Page 1801 of 4264
EXHAUST SYSTEM 6F – 7
GENERAL DESCRIPTION
This system controls the formation of NOx emission by recirculating the exhaust gas into the combustion chamber
through the intake manifold.
4JA1T(L):
The two EGR valves are controlled by two Vacuum Switching Valve (VSV) controlled by EGR controller according to
signals from various sensors.
The amount of EGR depends on the number of engine rotations and the opening of the accelerator.
RTW46ELF001201
Page 1802 of 4264
6F – 8 EXHAUST SYSTEM
4JA1TC/4JH1TC
The EGR system engine is controlled by ECM. Refer to “Engine driveability and emissions” section for detail.
RTW46ELF001101
Page 1803 of 4264
EXHAUST SYSTEM 6F – 9
EGR SYSTEM DIAGRAM 4JA1T (L)
RTW46AMF000301
EGR System Operation
Inspect EGR valve motion visually while changing engine RPM under no load condition after warming-up.
Inspection point (Engine RPM)
RPM Idling
900 960 2000 3250
Engine Front Side VSV-1 ON ON ON OFF
Engine Rear Side VSV-2 ON OFF ON OFF
ON means VSV should receive signal to move EGR valve.
OFF means VSV shouldn’t receive signal to move EGR valve.
Page 1804 of 4264
6F – 10 EXHAUST SYSTEM
4JA1TC/4JH1TC
The EGR system engine is controlled by ECM. Refer to “Engine driveability and
emissions” section for detail.
RTW46EMF000701
Page 1805 of 4264
EXHAUST SYSTEM 6F – 11
INSPECTION
4JA1T(L)
Vacuum switch valve (VSV)
Use a circuit tester to measure the V.S.V. resistance.
V.S.V Resistance at 20°C
37 ~ 44
If the resistance is not within specification, replace it.
EGR Valve
Apply vacuum to the EGR valve, check to see the valve
operation.
Negative Pressure
4JA1TC/4JH1TC
RTW46ESH000301
EVRV
Use a circuit tester to measure the EVRV resistance.
EVRV Resistance at 20°C
14
If the resistance is not within specification, replace it.
EGR Valve
Apply vacuum to the EGR valve, check to see the valve
operation.
Negative Pressure 4JH1TC
Less than 250 mmHg Not operation
More than 300 mmHg Operation
Negative Pressure 4JA1TC
Less than 100 mmHg Not operation
More than 170 mmHg Operation
Less then 180 mmHg Not operation
More than 240 mmHg Operation
Page 1806 of 4264
6F – 12 EXHAUST SYSTEM
EGR COOLER (4JA1TC/4JH1TC EURO-III MODEL)
REMOVAL AND INSTALLATION
RTW46EMF000201
Removal Steps
1. Bolt
2. Gasket
3. Bolt
4. Gasket
5. Bolt
6. Bolt
7. EGR Pipe Assembly
8. Gasket
9. Bolt
10. EGR Cooler Assembly
11. Gasket
12. EGR Cooler Adapter
Removal
1. Bolt
2. Gasket
3. Bolt
4. Gasket
5. Bolt
6. Bolt
7. EGR Pipe Assembly
8. Gasket
9. Bolt
10. EGR Cooler Assembly
11.Gasket
12.EGR Cooler Adapter
Page 1807 of 4264
EXHAUST SYSTEM 6F – 13
RTW46EMF000901
Installation steps
1. EGR Cooler Adapter
2. Gasket
3. EGR Cooler Assembly
4. Gasket
5. Bolt
6. EGR Pipe Assembly
7. Bolt
8. Bolt
9. Gasket
10. EGR Valve Assembly
11. Bolt
12. EXH Manifold
13. Gasket
14. Bolt
Page 1808 of 4264
6F – 14 EXHAUST SYSTEM
Installation
1. EGR Cooler Adapter
2. Gasket
3. EGR Cooler Assembly
4. Bolt
Tighten the bolts to the specified torque.
EGR adapter bolt torque Nm(kgm/lb ft)
27(2.8/20)
5. Gasket
6. EGR Pipe Assembly
7. Bolt
Tighten bolts temporarily.
8. Bolt
Tighten bolts temporarily.
9. Gasket
10. Bolt
Tighten bolts temporarily.
11.Gasket
12.Bolt
Tighten bolts temporarily.
Finally tighten all bolts to the specified torque.
Confirm that there is no misalignment on the sealing
surface.
Bolt torque (Cooler-pipe) Nm(kgm/lb ft)
27(2.8/20)
Bolt torque (Cooler-bracket) Nm (kgm/lb ft)
24(2.4/17)
Bolt torque (Adapter-EGR valve) Nm (kgm/lb ft)
27(2.8/20)
Bolt torque (Pipe-manifold) Nm (kgm/lb ft)
27(2.8/20)