Passat Sedan L4-2.0L Turbo (BPY) (2007)
Engine Control Module: Testing and Inspection
Terminal Resistance For CAN-Bus, Checking
Terminal Resistance For CAN-bus, Checking
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.
Trouble-free operation of the CAN-bus requires that it have a terminal resistance. This central terminal resistor is located in the Engine Control Module
(ECM).
Recommended special tools and equipment
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V.A.G1526 multimeter or V.A.G1715 multimeter
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V.A.G1594 connector test kit
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Wiring diagram
Test requirements
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A CAN-bus malfunction was recognized via On Board Diagnostic (OBD).
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Data Bus On Board Diagnostic Interface -J533- must be OK.
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Ignition switched off.
Test sequence
Observe safety precautions.
Observe rules for cleanliness.
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Connect 94-pin connector of test box to Engine Control Module (ECM). See: Computers and Control Systems/Testing and Inspection/Component
Tests and General Diagnostics/Component Tests (VAG Code Tests)/Test Box, Connecting For Wiring Test
Harness connectors of control module wiring harness are not connected for this.
Checking terminal resistance
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Check terminal resistance in Engine Control Module (ECM) between sockets 67 and 68 of test box.
Specified value: 60.0 to 72.0 Ohms
If specified value is not obtained:
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Replace Engine Control Module (ECM) -J623-.
If specified value is obtained:
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Eliminate malfunction in Data-Bus wires or in other Data-Bus components according to wiring diagram
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Erase DTC memory of Engine Control Module (ECM).
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Generate readiness code.