clutch ISUZU TF SERIES 2004 Workshop Manual

6E-80 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
Parameter
Units Idle 2000rpm Definitions
23 A/C Request (Air
Conditioning) On/Off Off Off This displays the air conditioner request signal. This should display "On" when the air
conditioner switch is switched on.
24 A/C Clutch On/Off Off Off This displays whether the ECM has commanded the A/C compressor clutch "On" or
"Off".
25 EVAP Purge
Solenoid
(Evaporative
Emission) % 50
80 0 This displays the duty signal from the ECM to control the canister purge solenoid
valve.
26 Fuel Trim Cell 49
52 13
17 This displays dependent on engine speed and MAF sensor reading.
A plot of engine speed versus MAF amount is divided into the cells.
Fuel trim cell indicates which cell is currently active.
27 Fuel Pump On/Off On On This displays operating status for the fuel pump main relay.
This should display "On" when the key switch is turned on and while engine is
running.
28 Deceleration Fuel
Cutoff Active/ Inactive Inactive Inactive The ECM will command the deceleration fuel mode when it detects a closed throttle
position while the vehicle is traveling.
While in decreasing fuel mode, the ECM will decrease the amount of fuel delivered
by entering open loop and decreasing the injector pulse width.
29 Power Enrichment Yes/No No No The ECM will command power enrichment mode "Yes" when a large increase in
throttle position and load is detected.
While in power enrichment mode, the ECM will increase the amount of fuel delivered
by entering open loop and increasing the injector pulse width.
30 Vehicle Speed km/h or mph 0 0 This displays vehicle speed.
The vehicle speed is measured by ECM from the vehicle speed sensor.
31 Cam Signal Present/ Missing Present Present This displays input signal from the camshaft position sensor.
When the correct pulse is generated, signal is received.
32 PSP Switch
(Power Steering
Pressure) Normal Pressure /
High Pressure Normal PressureNormal PressureThis displays the power steering pressure signal.
This should display "High Pressure" when the steering is steered.
33 Security Code
Status Programmable/
Not
Programmable Programmable Programmable This should display "Programmable" when the correct security code & secret code
are programmed.
34 Security Code Okay/ Not Okay Okay Okay This should display "Okay" when the security code is correctly accepted.
35 Immobilizer
System Normal /
Abnormal Normal Normal This should display "Normal" when the immobilizer is correctly operated.
36 Malfunction
Indicator Lamp On/Off Off Off This displays operating status for the Check Engine Lamp.
This should display "On" when the Check Engine Lamp is turned on.
37 Time From Start   This displays the engine time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to 00:00:00

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E -83

MISCELLANEOUS TEST
The state of each circuit can be tested by using
miscellaneous test menus. Especially when DTC cannot
be detected, a faulty circuit can be diagnosed by testing
each circuit by means of these menus.
Even DTC has been detected, the circuit tests using
these menus could help discriminate between a
mechanical trouble and an electrical trouble.
Connect Tech 2 and select "Powertrain", "3.5L V6 6VE1
Hitachi" & "Miscellaneous Test".

F0: Lamps
F0: Malfunction Indicator Lamp
When the Tech 2 is operated, "Malfunction Indicato
r
Lamp (Check Engine Lamp)" is turned on or off.
The circuit is normal if the "Malfunction Indicator Lamp
(Check Engine Lamp)" in the instrument panel is turned
on or off in accordance with this operation.

F1: Relays
F0: Fuel Pump Relay
When the Tech 2 is operated, fuel pump relay signal
turns ON or OFF.
The circuit is normal if fuel pump sound is generated in
accordance with this operation when key switch is
turned ON.

"F1: A/C Clutch Relay"
When the Tech 2 is operated, A/C clutch relay signal
turns ON or OFF.
The circuit is normal if A/C compressor clutch is
energized in accordance with this operation when the
engine is running.

F2: EVAP
F0: Purge Solenoid
When the Tech 2 is operated, duty ratio of EVAP purge
solenoid is changed 10%-by-10%.

Purge Solenoid
Engine Speed 800 RPM
Desired Idle Speed 762 RPM
Engine Coolant Temperature 80

C
Start Up ECT 50

C
Intake Air Temperature 30

C
Throttle Position 0 %
EVAP Purge Solenoid 10 %



Press "Increase" key.

Then, EVAP Purge Solenoid increases

10%-by-10%.


Press "Quit" Key.

