2004 ISUZU TF SERIES width

6E-194 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0131 A O2 Sensor Circuit Low
Voltage (Bank 1
Sensor 1) 15
P0151 A O2 Sensor Circuit Low
Voltage (Bank 2
Sensor 1) 1. No DTC relating to ECT sensor, CMP sensor, CKP sensor,
VSS, injector control circuit, ignition control circuit and O2
sensor circuit no activity (bank 1 & 2).
2. Engine speed is between 1000rpm and 4000rpm.
3. Engine coolant temperature is between 70
C and 110
C.
4. Vehicle speed is between 0km/h and 120km/h.
5. Engine load is between 80% and 160%.
6. Throttle position fluctuation is below 0.28V.
7. O2 sensor bank 1 or bank 2 output voltage is more than
400mV for 50 seconds. "Open Loop" fuel control.

CIRCUIT DESCRIPTION
The Engine Control Module (ECM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal high and signal low circuits. The
ECM constantly monitors the HO2S signal during
“closed loop" operation and compensates for a rich o
r
lean condition by decreasing or increasing injector pulse
width as necessary. If HO2S voltage remains
excessively low for an extended period of time, DTC
P0131 or P0151 will be set.
DIAGNOSTIC AIDS
Check for the following conditions:
 Heated oxygen sensor wiring – The sensor pigtail
may be routed incorrectly and contacting the exhaus
t
system.
 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 DTC
P0131 or P0151 may be set. Refer to 6E-116 Fue
l
System Diagnosis.

 Lean injector(s) – Perform “Injector Balance Test."
 Exhaust leaks – An exhaust leak may cause outside
air to be pulled into the exhaust gas stream past the
HO2S, causing the system to appear lean. Check fo
r
exhaust leaks that may cause a false lean condition
to be indicated.
 MAF sensor –The system can go lean if the MAF
sensor signal indicates an engine airflo
w
measurement that is not correct. Disconnect the MAF
sensor to see if the lean condition is corrected. If so,
replace the MAF sensor.
 Fuel contamination –Water, even in small amounts,
can be delivered to the fuel injectors. The water can
cause a lean exhaust to be indicated. Excessive
alcohol in the fuel can also cause this condition.
Refer to 6E-116 Fuel System Diagnosisfor the
procedure to check for fuel contamination.
 If none of the above conditions are present, replace
the affected HO2S.

6E-202 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Condition For Setting The DTC and Action Taken When The DTC Sets
Flash
Code Code Type DTC Name DTC Setting Condition Fail-Safe (Back Up)
P0132 A O2 Sensor Circuit High
Voltage (Bank 1
Sensor 1) 15
P0152 A O2 Sensor Circuit High
Voltage (Bank 2
Sensor 1) 1. No DTC relating to ECT sensor, CMP sensor, CKP sensor,
VSS, injector control circuit, ignition control circuit and O2
sensor circuit no activity (bank 1 & 2).
2. Engine speed is between 1000rpm and 4000rpm.
3. Engine coolant temperature is between 70
and 110
.
4. Vehicle speed is between 0km/h and 120km/h.
5. Engine load is between 80% and 160%.
6. Throttle position fluctuation is below 0.28V.
7. O2 sensor bank 1 or bank 2 output voltage is below
600mV for 50 seconds. "Open Loop" fuel control.

CIRCUIT DESCRIPTION
The Engine Control Module (ECM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal high and signal low circuits. The
ECM constantly monitors the HO2S signal during
“closed loop" operation and compensates for a rich o
r
lean condition by decreasing or increasing injector pulse
width as necessary. If the HO2S voltage remains
excessively high for an extended period of time, DTC
P0132 or P0152 will be set.
DIAGNOSTIC AIDS
Check the following items:
 Fuel pressure – The system will go rich if pressure is
too high. The ECM can compensate for some
increase. However, if fuel pressure is too high, a DTC
P0132 or P0152 may be set. Refer to 6E-116 Fue
l
System Diagnosis.
 Perform “Injector Balance Test" – Refer to 6E-116
Fuel System Diagnosis.
 Check the canister for fuel saturation – If full of fuel,
check canister control and hoses.
 MAF sensor –The system can go rich if MAF senso
r
signal indicates an engine airflow measurement that
is not correct. Disconnect the MAF sensor to see it
the rich condition is corrected. If so, replace the MAF
sensor.

 Check for a leak in the fuel pressure regulato
r
diaphragm by checking the vacuum line to the
regulator for the presence of fuel. There should be no
fuel in the vacuum line.

