Volkswagen CJDA Workshop Manual page 453

vating the exhaust gas recirculation valve -N18- in a synchron-
ised manner, so that the extreme values for the exhaust gas re-
circulation system can be read in the measured value block.
Test prerequisites
● Fuses must be OK.
● The battery voltage must be at least 11.5 V.
● All electrical consumers must be switched off.
● Earth connections OK
● No leaks on intake and exhaust systems
● No faults on engine and fuel injection system or related to
compression.
● No faults must be stored in event memory
event memory.
● Coolant temperature must be at least 80°C, ⇒ display group
1, display zone 4.
Test procedure
– Connect vehicle diagnostic tester, and select engine control
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unit.
– Select diagnosis function "015-Access permissions".
– Carry out final control diagnosis, and activate exhaust gas
recirculation valve -N18-
The displays in display zones 3 and 4 must fluctuate within fol-
lowing control range:
● Specification in display zone 3: 180...370 mg/stroke
● Specification in display zone 4: 70...100%
Note
The activation of the valve can also be checked by touching it.
– Proceed with final control diagnosis until completed.
– Exit diagnosis function.
– Switch off ignition.
If the specifications are not obtained
– Check exhaust gas recirculation valve -N18-
– Check vacuum hoses for leaks. Vacuum hose schematic di-
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agram 334.
3.2 Checking exhaust gas recirculation
valve -N18-
Special tools and workshop equipment required
◆ Hand multimeter -V.A.G 1526- or multimeter -V.A.G 1715-
◆ Auxiliary measuring set -V.A.G 1594-
◆ Test box -V.A.G 1598/42- with adapter cable
-V.A.G 1598/39-1-
Workshop Manual for Diesel Engine (2.0 l/36-75 kW_EA 189) 05.2015
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89, final control diagnosis.
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Industriemotoren - Industrial Engines 2009 ▶
26, read
437.
3 Checking components and functions
3
437