F3: IAC System
F0: RPM Control
When the Tech 2 is operated, "Desired Idle Speed"
increases 50rpm-by-50rpm up to 1550rpm.
The circuit is normal if engine speed is changed in
accordance with this operation.
RPM Control
Engine Speed 850 RPM
Desired Idle Speed 850 RPM
Engine Coolant Temperature 80

C
Start Up ECT 50

C
Intake Air Temperature 30

C
Throttle Position 0 %
Desired Idle Speed 850 RPM



Press "Increase" key.

Then, Desired Idle speed increases

50rpm-by-50rpm up to 1550rpm. Engine speed is
also changed by this operation.


Press "Quit" Key.

F0: IAC Control
When the Tech 2 is operated, "Idle Air Control"
increases or decreases 10steps-by-10steps up to
160steps.
The circuit is normal if idle engine speed is changed in
accordance with this operation.
IAC Control
Engine Speed 875 RPM
Desired Idle Speed 762 RPM
Engine Coolant Temperature 80

Start Up ECT 50

Intake Air Temperature 30

Throttle Position 0 %
Idle Air Control 30 Steps



Press "Increase" key.

Then, Idle Air Control increases 10steps-by-
10steps up to 160steps.

Engine speed is also changed by this operation.


Press "Quit" Key.

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.

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-123
A/C CLUTCH DIAGNOSIS
This chart should be used for diagnosing the electrical
portion of the A/C compressor clutch circuit. A Tech 2
will be used in diagnosing the system. The Tech 2 has
the ability to read the A/C request input to the ECM. The
Tech 2 can display when the ECM has commanded the
A/C clutch “ON." The Tech 2 should have the ability to
override the A/C request signal and energize the A/C
compressor relay.




A/C Clutch Control Circuit Diagnosis
Step Action Value (s) Yes No
1
Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (OBD)
System Check
2
Are the A/C setting conditions met?
- Go to Step 3 Set the setting
condition and Go
to Step 3
3
Is the A/C compressor worked properly?
- Diagnosis
completed Go to Step 4
4
Does the blower motor operate?
- Go to Step 6 Go to Step 5
5
Repair the blower motor circuit.
Is the action complete?
- Verify repair -
6
1. Using the Tech 2, ignition "On" and engine "On".
2. Select the "Miscellaneous Test" and perform the
"A/C Clutch Relay" in the "Relays".
3. Operate the Tech 2 in accordance with procedure.
Was the A/C compressor magnet clutch engaged,
when the Tech 2 is operated?
- Go to Step 15 Go to Step 7
7
Check the "A/C" fuse (10A). If the fuse is burnt out,
repair as necessary.
Was the problem found?
- Verify repair Go to Step 8

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-125
Step Action Value (s) Yes No
12
 Using the DVM and check the A/C compressor relay
ground circuit.
1. Ignition "Off", engine "Off".
2. Disconnect the ECM connector.
3. Remove the A/C compressor relay from the relay
box.
4. Check the circuit for open or short to ground circuit.
Was the problem found?
E-61(B)
X-14









- Repair faulty
harness and
verify repair Go to Step 13
13
Using the DVM and check the A/C magnet clutch
power supply circuit.
1. Using the Tech 2, ignition "On" and engine "Off".
2. Select the "Miscellaneous Test" and perform the
"A/C Clutch Relay" in the "Relays".
3. Operate the Tech 2 in accordance with procedure.
4. Disconnect the A/C clutch connector. Check the
circuit for open or short to ground circuit.
Was the DVM indicated specified value?
E-2
V



10 – 14.5V Go to Step 27 Go to Step 14
14
Repair the open or short to ground circuit between the
A/C compressor relay and A/C magnet clutch.
Is the action complete?
E-2X-14






- Verify repair -

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-329
SYMPTOM DIAGNOSIS
PRELIMINARY CHECKS
Before using this section, perform the "On-Board
Diagnostic (OBD) System Check" and verify all of the
following items:

The engine control module (ECM) and check engine
lamp (MIL=malfunction indicator lamp) are operating
correctly.

There are no Diagnostic Trouble Code(s) stored.

Tech 2 data is within normal operating range. Refer
to Typical Scan Data Values.

Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.

VISUAL/PHYSICAL CHECK
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time. This check should include the following items:

ECM grounds for cleanliness, tightness and proper
location.

Vacuum hoses for splits, kinks, and proper
connection. Check thoroughly for any type of leak or
restriction.

Air intake ducts for collapsed or damaged areas.

