125000476 - C13 THE GEARS DO NOT ENGAGE

Whilst driving, nothing above second is engaged irrespective of the mode (manual/automatic).
Results of the tests
0OIL LEVEL CHECKAll OKProblems metOperation
Check the oil level as described in See Test    See Test 2127B OIL LEVEL CHECKContinue to Step 2Level below the Max referenceTop up the oil levelContinue to Step 1
Level above the Max referenceReduce to the Max levelContinue to Step 2
1CHECK FOR OIL LEAKSAll OKProblems metOperation
Check that there are no oil leaks as described in See Test    See Test 2127C HYDRAULIC GEAR SELECTION SYSTEMContinue to Step 2Oil leaks detectedReplace/repair the parts concerned, and top up the oil levelContinue to Step 1
2CONTROL UNIT ERRORS CHECKAll OKProblems metOperation

Check that there are no control unit errors. In particular:

  • Engagement sensor error
  • Selection sensor error
  • Engine speed error
  • Clutch disc speed error
  • Vehicle speed error
  • Starting enablement relay error
  • (CAN) message reception error
  • CAN message transmission error
  • No accelerator pedal information error
  • Control unit broken error
  • Brake switch error
  • Microprocessor 2 error
Continue to Step 6Presence of one or more of the errors included in the listContinue to Step 3
3CHECKS ON FAULTS DETECTEDAll OKProblems metOperation
Check the faults in accordance with See Test    See Test 2127I What to do for error in Selespeed control unitContinue to Step 4Faulty connections (Engagement sensor, Selection sensor, Clutch disc speed, CAN errors, No acelerator pedal information)Repair/replace the wiringContinue to Step 4
Faulty connection (Engine speed)Repair/replace the part concernedContinue to Step 4
Errors in ABS control unitContinue according to the instructions for the diagnostic equipment
Errors in engine management control unitContinue according to the instructions for the diagnostic equipment
CAN communication problemsRestore correct communication, if necessary replacing faulty componentsContinue to Step 4
The change of state does not take place (starting enablement relay error)Check the brake pedal switch, its attachment and the state of the wiring connections. Restore/replace the component/wiringContinue to Step 4
One of the control units does not dialogue (Errors on CAN network)Repair/replace the control unit concernedContinue to Step 4
Having replaced the Robotized Gearbox control unit (Control unit broken error and/or microprocessor 2 error)Continue to Step 4
Faults detected (brake switch)Restore/replace the component/wiringContinue to Step 4
4SENSOR REPLACEMENTAll OKProblems metOperation
If there is a gear engagement sensor error and no faults are detected at the connections/wiring, replace it Op. 2127E42and check that the position reading is correct by carrying out a series of C.M.
In some cases, when the sensor is dismantled, there may be iron filings deposited on the sensor head
It is advisable to fit tool n° 1870753001 before removing the potentiometer from the hydraulic unit
If there is a gear selector sensor error and no faults are detected at the connections/wiring, replace it Op. 2127E40and check that the position reading is correct by carrying out a series of C.M.If there is a clutch disc speed error and no faults are detected at the connections/wiring, replace it Op. 2127E52and check that the position reading is correct by carrying out a series of C.M.
The sensor is located on the gearbox casing to the right of the reversing lights sensor
Continue to Step 5.
5AFTER THE CHECKS ON THE FAULTS DETECTEDAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsContinue to Step 6
6CLUTCH DISC SPEED SENSOR CHECKAll OKProblems metOperation
Check the clutch disc speed signal according to the See Test    See Test 2127A HYDRAULIC TRANSMISSION EXTERNAL LINKAGEContinue to Step 9There are problems with the sensor signalContinue to Step 7
7CHECK THE STATE OF THE CONNECTIONSAll OKProblems metOperation
Check the state of connections and wiring of the speed sensor.
In some cases, when the sensor is dismantled, there may be iron filings deposited on the sensor head
Continue to Step 8There are faults detectedRepair/replace the part that is not workingContinue to Step 9
8REPLACE THE CLUTCH DISC SPEED SENSORAll OKProblems metOperation
Replace the clutch disc speed sensor Op. 2127E52Continue to Step 9.
9AFTER THE CHECK ON THE CLUTCH DISC SPEED SENSORAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsContact Technical Service for further information on the problem