Checking cruise control system (CCS) - diesel engines — AUDI

Requirements:

Vehicle diagnostic, testing and information system VAS 5051 connected up and vehicle self-diagnosis selected => Page
01-3
Engine idling

Attention:
Heed safety precautions => Page
01-1
.
Sequence of operations

Display on VAS 5051:

From list -1- select vehicle system "01 - Engine electronics".
Wait until next display appears.

Display on VAS 5051:

1 -
Engine control unit identification
2 -
Immobilizer control unit identification

Touch ▸ key.

Display on VAS 5051:

From list -1- select diagnosis function "08 - Reading measured value block".

Display on VAS 5051:

Use keypad -2- to enter "006" for "Display group number 006" and confirm by touching Q key.

Note:

On vehicles with automatic gearbox, cruise control system switch is only supplied with power at speeds in excess of 30 km/h and with selector lever set to 2, 3 or D. Power supply is then maintained even at idle, provided that gear (other than 1 or R) is engaged.

Perform test drive, exceeding a speed of 30 km/h once. Then leave engine running and selector lever set to 2, 3 or D.
Apply parking brake.

Display on VAS 5051:

Check display in zones -3- and -4-.

Test condition · Display zone 4
CCS released1) · 0
CCS on · 1

1)
If 255 is displayed: Activate cruise control system
=> Page
01-446

Test condition · Display zone 3
Switch B set to "OFF", engaged · 0 · 0 · 0 · 0 · 0 · 0
Switch B set to "ON" · 0 · 0 · 0 · 0 · 1 · 1
Switch A pressed "FIX" · 0 · 0 · 0 · 1 · 1 · 1
Switch B set to "ACTIV" · 0 · 0 · 1 · 0 · 1 · 1
Switch B set to "OFF", before engagement point (deceleration) · / / 0 · / / 0 · / / 0 · / / 0 · / / 0 · / / 1
Brake pressed · 0 · 1 · 0 · 0 · 1 · 1
Clutch pressed · 1 · 0 · 0 · 0 · 1 · 1

If readings do not match specifications:

Check wiring =>Page
01-444
.

Checking wiring

Unplug connector at CCS switch.

=> General Body Repairs, Interior; Repair Group 70; Dash Panel
General Body Repairs, Interior
Dash Panel

Connect appropriate test box V.A.G 1598.. to unplugged connectors of engine control unit.

=> Injection and Glow Plug System; Repair Group 23
Injection and Glow Plug System

Notes:

For connection of measuring instruments (e.g. voltage tester V.A.G 1527 B, portable multimeter V.A.G 1526 A), always make use of adapter set V.A.G 1594 A.
Contact numbers of connector coincide with socket numbers of test box.

Attention:
So as not to destroy electronic components, select required measuring range before connecting test leads and observe test conditions.
Check for open circuit and short to earth/positive in the following wiring.

Connector / Contact · Test box V.A.G 1598/.. / Socket
2 · =>Binder
3 · Current flow diagrams,
4 · Fault-finding/
5 · Electrics
6 · and
7 · Fitting locations

If necessary, eliminate open circuit in wiring/short circuit.