Checking the Set Function

Conditions for SET
The following conditions must be fulfilled before activation of the SET function in the Cruise Control systems control module will be possible:
Pin A (1): approx. 12 V
Pin B (2): approx. 12 V
Pin C (3): 0 V

The switch should be in the ON position.

1 Connect the BOB and check that about 12 V is present across terminals B (2) and A (1) of the Cruise Control connector and a good ground. Also check that no voltage (0 V) is present across terminal C (3) and a good ground when the SET button is held in the depressed position.







2 If the voltage readings are not OK, check that about 12 V is present across pin 4 of the switch connector and a good ground.
If the voltage is OK, continue with point 4.
3 If the voltage is not OK, check the wiring for continuity or a short circuit by measuring the resistance across the load side of the fuse and pin 4 of the switch connector.
If the resistance is > 1 ohm, rectify the fault.
4 Check the switch by holding it in the SET position and measuring the resistance across pins 4 and 2.
Set the switch in the ON position and measure the resistance across pins 4 and 1. Hold the switch in the RESUME position and take a reading across pins 4 and 3.
If the resistance reading obtained in any measurement is > 1 ohm, install a new switch.







5 If the resistance is ≤ 1 ohm, disconnect the negative battery cable and check the wiring for continuity or a short circuit by measuring the resistance across:
- pin 2 of the switch connector and pin B (2) of the Cruise Control connector.
- pin 3 of the switch connector and pin C (3) of the Cruise Control connector.
- pin 1 of the switch connector and pin A (1) of the Cruise Control connector.
If the resistance is > 1 ohm, rectify the fault.
6 If no fault has been found after carrying out the above checks, continue fault diagnosis as described "Before Control Module Replacement".