An intermittent throttle position sensor output will
cause the system to go rich due to a false indication
of the engine accelerating.
 Shorted Heated Oxygen Sensor (HO2S) –If the
HO2S is internally shorted, the HO2S voltage
displayed on the Tech 2 will be over 1 volt. Try
disconnecting the affected HO2S with the key “ON,"
engine “OFF." If the displayed HO2S voltage
changes from over 1000 mV to around 450 mV,
replace the HO2S. Silicon contamination of the
HO2S can also cause a high HO2S voltage to be
indicated. This condition is indicated by a powdery
white deposit on the portion of the HO2S exposed to
the exhaust stream. If contamination is noticed,
replace the affected HO2S.
 Open HO2S Signal Circuit or Faulty HO2S–
A poor
connection or open in the HO2S signal circuit can
cause the DTC to set during deceleration fuel mode.
An HO2S which is faulty and not allowing a full
voltage swing between the rich and lean thresholds
can also cause this condition. Operate the vehicle by
monitoring the HO2S voltage with a Tech 2. If the
HO2S voltage is limited within a range between 300
mV to 600 mV, check the HO2S signal circuit wiring
and associated terminal conditions.
 If none of the above conditions are present, replace
the affected HO2S.

6E-208 3.5L ENGINE DRIVEABILITY AND EMISSIONS
CIRCUIT DESCRIPTION
 The Engine Control Module (ECM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) high and low circuits. The ECM
constantly monitors the HO2S signal during “closed
loop" operation and compensates for a rich or lean
condition by decreasing or increasing injector pulse
width as necessary. If the HO2S voltage remains a
t
or near the 450 mV bias for an extended period of
time, DTC P0134 or P0154 will be set, indicating an
open sensor signal or sensor low circuit.
DIAGNOSTIC AIDS
Check for the following conditions:
 Poor connection or damaged harness – Inspect the
harness connectors for backed-out terminals,
improper mating, broken locks, improperly formed o
r
damaged terminals, poor terminal-to-wire connection,
and damaged harness.
 Faulty HO2S heater or heater circuit –With the
ignition “ON," engine “OFF," after a cool down period,
the HO2S voltage displayed on the Tech 2 is
normally 455-460 mV. A reading over 1000 m
V
indicates a signal line shorted to voltage. A reading
under 5 mV indicates a signal line shorted to ground
or signal lines shorted together.
 Intermittent test –With the Ignition “ON," monitor the
HO2S signal voltage while moving the wiring harness
and related connectors. If the fault is induced, the
HO2S signal voltage will change. This may help
isolate the location of the malfunction.


Diagnostic Trouble Code (DTC) P0134 (Flash Code 15) O2 Sensor Circuit No
Activity Detected (Bank 1 Sensor 1)
Diagnostic Trouble Code (DTC) P0154 (Flash Code 15) O2 Sensor Circuit No
Activity Detected (Bank 2 Sensor 1)
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. 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 P0134 or P0154 stored as "Present
Failure"?
- Go to Step 3 Refer 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 P0134 or P0154 stored in this ignition
cycle?
- Go to Step 4 Refer to
Diagnostic Aids
and Go to Step 4

ENGINE MECHANICAL (C24SE) 6A-39







Camshaft Housing, Check for Plane Surface
Clean
Sealing surfaces.

Inspection
Check length and width of sealing surface for deformation and
diagnosis for warpage and use straight edge feeler gauge.

Measure
Height of camshaft housing (sealing surface to sealing
surface).
Dimension I: (74.0 mm)



Cylinder Head, Removal and Installation
Important
Only remove cylinder head with engine cold (room
temperature).




Removal
1. Remove the alternator, power steering and V-belts.



Removal
2. Loosen the fastening bolts from alternator.
3. Loosen the lower alternator fastening bolt by swinging
the alternator to the rear.



Removal
4. Remove the front toothed belt cover.
5. Remove the toothed belt from camshaft pulley.
See operation "Timing Check and Adjust".

ENGINE MECHANICAL (C24SE) 6A-45



Valve Seating, Mill
Place cylinder head on block of wood.
Inlet and exhaust, Guide Drift and Valve Seat Cutter 5-8840-
2593-0.
Valve seat-45, side face, upper correction-30, side face
(arrows on cutter).
Valve seat width:

Inlet-1.0 to 1.5 mm/0.04 to 0.06 in.
Exhaust-1.7 to 2.2 mm/0.072 to 0.088 in.




