New Beetle GLS L4-1.8L Turbo (AWV) (2001)
Engine Control Module: Testing and Inspection
CAN-Bus, Checking
With Manufacturer's Scan Tool
CAN-Bus, Checking
Function
The Motronic Engine Control Module (ECM) -J220- communicates with all data-bus capable control modules via a CAN-bus.
The data-bus capable control modules are connected and exchange information (messages) via two data-bus wires (CAN-High and CAN-Low) that are
twisted to each other. Missing information on the data-bus is recognized as a malfunction by the Motronic Engine Control Module (ECM) -J220- as well
as by other CAN-bus control modules.
The data-bus requires an adapting resistor to function fault-free. This central adapting resistor is located in the Motronic Engine Control Module (ECM)
-J220-.
Diagnosis via the CAN-bus wire is undertaken via the diagnostic interface for data-bus -J533- in the "Gateway".
NOTE: Control modules which are actively connected via data bus to the Motronic Engine Control Module (ECM) -J220- can be read in measured
value blocks 125 and 126.
Further information:
See Self Study Program "The CAN data bus".
Special tools and equipment
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VAG 1598/31 test box
-
Multimeter (Fluke 83 or equivalent)
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VW 1594 adapter set
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Electrical Wiring Diagram
Test conditions
-
Malfunction has been recognized by Data Bus On Board Diagnostic (OBD)
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All fuses must be OK
-
Battery voltage must be at least 11.5 V
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All electrical accessories, e.g. lights and rear window defroster must be switched off
-
Air conditioner must be switched off
-
Selector lever of the automatic transmission must be in "P" or "N" position
Test sequence
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Switch off ignition.
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Unlock Motronic Engine Control Module (ECM) -J220- connector and disconnect it.
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Connect VAG 1598/31 test box to Motronic Engine Control Module (ECM) -J220-. Control module wiring harness is not connected by this action.
-
Check centralized adapting resistor in Motronic Engine Control Module (ECM) -J220- by performing a resistance measurement between test box
Sockets 58 + 60
Specification: 60 to 72 Ohms
If the resistance value is outside the specified
range:
-
Replace Motronic Engine Control Module (ECM) -J220-.