Volkswagen Passat 1995 Official Factory Repair Manual page 813

Motronic fuel injection system, servicing
http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW...
Idle check
Idle speed, ignition timing and oxygen sensor
factor (CO content) are not adjustable.
The idle speed is held to specification by
altering the ignition timing, Digital Idle
Stabilization (DIS) function.
The position of the distributor housing has no
influence on ignition timing.
CO content is regulated by oxygen sensor
control. Malfunctions in oxygen sensor control
are detected by the On Board Diagnostic
program and stored in Diagnostic Trouble Code
(DTC) memory.
Special tools, testers and auxiliary items
VAG 1551 Scan Tool (ST) with VAG 1551/3
adapter cable
Test conditions
Engine oil temperature 80 C (176 F)
minimum
Electrical consumers switched off (radiator
coolant fan must not run during the check)
Air conditioner switched off
Exhaust system must be free of leaks
No malfunctions stored in DTC memory
page 01-9
VAG 1551 Scan Tool (ST) connected
Page 29 of 94
24-23
6/12/2004