Inspection
Valve stem projection-use 5-8840-2596-0.

Important!
If dimension “A” is exceeded, use new valves.
Check valve stem projection again. If dimension “A” is
exceeded, replace cylinder head.








Cylinder Head, Overhaul
Cylinder head disassembled.

Valve, Grind
Important!
Ensure that there are no crater-like burns on the valve cone.

Regrinding possible once or twice.
Grinding of valve stem end is not permitted.

Angle at valve head-44




Inspection
Check valve stem projection as shown 5-8840-2596-0.



Valve, Grind in
Lubricate valve stem, use fine-graining grinding paste.

Lift up valve from seat rythmically using valve grinding tool (1)
for distribution of grinding paste.

6A-56 ENGINE MECHANICAL (C24SE)




5. Apply a bead of sealant (TB-1207C or equivalent) in the
grooves of both bearing shells.

Important!
After installation of bearing cover, press in sealing compound
again from above, until compound emerges at the joints.


Torque - Angle Method
Bearing cover to cylinder block - 50 N
m (5.1 kgf
m) +40 to
50
Con-rod bearing cover to con-rod - 35 N

m (3.5 kgf

m) +45
to
60
.
Use new bolts.

6. Install oil pump, oil pan, bearing bridge rear crankshaft
sealing, flywheel/drive plate, and aggregates according to
the corresponding operations.









Inspection
Bearing play - bearing cover removed

Measure
With "Plastigage" (ductile plastic threads)
Cut threads to length of bearing width and lay axiaity between
crankshaft journal and bearing shell (arrowed).
Install bearing cover with correct torque.

Important!
Grease crankshaft journal and lubricate bearing shell slightly
so that the thread does not tear when the bearing cover is
moved.


Crankshaft
Inspection
End play when bearing shells are installed.
Front end contact surfaces of flywheel/flexible plate.
Permissible end play - see "Technical Data "

ENGINE MECHANICAL (C24SE) 6A-57


Inspection
Out-of-round (run-out)-middle bearing shell removed when
mounting on front and rear bearing.
Permissible out-of-round - see "Technical Data"



Bearing Free Play Measurement
Two methods for measuring bearing free play are described -
1. Plastigage method and 2. micrometer and gauge method.
The two procedures are suitable for measuring both con-rod
and main bearing free play.
For both methods ensure con-rod and main bearing caps are
identified (1) prior to removal as they are machine matched.











1.Plastigage Method
Removal
1. Remove bearing cap and shell.
2. Lightly coat journals and bearings with engine oil to
prevent Plastigage from tearing when cap is removed.

Installation
1. Lay a length of Plastigage across width of crank pin and
fit bearing cap and shell using old bolts at this stage.

Important!
Do not allow crankshaft to rotate.

Torque - Angle Method
Main bearing cap bolt - 60 N

m (6.1 kgf

m) +40
+ to 50
.
Con-rod bearing cap bolts - 35 N

m (3.6 kgf

m) +45
.




Removal
1. Remove bearing cap and shell.

Measure
Width of Plastigage -use scale supplied with Plastigage.

If con-rod bearing clearance exceeds 0.031mm/0.001in or
main journal bearing clearance exceeds 0.04mm/0.02in. -
check crankshaft journal diameters - see corresponding
operation.
Replace bearing if crankshaft is within specification - see
"Technical Data"

6A-78 ENGINE MECHANICAL (C24SE)

Adjustment Values/Checking Values

Valve clearance
Inlet Hydraulic valve lash adjustment
Outlet No adjustment necessary

Spark plugs - electrode gap 1.0  1.1mm

Compression The difference in compression
between the individual cylinders
in the engine must not exceed
100 kPa (1 bar).

Pressure loss The pressure loss of an engine
in perfect condition per cylinder
is not more than max. 25%
























Cylinder Head
Cylinder Head Gasket
Thickness - installed mm 1.2

Valve seat width at cylinder head
inlet mm 1.0 to 1.5
outlet mm 1.7 to 2.2

Valve stem play inlet mm 0.018 to 0.052
outlet mm 0.038 to 0.072

Permissible valve stem to cone runout
inlet mm 0.03
outlet mm 0.33

Overall height of cylinder head
(Sealing surface to sealing surface) mm 95.5  0.25

Installation height
inlet and
outlet valves mm 17.85 to 18.25
dimension "A" Distance Gauge
5-8840-2596-0

Installation height valve guide mm 83.50 to 83.80

Sealing surface peak-to-valley height mm max. 0.025