Filter ......................................................................................................... 6A-74
Spark Plug Thread ...................................................................................................... 6A-75
TECHNICAL DATA ........................................................................................................... 6A-76
Recommended Troque Values................................................................................... 6A-87
SPECIAL SERVICE TOOL................................................................................................ 6A-88

ENGINE MECHANICAL (C24SE) 6A-73




Oxygen Sensor (If applicable)
Removal
1. Remove wiring harness plug.
2. Remove oxygen sensor from the front exhaust pipe.


Tighten (Torque)
Oxygen sensor in exhaust pipe - 30 N

m (3.1 kgf

m)









Throttle Valve Position Sensor
Removal
1. Remove wiring harness connector.
2. Remove throttle valve position sensor.

Installation
1. Install throttle valve position sensor.
2. Install wiring harness connector.


Accelerator Pedal and Cable
Removal
1. Remove pad stopper from pedal stop bolt.





Installation
1. Install pad stopper.

Inspection
Ensure that accelerator pedal is fully in idle position and
accelerator level at engine is in closed position.

Pull outer sleeve of accelerator cable towards pedal and check
that clip on sleeve is in slot nearest to grommet.

Reposition clip if necessary, and check that full throttle and idle
positions are obtained at engine lever.

ENGINE COOLING 6B-5
Diagnosis
Engine Cooling Trouble
Condition Possible cause Correction
Engine overheating Low Engine Coolant level Replenish
Thermo mater unit faulty Replace
Faulty thermostat Replace
Faulty Engine Coolant temperature
sensor Repair or replace
Clogged radiator Clean or replace
Faulty radiator cap Replace
Low engine oil level or use of
improper engine oil Replenish or change oil
Clogged exhaust system Clean exhaust system or replace
faulty parts
Faulty Throttle Position sensor Replace throttle valve assembly
Open or shorted Throttle Position
sensor circuit Repair or replace
Damaged cylinder head gasket Replace
Loosen V-belt tension Adjust belt tension or replace.
Collapsed hoses Replace
Faulty Fan clutch Replace
Engine overcooling Faulty thermostat Replace
Engine slow to warm-up Faulty thermostat Replace
Thermo unit faulty Replace

