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DENSO COMMON RAIL SYSTEM (CRS). SERVICE MANUAL (2007) - page 4

Repair Section

2-116

7

Check the Exhaust Gas Recirculation (EGR)

Repair or replace the EGR system.

NG

system. (Refer to the EGR system check proce-

dure issued by the vehicle manufacturer.)

OK

8

Perform the accelerator pedal position sensor

Repair or replace the accelerator position sen-

NG

function check. (Refer to the accelerator posi-

sor and/or the corresponding circuit.

tion pedal sensor check procedure issued by

the vehicle manufacturer.)

OK

9

Check the boost pressure sensor and the corre-

Repair or replace the boost pressure sensor

NG

sponding circuit. (Refer to the boost pressure

and/or the corresponding circuit.

sensor check procedure issued by the vehicle

manufacturer.)

OK

10

Check the supply pump and the supply pump

Repair or replace the supply pump and drive cir-

NG

drive circuit. (Refer to the supply pump drive cir-

cuit.

cuit diagram issued by the vehicle manufac-

turer.)

OK

Troubleshooting complete

Repair Section

2-117

(10) Knocking, abnormal noise

Description

Abnormal combustion occurs, and a knocking sound is generated.

Possible Cause

• Engine

• Injector

• Glow control system

• Crankshaft position sensor

Clogged air cleaner element

1

Repair the glow control system. (Refer to the

Repair the glow control system.

NG

glow control system check procedure issued by

the vehicle manufacturer.)

OK

2

Check the crankshaft position sensor. (Refer to

Repair or replace the crankshaft position sensor

NG

the crankshaft position sensor check procedure

and/or the corresponding circuit.

issued by the vehicle manufacturer.)

OK

3

Check each injector. (Refer to the injector check

Repair or replace the injector and/or the corre-

NG

procedure issued by the vehicle manufacturer.)

sponding circuit.

OK

4

Check engine parts that may be a source of

Repair the engine.

NG

abnormal combustion.

OK

Troubleshooting complete

Repair Section

2-118

(11) Poor fuel economy

Description

More fuel than normal is being consumed.

Possible Cause

• Engine

• Injector

• Supply pump

Clogged air cleaner element

1

Check each injector. (Refer to the injector check

Repair or replace the injector and/or the corre-

NG

procedure issued by the vehicle manufacturer.)

sponding circuit.

OK

2

Check the supply pump and the supply pump

Repair or replace the supply pump and drive cir-

NG

drive circuit. (Refer to the supply pump drive cir-

cuit.

cuit diagram issued by the vehicle manufac-

turer.)

OK

3

Check parts that may be a source of poor fuel

Repair the engine.

NG

economy.

OK

Troubleshooting complete

R

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e

c

t i o

n

2-119

(12) Black Smoke

Description

Black smoke is being exhausted.

Possible Cause

• Injector

• Supply pump

• EGR system

• Engine ECU

• Electronic control throttle

• Rail pressure sensor

• Mass Air Flow (MAF) meter

• Boost pressure sensor

Clogged air cleaner element

1

Check for air cleaner clogging and/or damage.

Replace the air cleaner or repair the air duct.

NG

OK

2

Check the electronic control throttle and the cor-

Repair or replace the electronic control throttle

NG

responding circuit. (Refer to the electronic con-

and/or the corresponding circuit.

trol throttle check procedure issued by the

vehicle manufacturer.)

OK

3

Check the MAF meter and the corresponding

Repair or replace the MAF meter and/or the cor-

NG

circuit.

(Refer to the MAF meter check proce-

responding circuit.

dure issued by the vehicle manufacturer.)

OK

4

Check the Exhaust Gas Recirculation (EGR)

Repair or replace the EGR system.

NG

system. (Refer to the EGR system check proce-

dure issued by the vehicle manufacturer.)

OK

5

Check the boost pressure sensor and the corre-

Repair or replace the boost pressure sensor

NG

sponding circuit. (Refer to the boost pressure

and/or the corresponding circuit.

sensor check procedure issued by the vehicle

manufacturer.)

OK

6

Check the rail pressure sensor and the corre-

Repair or replace the rail pressure sensor and

NG

sponding circuit. (Refer to the rail pressure sen-

the corresponding circuit.

sor check procedure issued by the vehicle

manufacturer.)

Repair Section

2-120

OK

7

Check each injector. (Refer to the injector check

Repair or replace the injector and/or the corre-

NG

procedure issued by the vehicle manufacturer.)

sponding circuit.

