c24se ISUZU TF SERIES 2004 Repair Manual

ELECTRICAL-BODY AND CHASSIS 8A-433


No. Connector face No. Connector face
H-1
White
Battery (+) ~ Engine room H-10
WhiteINST ~ Front Door-RH
H-2
NOT USED H-11
NOT USED
H-3
(6VE1,
4JH1-TC)
White Battery (+) ~ Engine room H-12
BlackINST ~ Roof
H-4
(C24SE)
White Engine room ~ Mission H-13
WhiteINST ~ Door -LH
H-4
(6VE1,
4JA1-TC,
4JH1-TC)
White
Engine ~ Engine room H-14
WhiteRear body ~ Rear door-LH
H-5
NOT USED H-15
White
Engine room ~ Chassis
H-6
White
Engine room ~ INST H-16
WhiteRear body ~ Rear door-RH
H-7
White
Engine room ~ INST H-17
WhiteChassis ~ License plate lamp
H-8
NOT USED H-18
White
Engine room ~ INST
H-9
Blue
Engine room ~ Chassis H-19
~
H-21 NOT USED

8A-434 ELECTRICAL-BODY AND CHASSIS


No. Connector face No. Connector face
H-22
(6VE1)
(4JH1-TC)
White Engine ~ Engine room C H-31
(C24SE)
Engine room ~ Mission
H-23
(6VE1)
(4JH1-TC)
White Engine ~ Engine room B H-32
(C24SE)
(6VE1)
Engine room ~ Rear body
H-23
(4JA1-L)
White Engine room B ~ T/misson H-33
(4JH1-TC)
Engine ~ Engine room
H-24
Black
INST ~ Front door-RH H-34
(C24SE)
Engine ~ Engine room
H-25
Black
INST ~ Front door-LH H-35

Trailer
H-26
White
INST ~ Rear body


H-27
Black
INST ~ Rear body


H-28
White
Sub harness connector


H-29
(C24SE)
Battery(+) ~ Engine room


H-30
(6VE1)
(4JH1-TC)
Engine room ~ INST

ELECTRICAL-BODY AND CHASSIS 8A-437


No. Connector face No. Connector face
P-1
Silver
Battery (+) P-9

SilverACG (B)
P-2
Silver
Relay & Fuse box P-10
SilverEngine ground
P-3

Brown
Starter (S) P-11
SilverFuse & relay box
P-4
Silver
Starter (B) P-12
NOT USED
P-4
Silver
Starter (B) P-13

Gray Shift on the fly actuator
P-5
Silver
Battery (-) P-14
WhiteFuse & relay box
P-6
Silver
Body earth (Ground) P-15
Silver2nd battery (+)
P-7
NOT USED P-16
Silver
2nd battey (-)
P-8
(C24SE)
(4JH1-TC
Green ACG (L)


P-8
(6VE1)
White ACG (L)

8A-440 ELECTRICAL-BODY AND CHASSIS


No. Connector face No. Connector face
X-1
Black
Relay ; Tail lamp X-8
(4JH1-TC)
BlackRelay ; Starter
X-2
(C24SE)
(6VE1)
Black Relay ; Front Fog lamp X-9
(6VE1)
(4JH1-TC)
BlackRelay ; Hazard-RH
X-2
(4JH1-TC)
Black Relay ; Front Fog lamp X-10
(6VE1)
(4JH1-TC)
BlackRelay ; Hazard-LH
X-3

Relay ; Horn X-11
BlackRelay ; Heater
X-4

Relay ; Dimmer X-12
BlackRelay ; Head lamp
X-5
(6VE1)
Black Relay ; Front Fog Lamp X-13
(6VE1)
(4JH1-TC)
BlackRelay ; ECM MAIN
X-5
(4JH1-TC)
Black Relay ; Spill valve X-14

BlackRelay ; A/C Compressor
X-6
(C24SE)
(6VE1)
Relay ; Starter X-15
BlackRelay ; Thermo
X-6
(4JA1-L)
Black Relay ; CSD X-16
(6VE1)
(4JH1-TC)
BlackDIODE
X-7

Relay ; Condenser Fan X-17
BlackDIODE

WORKSHOP MANUAL

TF SERIES




ENGINE
C24SE





SECTION 6

ENGINE DIAGNOSIS (C24SE) 6-1
SECTION 6
ENGINE DIAGNOSIS
CONTENTS
PAGE
Engine Diagnosis............................................................................................................... 6- 2
Hard Starting ................................................................................................................. 6- 2
Engine Compression Test Procedure ......................................................................... 6- 3
Rough Engine Idling or Engine Stalling ...................................................................... 6- 4
Rough Engine Running ................................................................................................ 6- 5
Hesitation....................................................................................................................... 6- 6
Engine Lacks Power ..................................................................................................... 6- 7
Engine Noisy ................................................................................................................. 6- 8
Abnormal Noise Due to Hydraulic Lash Adjustor ...................................................... 6- 9
Troubleshooting Procedure ......................................................................................... 6- 9
Abnormal Combustion.................................................................................................. 6-11
Engine Oil Consumption Excessive ............................................................................ 6-12
Fuel Consumption Excessive ...................................................................................... 6-13
Oil Problems .................................................................................................................. 6-13
Engine Oil Pressure Check .......................................................................................... 6-13
Malfunction Indicator Lamp ......................................................................................... 6-14

6-2 ENGINE DIAGNOSIS (C24SE)
Engine Diagnosis
Hard Starting
1.Starting Motor Does Not Turn Over
Trouble Shooting Procedure
Turn on headlights and starter switch.
Condition Possible cause Correction
Headlights go out or dim
considerably Battery run down or under
charged Recharge or replace battery
Terminals poorly connected Clean battery posts and terminals
and connect properly
Starting motor coil circuit shorted Overhaul or replace
Starting motor defective Overhaul or replace
2.Ignition Trouble - Starting Motor Turns Over But Engine Does Not Start
Spark Test
Disconnect a high tension cable from any spark plug.
Connect the spark plug tester (use commercially
available tool), crank the engine, and check if a spark is
generated in the spark plug tester. Before cranking the
engine, make sure that the spark plug tester is properly
grounded. To avoid electrical shock, do not touch the
high tension cable while the engine is running.