Air leaks at throttle body mounting area, manifold
absolute pressure (MAP) sensor and intake manifold
sealing surfaces.

Ignition wires for cracking, harness, and carbon
tracking.

Wiring for proper connections, pinches and cuts.

INTERMITTENT
Important: An intermittent problem may or may not turn
on the check engine lamp (MIL=malfunction indicato
r
lamp) or store a Diagnostic Trouble Code. Do NOT use
the Diagnostic Trouble Code (DTC) charts fo
r
intermittent problems.
The fault must be present to locate the problem.
Most intermittent problems are cased by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions.

Poor mating of the connector halves or a terminal
not fully seated in the connector (backed out).

Improperly formed or damaged terminal.


All connector terminals in the problem circuit should
be carefully checked for proper contact tension.

Poor terminal-to-wire connection. This requires
removing the terminal form the connector body to
check.

Ignition coils shorted to ground and arcing at ignition
wires or plugs.

Check engine lamp (MIL=malfunction indicator lamp)
wire to ECM shorted to ground.

Poor ECM grounds. Refer to the ECM wiring
diagrams.

Road test the vehicle with a Digital Multimete
r
connected to a suspected circuit. An abnormal voltage
when the malfunction occurs is a good indication tha
t
there is a fault in the circuit being monitored.
Using Tech 2 to help detect intermittent conditions. The
Tech 2 have several features that can be used to
located an intermittent condition. Use the following
features to find intermittent faults:
To check for loss of diagnostic code memory,
disconnect the mass air flow (MAF) sensor and idle the
engine until the check engine lamp (MIL=malfunction
indicator lamp) comes on. Diagnostic Trouble Code
P0102 should be stored and kept in memory when the
ignition is turned OFF.
If not, the ECM is faulty. When this test is completed,
make sure that you clear the Diagnostic Trouble Code
P0102 from memory.

An intermittent check engine lamp (MIL=malfunction
indicator lamp) with no stored Diagnostic Trouble Code
may be caused by the following:

Ignition coil shorted to ground and arcing at ignition
wires or plugs.

Check engine lamp (MIL=malfunction indicator lamp)
wire to ECM short to ground.

Poor ECM grounds. Refer to the ECM wiring
diagrams.

Check for improper installation of electrical options such
as light, cellular phones, etc. Check all wires from ECM
to the ignition control module for poor connections.
Check for an open diode across the A/C compresso
r
clutch and check for other open diodes (refer to wiring
diagrams in Electrical Diagnosis).

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-341
SURGES AND/OR CHUGS SYMPTOM
DEFINITIONS: Engine power variation under steady
throttle or cruise. Feels like the vehicle speeds up and
slows down with no charge in the accelerator pedal.




time rpm
Surge


Step Action Value (s) Yes No
1
Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (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 4 Go to Visual /
physical Check
4
Be sure that the driver understands transmission
torque converter clutch and A/C compressor operation
as explained in the owner's manual. Inform the
customer how the torque converter clutch (TCC) (if
A/T model) and the A/C clutch operate.
Is the customer experiencing a normal condition?
- System OK Go to Step 5
5
1. Using the Tech 2, ignition "On" and engine "On".
2. Monitor the "Mass Air Flow" in the data display.
Does the Tech 2 indicate correct "Mass Air Flow" as
shown in the following graph, when engine speed is
increasing little by little?




Characteris tic of MAF Sens or -Ref erence (No Engine Load)-
0 5 10 15 20 25 30 35 40 45 50
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
Eng i ne Speed ( r pm) ( T ech2 R eadi ng )
Mass Air Flow (g/s)
( T ec h2 R eadi ng)

- Go to Step 7 Go to Step 6

6E-354 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Step Action Value (s) Yes No
15
Check items that can cause the engine to run lean. Refer to
DTC P0171 "O2 Sensor System Too Lean (Bank 1)" or DTC
P0174 "O2 Sensor System Tool Lean (Bank 2)".
Was a problem found?
- Verify repair Go to Step 16
16
Check for proper ignition voltage output with the spark tester.
Was a problem found?
- Verify repair Go to Step 17
17
Check the ignition coils for cracks or carbon tracking. If a
problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 18
18
1. Remove the spark plugs and check for gas or oil fouling
cracks, wear, improper gap, burned electrodes, heavy
deposits, or improper heat range.
2. If spark plugs are fouled, the cause of fouling must be
determined before replacing the spark plugs.
Was a problem found?
- Verify repair Go to Step 19
19
Visually/physically check the vacuum hose for splits, kinks and
proper connections and routing.
Was a problem found?
- Verify repair Go to Step 20
20
Check the exhaust system for a possible restriction:

Damaged or collapsed pipes.