ENGINE DRIVEABILITY AND EMISSIONS 6E–1
ENGINE
CONTENTS
C24SE ENGINE DRIVEABILITY AND EMISSIONS
ABBREVIATIONS CHARTS ......................... 6E-6
ECM Circuit Diagram (1/2) ............................ 6E-11
ECM Circuit Diagram (2/2) ............................ 6E-12
GROUND POINT CHART - LHD G.EXP (1/4) 6E-13
GROUND POINT CHART - RHD G.EXP (1/4) 6E-17
LOCATION ................................................... 6E-21
CABLE HARNESS & CONNECTOR
LOCATION .............................................. 6E-23
CABLE HARNESS & CONNECTOR
LOCATION
LHD ................................... 6E-24
CABLE HARNESS & CONNECTOR
LOCATION
RHD ................................... 6E-25
CONNECTOR LIST ...................................... 6E-28
RELAY AND FUSE ....................................... 6E-30
RELAY AND FUSE BOX LOCATION
(LHD & RHD) ........................................... 6E-30
FUSE AND RELAY LOCATION (LHD & RHD) 6E-32
ECM WIRING DIAGRAM (1/9) ..................... 6E-33
ECM WIRING DIAGRAM (2/9) ..................... 6E-34
ECM WIRING DIAGRAM (3/9) ..................... 6E-35
ECM WIRING DIAGRAM (4/9) ..................... 6E-36
ECM WIRING DIAGRAM (5/9) ..................... 6E-37
ECM WIRING DIAGRAM (6/9) ..................... 6E-38
ECM WIRING DIAGRAM (7/9) ..................... 6E-39
ECM WIRING DIAGRAM (8/9) ..................... 6E-40
ECM WIRING DIAGRAM (9/9) ..................... 6E-41
ECM CONNECTOR PIN ASSIGNMENT &
OUTPUT SIGNAL .................................... 6E-42
GENERAL DESCRIPTION FOR ECM AND
SENSORS ............................................... 6E-48
Engine Control Module (ECM) ................... 6E-48
Manifold Absolute Pressure (MAP) Sensor 6E-48
Throttle Position Sensor (TPS) .................. 6E-49
Idle Air Control (IAC) Valve ....................... 6E-49
Crankshaft Position (CKP) Sensor ............ 6E-50
Knock Sensor (KS) .................................... 6E-50
Engine Coolant Temperature (ECT) Sensor 6E-50
Intake Air Temperature (IAT) Sensor ........ 6E-51
Vehicle Speed Sensor (VSS) .................... 6E-51
Heated Ox ygen (O
2) Sensor ..................... 6E-51
GENERAL DESCRIPTION FOR FUEL
METERING .............................................. 6E-52Battery Voltage Correction Mode ............... 6E-52
Clear Flood Mode ...................................... 6E-52
Deceleration Fuel Cutoff (DFCO) Mode .... 6E-52
Engine Speed/ Vehicle Speed/ Fuel Disable
Mode ........................................................ 6E-52
Acceleration Mode ..................................... 6E-52
Fuel Cutoff Mode ....................................... 6E-52
Starting Mode ............................................ 6E-52
Run Mode .................................................. 6E-52
Fuel Metering System Components .......... 6E-53
Fuel Injector ............................................... 6E-53
Fuel Pressure Regulator ............................ 6E-53
Fuel Rail ..................................................... 6E-53
Fuel Pump Electrical Circuit ....................... 6E-53
Thottle Body Unit ....................................... 6E-53
GENERAL DESCRIPTION FOR ELECTRIC
IGNITION SYSTEM ................................. 6E-54
Spark Plug ................................................. 6E-54
GENERAL DESCRIPTION FOR EVAPORATIVE
EMISSION SYSTEM ............................... 6E-57
EVAP Emission Control System Purpose .. 6E-57
EVAP Emission Control System Operation 6E-57
System Fault Detection .............................. 6E-57
POSITIVE CRANKCASE VENTILATION (PCV)
SYSTEM .................................................. 6E-59
Crankcase Ventilation System Purpose .... 6E-59
A/C CLUTCH DIAGNOSIS ........................ 6E-60
A/C Clutch Circuit Operation ...................... 6E-60
A/C Clutch Circuit Purpose ........................ 6E-60
A/C Request Signal ................................... 6E-60
ISUZU STRATEGY BASED DIAGNOSTICS 6E-61
Overview .................................................... 6E-61
STRATEGY BASED DIAGNOSTICS CHART 6E-61
Diagnostic Thought Process ...................... 6E-62
1. Verify the Complaint .............................. 6E-62
2. Perform Preliminary Checks .................. 6E-62
3. Check Bulletins and Troubleshooting Hints 6E-63
4. Perform Service Manual Diagnostic Checks 6E-63
5a and 5b. Perform Service Manual Diagnostic
Procedures .............................................. 6E-63
5c. Technician Self Diagnoses .................. 6E-63
5d. Intermittent Diagnosis .......................... 6E-64

