Audi Workshop Service and Repair Manuals

Checking cruise control system - petrol engines with electronic throttle Sequence of operations l  Vehicle diagnostic, testing and information system -VAS 5051B- connected and vehicle self-diagnosis selected → Chapter l  Engine idling.

Display on -VAS 5051B-: –  From list -1- select vehicle system “01 - Engine electronics”. –  Wait until next display appears.

Display on -VAS 5051B-: 1 -  Identification of engine control unit 2 -  Control unit identification of immobilizer –  Touch → key.

Display on -VAS 5051B-: –  From list -1-, select function “08 - Reading measured value block”.

Display on -VAS 5051B-: –  On the keypad -2-, touch keys 66 for “Display group 066” and confirm the entry by touching the Q key.

Display on -VAS 5051B-: –  Check display in zone -2-.

Test condition	Display zone 2 with 4-digit display
CCS released 1)	“1”		0		0		0
Brake pedal pressed	1		0		“1”		“1”
Clutch pedal pressed	1		“1”		0		0
l  1) If value “0” is displayed: Activate cruise control system → Chapter.

Test condition	Display zone 2 with 8-digit display
CCS released 1)	0	0	0	0	“1”	0	0	0
Brake pedal pressed	0	0	0	0	1	0	“1”	“1”
Clutch pedal pressed	0	0	0	0	1	“1”	0	0
l  1) If value “0” is displayed: Activate cruise control system → Chapter.

–  Check display in zone -4-.

Test condition	Display zone 4 with 4-digit display
Switch -B- set to “OFF”, latched	0		0		0		0
Switch -B- set to “ON”	0		0		“1”		“1”
Switch -A- pressed “FIX”	0		“1”		1		1
Switch -B- set to “ACTIVATION”	“1”		0		1		1
Switch -B- set to “OFF”, before latching point (deceleration)	0		0		“0”		1

Test condition	Display zone 4 with 8-digit display
Switch -B- set to “OFF”, latched	0	0	0	0	0	0	0	0
Switch -B- set to “ON”	0	0	0	0	0	0	“1”	“1”
Switch A pressed “FIX”	0	0	0	0	0	“1”	1	1
Switch -B- set to “ACTIVATION”	0	0	0	0	“1”	0	1	1
Switch -B- set to “OFF”, before latching point (deceleration)	0	0	0	0	0	0	“0”	1

–  Terminate function “08 - Reading measured value block” by touching ← key. If readings do not match specifications: Checking wiring –  Unplug the connector at the cruise control system switch → Rep. Gr.94. –  Connect the 121-pin adapter cable -V.A.G 1598/31- (test box) to the unplugged multi-pin connectors of the engine control unit → Rep. Gr.24.   Note t  Use is always to be made for connecting measuring instruments (e.g. voltage tester -V.A.G 1527B-, portable multimeter -V.A.G 1526C-) of the adapter set -V.A.G 1594C-. t  The contact numbers of the multi-pin connectors coincide with the socket numbers of the adapter cable -V.A.G 1598/31- (test box).   Caution To avoid damaging electronic components, select the appropriate measuring range before connecting the test leads and heed the test conditions. –  Check for open circuit and short to earth or positive in the wiring → Current flow diagrams, Electrical fault finding and Fitting locations. –  Repair wiring if necessary.