Condition Possible cause Correction
Spark jumps across gap Spark plug defective Clean, adjust spark gap or replace
Spark plug wire in correct Connect properly or replace
Ignition timing incorrect Refer to Ignition System
Fuel not reaching fuel injector(s)
or engine Refer to item 3 (Trouble in fuel
system)
Valve timing incorrect Adjust
Engine lacks compression Refer to item 4 (Engine lacks
compression)
No sparking takes place Ignition coil disconnected or
broken Connect properly or replace
Electronic Ignition System with
module Replace
Poor connections in engine
harness Correct
Engine Control Module cable
disconnected or defective Correct or replace

ENGINE DIAGNOSIS (C24SE) 6-3
3.Trouble in Fuel System
Condition Possible cause Correction
Starting motor turns over and
spark occurs but engine does not
start. Fuel tank empty Fill
Water in fuel system Clean
Fuel filter clogged Replace filter
Fuel pipe clogged Clean or replace
Fuel pump defective Replace
Fuel pump circuit open Correct or replace
Evaporative Emission Control
system circuit clogged Correct or replace
Multiport Fuel Injection System
faulty Refer to "Electronic Fuel Injection"
section
4.Engine Lacks Compression
Condition Possible cause Correction
Engine lacks compression Spark plug loosely fitted or spark
plug gasket defective Tighten to specified torque or
replace gasket
Spark plug wire incorrect Connect properly or replace
Valve timing incorrect Adjust
Cylinder head gasket defective Replace gasket
Valve incorrectly seated Lap valve
Valve stem seized Replace valve and valve guide
Valve spring weakened Replace
Cylinder or piston rings worn Overhaul engine
Piston ring seized Overhaul engine.

Engine Compression Test Procedure
1. Start and run the engine until the engine
reaches normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and
fuse box. 6. Engage the starter and check that the cranking
speed is approximately 300 rpm.
7. Install cylinder compression gauge into spark
plug hole.
8. With the throttle valve opened fully, keep the
starter engaged until the compression gauge
needle reaches the maximum level. Note the
reading.
9. Repeat the test with each cylinder.
The pressure difference between the individual
cylinders should not exceed 100kPa (14.5 psi).

6-4 ENGINE DIAGNOSIS (C24SE)
Rough Engine Idling or Engine Stalling
Condition Possible cause Correction
Trouble in fuel injection system Idle air control valve defective Replace
Throttle shutting off incomplete Correct or replace
Throttle position sensor circuit
open or shorted Correct or replace
Fuel injector circuits open or
shorted Correct or replace
Fuel injectors damaged Replace
Fuel pump relay defective Replace
Manifold Absolute Pressure
Sensor cable disconnected or
broken Correct or replace
Manifold Absolute Pressure
Sensor defective Replace
Engine Coolant Temperature
Sensor cable disconnected or
broken Correct or replace
Engine Coolant Temperature
Sensor defective Replace
Intake Air Temperature sensor
cable disconnected or broken Correct or replace
Intake Air Temperature sensor
defective Replace
Knock Sensor (KS) circuits open
or shorted Correct or replace
KS defective Replace
KS Module circuits open or
ground Correct or replace
KS Module defective Replace
Vehicle Speed Sensor circuit open
or shorted Correct or replace
Vehicle Speed Sensor defective Replace
Trouble in emission control
system Engine Control Module defective Replace
Canister purge solenoid circuit
open Correct
Canister purge solenoid defective Replace
Evaporative Emission Canister
Purge control valve defective Replace
Trouble in ignition system Refer to Hard Start
Troubleshooting Guide
Others Engine lacks compression Refer to Hard Start
Troubleshooting Guide
Valve incorrectly seated Lap valve
Air Cleaner Filter clogged Replace filter element
Valve timing incorrect Readjust
Idle air control valve broken Replace

ENGINE DIAGNOSIS (C24SE) 6-5
Rough Engine Running
Condition Possible cause Correction
Engine misfires regularly Ignition coil layer shorted Replace
Spark plugs fouling Clean or install hotter type plug
Spark plug(s) insulator nose
leaking Replace
Spark plug wire incorrect Connect properly or replace
Fuel injector(s) defective Replace
Engine control module faulty Replace
Engine knocks regularly Spark plugs running too hot Install colder type spark plugs
Powertrain control module faulty Replace
Engine lacks power Spark plugs fouled Clean
Spark plug wire incorrect Connect properly or replace
Fuel injectors defective Replace
Manifold Absolute Pressure
(MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defective Correct or replace
Engine Coolant Temperature
Sensor or Engine Coolant
Temperature Sensor circuit
defective Correct or replace
Engine Control Module faulty Replace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defective Correct or replace
Throttle Position Sensor or
Throttle Position Sensor circuit
defective Correct or replace
Knock Sensor or Knock Sensor
circuits defective Correct or replace
Knock Sensor Module or Knock
Sensor Module circuits defective Correct or replace