OK

8

Check the engine ECU power supply. (Refer to

Repair the engine ECU power supply.

NG

the engine ECU power supply circuit diagram

issued by the vehicle manufacturer.)

OK

9

Check the supply pump and the supply pump

Repair or replace the supply pump and drive cir-

NG

drive circuit. (Refer to the supply pump drive cir-

cuit.

cuit diagram issued by the vehicle manufac-

turer.)

OK

Troubleshooting complete

Repair Section

2-121

(13) White smoke

Description

White smoke is being exhausted.

Possible Cause

• Fuel filter

• Injector

• Supply pump

• EGR system

• Engine ECU

• Electronic control throttle

• Rail pressure sensor

Clogged air cleaner element

1

Check the fuel filter.

Replace the fuel filter.

NG

OK

2

Check each injector. (Refer to the injector check

Repair or replace the injector and/or the corre-

NG

procedure issued by the vehicle manufacturer.)

sponding circuit.

OK

3

Check the Exhaust Gas Recirculation (EGR)

Repair or replace the EGR system.

NG

system. (Refer to the EGR system check proce-

dure issued by the vehicle manufacturer.)

OK

4

Check the supply pump and the supply pump

Repair or replace the supply pump and drive cir-

drive circuit. (Refer to the supply pump drive cir-

NG

cuit.

cuit diagram issued by the vehicle manufac-

turer.)

OK

5

Check the rail pressure sensor and the corre-

Repair or replace the rail pressure sensor and

sponding circuit. (Refer to the rail pressure sen-

NG

the corresponding circuit.

sor check procedure issued by the vehicle

manufacturer.)

OK

6

Check the electronic control throttle and the cor-

Repair or replace the electronic control throttle

NG

responding circuit. (Refer to the electronic con-

and/or the corresponding circuit.

trol throttle check procedure issued by the

vehicle manufacturer.)

OK

Troubleshooting complete

Repair Section

2-122

5.2 Other Malfunction Symptoms

Malfunctions caused by components other than the CRS

z There are occasions when a malfunction that appears to be generated by the CRS is actually caused by a different com-

ponent or system. For instance, engine mechanical parts and the fuel system may cause malfunction symptoms iden-

tical to symptoms generated by the CRS. When troubleshooting, do not simply assume that the source of a malfunction

is the CRS. Consider all causes should be exhaustively considered while verifying the list below.

Malfunction

Faulty Item

Cause

Action

Symptom

Intake system

Clogged air cleaner element

Clean or replace the air cleaner element.

Air mixed with the fuel system

Perform fuel system air bleeding.

Faulty fuel filter

Replace the filter.

Fuel system

Insufficient fuel

Add fuel and perform fuel system air

Insufficient

bleeding.

Power

Improper fuel

Switch to the correct fuel.

Compression pressure abnormality

Refer to the engine repair manual.

Engine

Piston, cylinder liner and/or piston ring

Other

Overheat

Intake system

Clogged air cleaner element

Clean or replace the air cleaner element.

Insufficient fuel

Add fuel and perform fuel system air

bleeding.

Improper fuel

Replace the filter.

Fuel system clog

Clean the fuel system.

Fuel system

Air introduction through fuel system con-

Tighten all connections.

Faulty starting

nection points

Fuel filter clog

Replace the fuel filter.

Loose injection piping connections

Tighten connecting nuts.

Faulty battery

Check the battery.

Electrical sys-

Faulty starter wiring

Replace the starter wiring.

tem

Loose battery cables

Tighten the battery terminal connections,

or replace the cables.

Electrical sys-

Faulty starter operation

Replace the starter assembly.

tem

Faulty glow plug system

Replace the glow plugs.

Lubrication

Excessive engine oil viscosity

Replace with oil of appropriate viscosity.

system

Burnt pistons

Replace the piston, piston ring and cylin-

Faulty starting

der liner.

Engine

Burnt bearings

Replace the bearing and crankshaft.

Low compression pressure

Overhaul the engine.

Ring gear damage

Replace the ring gear and/or starter pin-

Other

ion gear.

Repair Section

2-123

Malfunction

Faulty Item

Cause

Action

Symptom

Poor valve clearance

Adjust the valve clearance or replace the

bearing.

Poor valve seat contact

Break in, or replace the valve and valve

Faulty idling

Engine

seat.

Low coolant temperature

Perform warm-up operation.

Large difference in cylinder-to-cylinder

Overhaul the engine.

compression pressure

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