TROUBLESHOOTING 6 – 3
1. Hard Starting
Inspect the following items before diagnosis.
1. The battery conditions. The terminal connection condition.
The battery charge condition or battery power weakness.
2. The fan belt loosen or broken.
3. The main fuse condition (open or not).
4. Fuel quantity level.
1 –1 Starter motor inoperative
Step Action Value(s) Yes No
1 Check the starter switch. Does the starter switch work? —
Go to Step 2 Repair or
replace the
starter switch
2 Check the starter relay. Does the starter relay work? —
Go to Step 3 Repair or
replace the
starter relay
3 Check the magnetic switch. Does the magnetic switch work? —
Go to Step 4 Repair or
replace the magnetic switch
4 Check the pinion gear condition on the starter motor. Was the condition normal? —
Go to Step 5 Replace the
pinion gear
5 Check the brush wear or brush spring weakness. Was the condition normal? —
Replace the
starter motor assembly Repair or
replace the
brush or brush spring
1-2 Starter motor operates but engine does not turn over
Step Action Value(s) Yes No
1 Check the engine internal seizure. Was the engine seized? —
Repair or
replace seized parts Check other
DTC by Tech 2 and go to
indicated DTC
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ISUZU KB P190 2007
6 – 4 TROUBLESHOOTING
1-3 Engine turn over but does not start engine
Incase of the fuel not being delivered to the injection pump
Step Action Value(s) Yes No
1 Check clogged, damaged the fuel piping or the
connector loosen.
Was any problem found? —
Repair replace problem parts. Go to Step 2
2 Was the over flow valve on the fuel filter closed? — Repair replace
the over flow valve Go to Step 3
3 Was the fuel filter element clogged? — Replace the
fuel filter element Go to Step 4
4 Was the fuel line air bled? — Go to Step 5 Bleed the air
5 Are any DTC stored? — Go to indicated
DTC Solved
Incase of the fuel is being delivered to the injection pump
Step Action Value(s) Yes No
1 Was the water contain in the fuel? — Replace the
fuel Go to Step 2
2 Was the fuel line air bled? — Go to Step 5 Bleed the air
3 Was the injection spray condition complete? —
Go to Step 4 Replace the
injection nozzle
4 Was the injection nozzle injection starting pressure OK? (See below)
Go to Step 5 Replace the
injection nozzle
5 Was the injection nozzle sticking? — Replace the
injection nozzle Go to Step 6
6 Are any DTC stored? — Go to indicated
DTC Solved
Injection nozzle opening pressure
1st = 19.5 MPa (199 kg/cm2, 2828 psi)
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ISUZU KB P190 2007
TROUBLESHOOTING 6 – 5
2. Unstable Idling
Step Action Value(s) Yes No
1 Was the fuel line air bled completely? — Go to Step 3 Bleed the air
2 Was the fuel line leakage or blockage found? — Repair or
replace relation parts. Go to Step 4
3 Was the water contained in the fuel? — Replace the
fuel Go to Step 5
4 Was the fuel filter element clogged? — Replace the
fuel filter element Go to Step 6
5 Was the injection starting pressure or the injection
spray condition OK? (See below)
Go to Step 7 Replace the
injection nozzle
6 Was the injection nozzle sticking? See Step 6 Replace the
injection nozzle Go to Step 8
7 Check the throttle valve condition.
Was the idling port clogged in the throttle valve? —
Repair or
replace the
throttle valve Go to Step 9
8 Was the valve clearance improper adjusted? 0.4 mm
(0.016 in)
both intake
and exhaust valves Adjust the
valve clearance Go to Step 10
9 Was the compression pressure OK? 3,040 kPa
(31 kg/cm2,
441 psi) at 200rpm
Go to Step 11 Readjust the
valve clearance or replace the cylinder head gasket or
cylinder liner or
piston or piston ring or valve
and valve seat
10 Are any DTC stored? — Go to indicated
DTC Solved
Injection nozzle opening pressure
1st = 19.5 MPa (199 kg/cm2, 2828 psi)
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ISUZU KB P190 2007
6 – 6 TROUBLESHOOTING
3. Insufficient Power
Step Action Value(s) Yes No
1 Was the air cleaner element condition OK? (Clogged
or not) —
Go to Step 2 Clean or
replace the air cleaner
element.
