Volkswagen CJDA Workshop Manual page 433

⇒ P age
Checking data bus
3.1 Checking voltage supply for engine
control unit
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 1598/39-2-
◆ Current flow diagram
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
Test procedure
– Using adapter cable -V.A.G 1598/39-2-, connect test box
-V.A.G 1598/42- to wiring harness and to control unit
⇒ P age
24.
– Connect multimeter to following test box contacts using test
leads from -V.A.G 1594- to measure voltage:
◆ 1 + 87
◆ 2 + 87
◆ 4 + 87
● Specification: approx. 0.0 V
– Switch on ignition.
– Measure voltage again between following test box contacts:
◆ 1 + 18
◆ 1 + 49
◆ 2 + 18
● Specification: approx. battery voltage
– Switch off ignition.
– Connect multimeter to following test box contacts using test
leads from -V.A.G 1594- to measure voltage:
◆ 1 + 92
◆ 2 + 92
◆ 4 + 92
● Specification: approx. battery voltage
If the specifications are not obtained
Workshop Manual for Diesel Engine (2.0 l/36-75 kW_EA 189) 05.2015
424.
Industriemotoren - Industrial Engines 2009 ▶
3 Engine control unit -J623-
3
417