2004 ISUZU TF SERIES Workshop Manual

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ISUZU TF SERIES 2004  Workshop Manual 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

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ISUZU TF SERIES 2004  Workshop Manual 6F – 8   EXHAUST SYSTEM 
4JA1TC/4JH1TC 
The EGR system engine is controlled by ECM. Refer to “Engine driveability and emissions” section for detail. 
 
 
 
 
 
 
 
 
RTW46ELF001101

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ISUZU TF SERIES 2004  Workshop Manual 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 warm

Page 1804 of 4264

ISUZU TF SERIES 2004  Workshop Manual 6F – 10   EXHAUST SYSTEM 
4JA1TC/4JH1TC 
The EGR system engine is controlled by ECM. Refer to “Engine driveability and 
emissions” section for detail. 
  
 
 
RTW46EMF000701

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ISUZU TF SERIES 2004  Workshop Manual 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 i

Page 1806 of 4264

ISUZU TF SERIES 2004  Workshop Manual 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. B

Page 1807 of 4264

ISUZU TF SERIES 2004  Workshop Manual 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

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ISUZU TF SERIES 2004  Workshop Manual 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)