Passat L4-1.8L Turbo (AWM) (2004)
Read measuring value block 4
->
1
2
3
4
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Read value indicated in display field 2. Specification: at least 11.5 V
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Press -> button.
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Press buttons -0- and -6- to select "End data transfer" function 06. Press -Q- button to confirm input.
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Switch ignition off.
If specified value is not obtained:
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Connect VAG 1598/31 adapter cable to control module wiring harness. Engine Control Module (ECM) is not connected.
Checking voltage supply at terminal 30
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Use multimeter and adapter cables from VAG 1594 connector test kit to measure supply voltage between sockets 1 + 62 of test box: Specification:
at least 11.5 V
If specified value is not obtained:
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Check wire connections to relay carrier according to wiring diagram:
Checking voltage supply at terminal 15
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Use multimeter and adapter cables from VAG 1594 connector test kit to measure supply voltage between sockets 2 + 3 of test box:
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Switch ignition on. Specification: at least 11.5 V
If specified value is not obtained:
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Check wire connections to relay carrier according to wiring diagram.
Check voltage supply via main relay
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Use multimeter and adapter cables from VAG 1594 connector test kit to measure supply voltage between sockets 2 + 121 of test box:
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Switch ignition on. Specification: at least 11.5 V
If specified value is not obtained:
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Check wire connections to relay carrier according to wiring diagram:
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Check activation wire from Engine Control Module (ECM) pin 21 to voltage supply relay for Motronic Engine Control Module (ECM) voltage
supply relay -J271- according to wiring diagram.
Terminal Resistance For CAN-Bus, Checking
Terminal resistance for CAN-Bus, checking
Vehicles with engine code ATW, AUG, AWM
Function
The Engine Control Module (ECM) communicates with all databus-capable control modules via a CAN databus.
These databus-capable control modules are connected via two data bus wires which are twisted together (CAN_High and CAN_Low), and exchange
information (messages). Missing information on the databus is recognized as a malfunction and stored.