2 Was the intake air leakage found from intake system? —
Repair or
replace the intake air system. Go to Step 3
3 Was the fuel filter element condition OK? (Clogged
or not) —
Go to Step 4 Clean or
replace the fuel filter element.
4 Check the fuel injection pipes. Does the injection pipes have obstruction or any
damage? —
Repair or
replace the fuel injection pipes. Go to Step 5
5 Was the water contained in the fuel? — Replace the
fuel Go to Step 6
6 Was the injection nozzle pressure or spray pattern
normal? —
Go to Step 7 Readjust the
injection nozzle pressure or replace the nozzle.
7 Was the compression pressure OK? 3.0 MPa
(31.0 kg/cm2,
441 psi) at 200 rpm
Go to Step 8 Readjust the
valve clearance or replace the cylinder head gasket or
cylinder liner or
piston or piston ring or valve
and valve seat
8 Was the exhaust pipe clogged? — Repair or
replace the
exhaust pipe. Go to Step 9
9 Was the exhaust gas leakage found from exhaust
system? —
Repair or
replace the exhaust system. Go to Step 10
10 Was the waste gate control actuator hose broken or
cracked? —
Replace the
hose. Go to Step 11
11 Was the waste gate working completely? —
Go to Step 12 Replace the
turbocharger assembly.
12 Was turbocharger working completely? —
Go to Step 13 Replace the
turbocharger assembly.
13 Are any DTC stored? — Go to indicated
DTC Solved
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ISUZU KB P190 2007
6 – 10 TROUBLESHOOTING
8. Dark Exhaust Smoke
Step Action Value(s) Yes No
1 Was the air cleaner element normal condition? —
Go to Step 2 Clean or
replace the air cleaner
element
2 Was the EGR valve sticking? — Replace the
EGR valve Go to Step 3
3 Was the injection nozzle pressure or the injection
spray pattern OK? —
Go to Step 4 Replace the
injection nozzle
4 Was the oil leakage found from the turbocharger oil seal? —
Replace the oil
seal Go to Step 5
5 Was the oil drain pipe of the turbocharger restricted? — Repair or
replace the oil drain pipe Go to Step 6
6 Was restricted the oil drain passage in the
turbocharger center housing restricted? —
Clean the
center housing Go to Step 7
7 Does turbine wheel has any impact damage? — Replace the
turbocharger Go to Step 8
8 Does PCV (Positive Crankcase Ventilation) Valve
has problem? —
Repair or
replace the
relation parts Go to Step 9
9 Are any DTC stored? — Go to indicated
DTC Solved
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ISUZU KB P190 2007
6 – 14 TROUBLESHOOTING
10-5 Excessive turbocharger noise
The vibration noise (the air aspiration noise) occurred when turbocharger rotates, it is normal condition of the
turbocharger, no necessary any actions.
