Beetle L4-1.9L DSL Turbo (ALH) (1998)
Engine Control Module: Testing and Inspection
CAN-Bus, Checking
With Manufacturer's Scan Tool
CAN-Bus, checking
1
-
Engine Control Module (ECM)
2
-
ABS control module
3
-
Transmission Control Module (TCM)
-
Only vehicles with automatic transmission
4
-
Airbag control module
5
-
Instrument cluster
6
-
CAN-Bus
Function
The Engine Control Module (ECM) (item -1-) communicates with the ABS control module (item - 2-), the Transmission Control Module (item -3-), the
airbag control module (item -4-) and the instrument cluster (item -5-) via a CAN-Bus (item -6-).
At least two control modules capable of CAN-Bus are connected by two wires (CAN-High and CAN-Low, twisted together) and exchange information
(messages). Missing information on the CAN-Bus will be recognized as a malfunction by the ECM as well as by other CAN-Bus control modules.
All control modules have 120 W terminal resistors which make sure that the CAN-Bus can function without fault.
Special tools and equipment
-
Multimeter (Fluke 83 or equivalent)
-
VW 1594 adapter set
-
Wiring diagram
-
VAG1598/21 Test box
Test conditions
-
Malfunction has been recognized by CAN-Bus OBD
-
ABS control module coded to CAN-Bus operation
Test sequence