Cruise Control Signal, Checking
NOTE: The Cruise Control system does not have components of its own except for the control switch. All functions are monitored and executed by the Diesel Direct Injection management system.
Special tools, workshop equipment, testers, measuring instruments and auxiliary items required.
- VAG 1551/1552 Scan Tool using VAG 1551/3 adaptor cable
- VAG 1598/22 Test Box
- Fluke 83 multimeter
- VW 1594 Adaptor kit
- Wiring diagram
Test sequence
- Connect VAG 1551/1552 Scan Tool. [1][2]Reading and Clearing Diagnostic Trouble Codes
- Start engine and let idle
- Press 0 and 1 buttons to select Address word 01: "Engine electronics"
Display will appear as shown
Rapid data transfer HELP
Select function XX
- Press 0 and 8 buttons 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 number XXX
- Press 0, 0 and 6 buttons to select "Display group 6"
- Press Q button to enter input
- Observe display in display zone 2
Specification display zone 1: Approximately road speed.
Read measuring value block 6 ->
0 km/h 000 000000 255
If display field 4 displays value 255
Read measuring value block 6 ->
0 km/h 000 000000 255
- Activate cruise control system
See Wiring diagrams, Electrical Troubleshooting and Component locations.
Vehicles with Automatic transmission
- Make a test drive and exceed 30 kph (19 mph) at least once, come to stop but do NOT switch OFF engine
- Place Transmission Range selector in 2, 3 or D
- Apply parking brake
NOTE: The Cruise Control system Voltage supply is switched ON at speeds in excess of 30 kph (79 mph) and with the Transmission Range selector in 2 3 or D. The Voltage supply is main tamed during idle as long as Drive mode is engaged (except for 1 and R).
Specification: display field 3: see table
Read measuring value block 6 ->
0 km/h 000 000000 255
Test conditions Display field 3
Switch B to OFF 000000
Switch B to OFF before 000001
switch-on point
Switch B to ON 000011
Switch B to Reserve 001011
Switch A pushed 000111
Brakes applied 010011
Clutch applied 100011
If specifications not obtained:
- Press -> button.
- Press 0 and 6 buttons to select Function 06: "End output"
- Press Q button to enter input
- Switch OFF ignition.
- Connect VAG 1598/22 Test Box to ECM harness connector.
- Test for open circuits or short circuits in wiring between Transmission Control Module and ECM terminal 23.
See Wiring diagrams, Electrical Troubleshooting and Component locations.
- Display Readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If DTC memory has been erased
- Create Readiness code. Monitors, Trips, Drive Cycles and Readiness Codes