Step Action Value(s) Yes No
1 Was the excessive noise coming from the turbocharger? —
Go to Step 2 Go to Step 10
2 Inspect the fixing bolts and bands.
Was any problem found? —
Tighten the
loose parts Go to Step 3
3 Was the intake or exhaust system gasket damaged? — Replace the
damaged gasket. Go to Step 4
4 Inspect rotation parts condition.
Was the turbine wheel rotation rough? —
Replace the
turbocharger. Go to Step 5
5 Inspect the turbine wheel.
Was the turbine wheel rubbing against housing? —
Replace the
turbocharger. Go to Step 6
6 Was the turbine wheel damaged? — Replace the
turbocharger. Go to Step 7
7 Were there carbon deposits in the turbine or
compressor housing? —
Clean or
replace the
turbocharger. Go to Step 8
8 Inspect the oil supply condition.
Was the oil feed pipe clogged? —
Repair or
replace the oil feed pipe. Go to Step 9
9 Was the turbine shaft bearing worn? — Replace the
turbocharger. Go to Step 10
10 Are any DTC stored? — Go to indicated
DTC Solved
11. Rotating Part Wear of Turbocharger
Step Action Value(s) Yes No
1 Inspect engine oil.
Was it contaminated with foreign materials? —
Replace the
engine oil Go to Step 2
2 Was the recommended engine oil grade/viscosity
being used? API CD or
ISUZU
genuine/ 10W –30
Go to Step 3 Replace the
engine oil
3 Was the oil feed pipe restricted? — Clean or
replace the oil feed pipe Go to Step 4
4 Was the oil seal of turbocharger defective? — Replace the oil
seal Go to Step 5
5 Was the center housing oil drain passage clogged? — Clean center
housing or
replace the
turbocharger Go to Step 6
6 Was there oil sludge and/or coking on the turbine
shaft? —
Replace the
turbocharger Go to Step 7
7 Are any DTC stored? — Go to indicated
DTC Solved
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ISUZU KB P190 2007
6 – 16 TROUBLESHOOTING
14. Battery Charging and Noise Problem
Visual/physical check the following items before diagnosis.
The drive belt tension.
The battery terminals connection condition.
The ground connection condition.
The generator and the battery fastener condition.
The battery fluid level and specific gravity.
14-1 Battery No Charging
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical check
2 Inspect the brush contact condition on the generator.
Was there poor contact between the brush and the
slip ring? —
Repair or
replace the
brush and/or the slip ring. Go to Step 3
3 Inspect the stator coil on the generator.
Was there an open circuit or the scorching on the
stator coil? —
Replace the stator coil. Go to Step 4
4 Inspect the rotor coil on the generator.
Was there an open circuit or the scorching on the
rotor coil? —
Replace the rotor coil. Go to Step 5
5 Inspect the rectifier on the generator.
Was the rectifier defective? —
Replace the
rectifier Go to Step 6
6 Inspect the IC regulator.
Was the IC regulator defective? —
Replace the IC
regulator. Go to Step 7
7 Are any DTC stored? — Go to indicated
DTC. Solved
14-2 Battery Overcharging
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical check
2 Inspect the terminal circuit.
Were the B and F terminals shorted? —
Repair the
short circuit. Go to Step 3
3 Check the regulating voltage.
Was the IC regulator voltage excessive? —
Replace the IC
regulator. Go to Step 4
4 Are any DTC stored? — Go to indicated
DTC. Solved
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ISUZU KB P190 2007
TROUBLESHOOTING 6 – 17
14-3 Battery Under Charging
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical check
2 Inspect the brush contact condition on the generator.
Was there intermittent contact between the brush
and the slip ring? —
Repair or
replace the
brush holder assembly. Go to Step 3
3 Inspect the rotor coil on the generator.
Was there a short circuit in the rotor coil? —
Repair or
replace the rotor coil. Go to Step 4
4 Inspect the stator coil on the generator.
Was there an open circuit or the short circuit on the
stator coil? —
Repair or
replace the stator coil. Go to Step 5
5 Inspect the rectifier on the generator.
Was the rectifier defective? —
Replace the
rectifier Go to Step 6
6 Inspect the IC regulator on the generator.
Was the IC regulator defective? —
Replace the IC
regulator. Go to Step 7
7 Was the electrical load excessive? — Replace more
higher capacity generator. Go to Step 8
8 Are any DTC stored? — Go to indicated
DTC. Solved
14-4 Battery Unstable Charging Current
Step Action Value(s) Yes No
1 Was “Visual/Physical Check" performed.
—
Go to Step 2 Go to
visual/physical check
2 Inspect the brush contact condition on the generator.
Was there poor contact between the brush and the
slip ring? —
Repair or
replace the
brush and/or the slip ring. Go to Step 3
3 Inspect the rotor coil on the generator.
Was there the short circuit or an open circuit in the
rotor coil? —
Repair or
replace the rotor coil. Go to Step 4
4 Inspect the stator coil on the generator.
Was there an open circuit or the short circuit in the
stator coil? —
Repair or
replace the stator coil. Go to Step 5
5 Inspect the connection between the rectifier and
stator coil on the generator.
Was there a loose connection between the rectifier
and stator coil ? —
Repair the loose
connection. Go to Step 6
6 Inspect the IC regulator on the generator.
Was the IC regulator defective? —
Replace the IC
regulator. Go to Step 7
7 Are any DTC stored? — Go to indicated
DTC. Solved
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ISUZU KB P190 2007