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–5
ENGINE CRANKS BUT WILL NOT RUN ..... 6E-233
HARD START SYMPTOM ............................ 6E-236
ROUGH, UNSTABLE, OR INCORRECT IDLE,
STALLING SYMPTOM ............................... 6E-239
SURGES AND/OR CHUGS SYMPTOM ...... 6E-242
HESITATION, SAG, STUMBLE SYMPTOM 6E-245
CUTS OUT, MISSES SYMPTOM ................. 6E-248
LACK OF POWER, SLUGGISH OR SPONGY
SYMPTOM ................................................. 6E-251
DETONATION/SPARK KNOCK SYMPTOM 6E-254
POOR FUEL ECONOMY SYMPTOM .......... 6E-256
EXCESSIVE EXHAUST EMISSIONS OR
ODORS SYMPTOM ................................... 6E-258
DIESELING, RUN-ON SYMPTOM ............... 6E-261
BACKFIRE SYMPTOM ................................. 6E-262
ON-VEHICLE SERVICE PROCEDURE ....... 6E-264
ENGINE CONTROL MODULE (ECM) .......... 6E-264
CRANKSHAFT POSITION (CKP) SENSOR 6E-264
ENGINE COOLANT TEMPERATURE (ECT)
SENSOR .................................................... 6E-265
INTAKE AIR TEMPERATURE (IAT) SENSOR 6E-265
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR .................................................... 6E-266
THROTTLE POSITION SENSOR (TPS) ...... 6E-266
IDLE AIR CONTROL (IAC) VALVE .............. 6E-267
KNOCK SENSOR ......................................... 6E-268
POWER STEERING PRESSURE (PSP)
SWITCH ..................................................... 6E-268
HEATED OXYGEN SENSOR (HO2S) ......... 6E-269
EVAP CANISTER PURGE VALVE SOLENOID 6E-269
FUEL PRESSURE RELIEF .......................... 6E-270
FUEL RAIL ASSEMBLY ............................... 6E-270
FUEL INJECTOR .......................................... 6E-271
FUEL PRESSURE REGULATOR ................ 6E-273
IGNITION COIL ............................................ 6E-275
SPARK PLUGS ............................................ 6E-275
SPARK PLUG CABLES ................................ 6E-277
EMISSION CONTROL ; CO ADJUSTER (W/O
CATALYSTIC CONVERTER) .................. 6E-277
SPECIAL SERVICE TOOLS ......................... 6E-279

6E–6 ENGINE DRIVEABILITY AND EMISSIONS
ABBREVIATIONS CHARTS
A bbreviations A ppellation
A/C Air Conditioner
A/T Automatic Transmission
ACC Accessory
BLK Black
BLU Blue
BRN Brown
CEL Check Engine Lamp
CKP Crankshaft Position
DLC Data Link Connector
DTC Diagnostic Trouble Code
DVM Digital Volt Meter
ECM Engine Control Module
ECT Engine Coolant Temperature
EEPROM Electrically Erasable & Programmable Read Only Memory
EVAP Evaporative Emission
EVRV Electric Vacuum Regulating Valve
EXH Exhaust
FT Fuel Temperature
GND Ground
GRY Gray
HOS2 Heated Ox ygen Sensor
IAC Idel Air Control
IAT Intake Air Temperature
IG Ignition
ITP Intake Throttle Position
KS Knock Sensor
M/T Manual Transmission
MAP Manifold Absolute Pressure
MIL Malfunction Indicator Lamp
OBD On-Board Diagnostic
ORN Orange
OT Oil Temperature
PNK Pink
RED Red
SW Switch
TB Throttle Body
TEMP Temperature
TP Throttle Posi tion
VCC Voltage Constant Control
VSS Vehicle Speed Sensor
WHT Whi te
Y EL Yellow

ENGINE DRIVEABILITY AND EMISSIONS 6E–7
COMPONENT LOCATORt
1
2 4
3
(1)
(2)Air Cleaner
Idle Air Control (IAC) Valve (3)
(4)Engine Coolant Temperature (ECT) Sensor
Engine Control Module (ECM)
3 2 1
(1)
(2)
(3)Intake Air Temperature (IAT) Sensor
Idle Air Control (IAC) Valve
Throttle Position Sensor (TPS)

ENGINE DRIVEABILITY AND EMISSIONS 6E–9
(1) Crankshaft Position (CKP) Sensor(1) Knock Sensor (KS)
(1)
(2)Engine Coolant Temperature (ECT) Sensor
Thermo Meter Sensor
21
(1) Manifold Absolute Pressure (MAP) Sensor
(1)
(2)Throttle Position Sensor
Idle Air Control (IAC) Valve
2
1
(1) EVAP Purge Solenoid