Volkswagen Passat 1995 Official Factory Repair Manual page 3226

Teves 20 GI Anti-lock Brakes (ABS) and Anti-lock Brakes with Electronic Differential Lock (ABS/EDL...
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During this period a self-test sequence is carried
out by the ABS control module to check the
following functions:
Battery positive voltage (B+) supply is checked;
must be at least 10.0 volts
The ABS control module, including valve
windings, is checked
An ABS wheel speed sensor (electrical) test is
carried out; fully completed at 20 km/h (approx.
12 mph)
ABS control module coding is checked
The On Board Diagnostic (OBD) program must
be initiated at the start of the troubleshooting
process by checking for stored malfunction
information using the VAG 1551 scan tool.
VAG 1551 scan tool
The Diagnostic Trouble Code (DTC) information
displayed by the scan tool is used in conjunction
with a DTC table, which lists possible causes of
the malfunction and suggested repairs.
With the Teves 20 GI system, the On Board
Diagnostic (OBD) program has been
complemented by the following functions:
Read Measuring Value Block
Code Control Module
Basic Setting (only required for vehicles with
EDL)
Output Diagnostic Test Mode
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12/7/2004