Cruise Control: Service and Repair

Cruise Control System (CCS), Servicing


CAUTION!
Before working on the electrical system:
- Determine the correct coding for the anti-theft radio
- Disconnect battery Ground (GND) strap.
- After reconnecting the battery, re-code and check operation of the anti-theft radio. Also check operation of the clock and the power windows.


All cruise control system functions are controlled by the applicable Engine Control Module (ECM). The processing of electronic engine controls and cruise control functions are integrated in the ECM. Other than the cruise control switches on the steering column/multifunction steering wheel, the clutch and brake pedal switches and related wiring, there are no separate cruise control components to be serviced.

As all electronic throttle control operations are monitored by On Board Diagnostic (OBD), Diagnostic Trouble Codes (DTC) pertaining to engine electronics that are stored in DTC memory may be relevant to cruise control function.

Always check DTC memory first before troubleshooting (Function 02).

The operating status of the cruise control system, cruise control switches, brake and clutch switches can be checked using the following procedure:

Connecting VAG1551 Scan Tool (ST) and selecting functions

Test requirements:
- All fuses OK according to wiring diagram
- Voltage supply OK (at least 9.0 V)

Connect Scan Tool:
Data Link Connector (DLC) is located under instrument panel, left.







- Connect VAG1551 Scan Tool (ST) using VAG1551/13A adapter cable.

Indicated on display 1)


VAG - ON BOARD DIAGNOSTIC HELP
1 - Rapid data transfer
2 - Blink code output


1) Operating modes 1 and 2 are displayed alternately


NOTE:
- If the display remains blank, check VAG1551 voltage supply according to wiring diagram
- Additional operating instructions can be printed out by pressing the HELP button.
- The -> button is used to advance through the program sequence
- In "Rapid data transfer" operating mode 1, all vehicle control modules with OBD capability can be checked automatically using "Automatic Test Sequence" address word 00.


- Switch ignition on.
- Switch printer on by pressing PRINT button (indicator light in button lights up).

Special tools and equipment
- VAG 1551/1552 Scan Tool (ST) with VAG 1551/3 adapter cable, or VAS 5051 Vehicle Diagnostic Testing and Information System
- Connector test kit VW 1594
- Test box VAG 1598A
- Multimeter Fluke 83
- Wiring diagram

Test requirements
- Battery (B+acid/wateracid/water) voltage at least 11.5 V
- Ground connections on engine, transmission and battery OK
- Diagnostic Trouble Code (DTC) memory of Engine Control Module (ECM) checked and OK
- Fuse S5 OK
- Fuse S43 OK

Test sequence


NOTE:
- If cruise control is inoperative on models with 1.9L TDI engine, check if system is activated.
- If cruise control is inoperative on models with 1.8L Turbo engines, 2.8L VR6 engines and 2.0L engines, code AVH & AZG, check if system is activated.


- Connect VAG 1551/1552 Scan Tool.
- Switch on ignition
- Press buttons 0 and 1 to select Address word 01: "Engine electronics".

Display will appear as shown (gasoline engine example only)


06A906018AB Motronic M5.9.2 HS V06 ->
Coding 00000 WSC 00000


- Press -> button.

Display will appear as shown


Rapid data transfer HELP
Select function XX


- Press buttons 0 and 8 to select Function 08:
"Read measuring value block".
- Press Q button to enter input.

Display will appear as shown


Read measuring value block HELP
Input display group number XXX


For 1.8L, 2.0L and 2.8L gasoline engines:
- Press buttons 0, 6 and 6 to select "Display group 66".

For 1.9L TDI engine:
- Press buttons 0, 0 and 6 to select "Display group 06".

Continued for all engines:
- Press Q button to enter input.

Display will appear as shown


Read measuring value block XX ->
1 2 3 4


- Note values in display fields 2 - 4 and refer to the following engine type specific tables to interpret values:
- 1.8L Turbo and 2.8L VR6
- 2.0L (code AEG)
- 2.0L (codes AVH & AZG)
- 1.9L TDI


NOTE:
- The road speed signal in put to the ECM for cruise control function can be confirmed by performing a road test and observing that the km/h value indicated in display field 1 changes.
- Always observe the appropriate safety precautions during road test


1.8L Turbo and 2.8L VR6

2.0L (codes AVH & AZG)

Display Group 66:

2.0L (code AEG)

Display Group 66:

1.9L TDI

Display Group 06: