3022591 - D72 CRUISE CONTROL SET+ CONTROL NOT WORKING

The Cruise Control system does not increase the speed when the knob is set to '+'.
For safety reasons, the Cruise Control is inhibited above a maximum speed and below a limit speed. If these speeds are exceeded, even because of a fault, the Cruise Control does not work any more
Results of the tests
1CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the diagnostic equipment (Examiner or other instruments) to the diagnostic socket.Check that there are no faults in the engine management control unitContinue to Step 2An error is detected in the control unitContinue following the instructions for the diagnostic equipment
Lack of dialogue with the control unitRestore the connection between the engine management control unit and the diagnostic connector: See   E5060  CRUISE CONTROL
2CHECK CRUISE CONTROL SELECTORAll OKProblems metOperation
Check that the Cruise Control contacts are workingContinue to Step 3Lack of continuityReplace stalk unit lever with built-in Cruise Control system control Op.   5580A10 
3SUPPLY CHECKAll OKProblems metOperation
With the ignition and Cruise Control knob set to 'ON' and '+', check that there is a voltage signal from the Cruise Control system control to the engine management control unit: See   E5060  CRUISE CONTROL Continue to Step 4No voltage foundRestore the connections: See   E5060  CRUISE CONTROL
4CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentThe fault persists: control unit faultyReplace the engine management control unit Op.   1056B82  Search for the fault starting from another symptom'