Internal muffler failure.
Was a problem found?
- Verify repair Go to Step 21
21
Check the torque converter clutch (TCC) for proper operation
(if A/T model). If a problem is found, repair as necessary.
Was a problem found?
- Verify repair Go to Step 22
22
Check for the following engine mechanical problems (refer to
Engine Mechanical Section):

Low compression.

Leaking cylinder head gaskets.

Worn camshaft.

Sticking or leaking valves.

Valve timing.

Broken valve springs.

Camshaft drive belt slipped or stripped.
Was a problem found?
- Verify repair Go to Step 23
23
1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no malfunctions
have been found, review/inspect the following:

Visual/physical inspection.

Tech 2 data.

All electrical connections within a suspected circuit and/or
system.
Was a problem found?
- Verify repair Go to Step 24

3.5L ENGINE DRIVEABILITY AND EMISSIONS 6E-359
POOR FUEL ECONOMY SYMPTOM
DEFINITIONS: Fuel economy, as measured by an
actual road test, is noticeably lower than expected. Also,
economy is noticeably lower than it was on this vehicle
at one time, as previousl shown by an actual road test.
(Larger than standard tires will cause odomete
r
readings to be incorrect, and that may cause fuel
economy to appear poor when it is actually normal.)



Step Action Value (s) Yes No
1
Was the "On-Board Diagnostic (OBD) System Check"
performed?
- Go to Step 2 Go to On Board
Diagnostic (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 4 Go to Visual /
physical Check.
4
Check owner's driving habits.

Is the A/C On full time (defroster mode On)?

Are tires at the correct pressure?

Are excessively heavy loads being carried?

Is acceleration too much, too often?
- Go to Step 5 Go to Step 6
5
Review the items in Step 4 with the customer and
advise as necessary.
Is the action complete?
- System OK -
6
Visually/physically check: Vacuum hoses for splits,
kinks, and improper connections.
Was a problem found?
- Verify repair Go to Step 7
7
Check for low engine coolant level.
Was a problem found?
- Verify repair Go to Step 8
8
Check for incorrect or faulty engine thermostat. Refer
to Engine Cooling.
Was a problem found?
- Verify repair Go to Step 9
9
Remove and check the air filter element for dirt or for
restrictions.
Was a problem found?
- Verify repair Go to Step 10
10
Check the torque converter clutch (TCC) for proper
operation (if A/T model). If a problem is found, repair
as necessary.
Was a problem found?
- Verify repair Go to Step 11

6-8 ENGINE DIAGNOSIS (C24SE)
Condition Possible cause Correction
Engine overheating Level of Engine Coolant too low Replenish
Thermo switch or fan motor
defective Replace
Thermostat defective Replace
Engine Coolant pump defective Correct or replace
Radiator clogged Clean or replace
Radiator filter cap defective Replace
Level of oil in engine crankcase
too low or wrong oil in engine Change or replenish
Resistance in exhaust system
increased Clean exhaust system or replace
defective parts
Throttle Position Sensor
adjustment incorrect Adjust Wide Open Throttle switch
setting
Throttle Position Sensor circuit
open or shorted Correct or replace
Cylinder head gasket damaged Replace
Cooling Fan clutch defective Replace
Fan belt slipping Adjust tension of V-belt or replace
V-belt
Engine overcooling Thermostat defective Replace (Use a thermostat set to
open at 92
C (197.6
F))
Engine lacks compression - Refer to Hard Start
Others Tire inflation pressure abnormal Adjust to recommend pressures
Brake drag Adjust
Clutch slipping Adjust or replace
Level of oil in engine crankcase
too high Correct level of engine oil

Engine Noisy
Abnormal engine noise often consists of various
noises originating in rotating parts, sliding parts and
other moving parts of the engine. It is, therefore,
advisable to locate the source of noise systematically.

Condition Possible cause Correction
Noise from crank journals or from
crank bearings
(Faulty crank journals and crank
bearings usually make dull noise
that becomes more evident when
accelerating) Oil clearance increased due to
worn crank journals or crank
bearings Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing
Crankshaft out of round Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing
Crank bearing seized Replace crank bearings and
crankshaft or regrind crankshaft
and install the over size bearing