939003581 - D072 CRUISE CONTROL SET+ CONTROL NOT WORKING

The Cruise Control system does not increase the speed when the ring nut is turned to "SET+".

For safety reasons the Cruise Control is inhibited above a maximum speed and below a minimum speed. If these speeds are exceeded the Cruise Control no longer works

0	PRELIMINARY CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check, by carrying out a road test, then the vehicle speed is higher than 40 km/h when the SET+ ring nut is adjusted	Move on to Step 1	Speed below 40 Km/h	Bring the speed to above 40 Km/h
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the diagnostic test equipment (Examiner or other instruments) to the tester input.Check for the presence of faults in the engine management control unit	Move on to Step 2	1. Error detected in the control unit	1. Continue following the instructions for the diagnostic equipment
			2. No communication with the control unit	2. Restore the connection between the engine management control unit and the diagnostic connector:    See E5060 CRUISE CONTROL
2	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the diagnostic equipment to the engine management control unit and check that the SET+ position for the lever with the correct operaiton of the Cruise Control system contactsCheck the continuity of the Cruise lever contacts    See Test 5580AB Cruise Control SET + control check	Move on to Step 3	1.No continuity for lever contacts	1.Replace the Cruise Control lever assembly    Op. 5580A10 CRUISE CONTROL LEVER ASSEMBLY - R+R
			2.Power supply to lever interrupted	2.Move on to Step 3
3	SUPPLY CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	With the ignition key in the ON position and the Cruise Control in the ON position and the ring nut at "Set+", check that there is a voltage signal from the Cruise Control to the engine management control unit:    See E5060 CRUISE CONTROL	Move on to Step 4	No voltage detected due to broken wiring	Repair the connections:    See E5060 CRUISE CONTROL
4	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present by carrying out    See Test 5580AE CRUISE CONTROL OPERATION ROAD TEST	End of diagnosis	The fault persists: engine management control unit defective	Replace the engine management control unit    Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R