Testing Cruise Control With Adapter

Special Tool:

Test Requirements
- Battery voltage > 11 V
- Stop lamp switch in order
- ABS in order

NOTE: It is essential that the adapter be used for cruise control testing. The use of other testers and measuring devices could result in destruction of the cruise control module. This examination tests the condition of the cruise control system out-side the control module. Sources of malfunctions can only be determined with the adapter in those cases in which the cruise control is completely inoperative. Malfunctions characterized by intermittent failure or unsatisfactory speed control (e.g. jerking) cannot be tested with the adapter; here you should proceed according to "Troubleshooting by Complaint". Should the test with the adapter indicate a defective component, check to ensure that all connectors have good contact (e.g. sockets must be tight) before replacing. Press together any loose sockets. Then recheck the implicated component

Preparations for Testing:
1. Check battery voltage; it must be at least 11 V to ensure successful completion of the test sequence.
2. Unscrew the cruise control control module from the control module bracket and remove the 14-pin coupling from the control module.
3. Connect test adapter 126 589 05 21 00 to the 14-pin coupling.





4. Switch on the ignition. The LED display symbols for the battery and speed indicator lamp km/h illuminate provided that no faults are present.





5. Press the "LED-TEST" button on the test adapter. Check whether all the LED displays illuminate. If no LED displays illuminate, check the voltage supply coupling and the assignment of the 14-pin coupling. (See wiring diagrams.)

)^OTest Steps 1 - 4:

Test Step 5: