199000798 - H026 NO ELECTRIC STEERING POWER ASSISTANCE WITH FAILURE WARNING LIGHT NOT ON

The Customer complains of failed operation (hardness when steering or loss of performance) WITHOUT the failure warning light coming on
Test results
0PRELIMINARY CHECKAll OKProblems encounteredOperation
The Customer complains of a loss in performance without the warning light coming on, especially after short radius steering manoeuvres.Move on to Step 1The same as the Customer.DO NOT replace the Electric Steering assembly. The system is working perfectly. The thermal protection has intervened during the operation of the electric steering.
1VISUAL INSPECTIONAll OKProblems encounteredOperation
With the panel on, the steering wheel is rotated simultaneously to the left or the right. Check whether the problem is solved by calibrating the system.Move on to Step 2The problem persists or it is impossible to carry out the calibration.Replace the Electric Steering assembly.    Op. 4110D20 STEERING ELECTRICAL CONTROL DEVICE - R R
2VISUAL INSPECTIONAll OKProblems encounteredOperation
Strong steering wheel vibrations with the vehicle stationary, constantly, or in certain steering positions.Move on to Step 3.Steering box defective.DO NOT replace the Electric Steering assembly
No problems are detected in the steering box.Replace the Electric Steering assembly.    Op. 4110D20 STEERING ELECTRICAL CONTROL DEVICE - R R
3CORRECT OPERATION CHECKAll OKProblems encounteredOperation
Connect the Examiner diagnostic equipment and check, in the "Parameter Reading" mode for the Electric Steering Node, that there are no errors and that the parameters are present.Move on to Step 9.Impossible to connect to the control unit.Move on to Step 4.
Low battery voltage parameter reading.Move on to Step 8.
Presence of errors.Move on to Step 10.
4ELECTRICAL POWER SUPPLY CHECKAll OKProblems encounteredOperation
Check the electricity supply to the Electric Steering Node is correct With the panel off, check for a voltage of around 12.5V at the blue connector. With the panel on, check for the same voltage at PIN 1 of the black connector for the CAN line signals.    See E7045 ELECTRIC STEERING Move on to Step 5.Battery voltage faulty.Move on to Step 8
Fault in positive electrical supply and/or earth.Replace the component causing the problem (in the case of a fuse, find out what caused the damage).
5ELECTRICAL CONNECTIONS CHECKAll OKProblems encounteredOperation
Check the electrical connections for the Electric Steering Node and the Body Computer searching for any loose connections creating occasional breaks in supply. In particular, make sure that every PIN is correctly connected and fitted in place.    See E7045 ELECTRIC STEERING Move on to Step 6.Electrical connections not operational.Renew the damaged electrical connections.
6NO RESIDUAL VOLTAGE CHECKAll OKProblems encounteredOperation
Start up the engine and then switch it off. At this point, with the panel off, check that the voltage at PIN 1 of the black connector for the CAN line signals is effective 0V.    See E7045 ELECTRIC STEERING Move on to Step 7.The voltage at PIN 1 with the panel off is more than 0 V.DO NOT replace the Electric Steering assembly. Electrical equipment problem. Contact TESEO
7CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
Recheck the possibility of connecting to the Electric Steering Node using the Examiner.Move on to Step 3.Impossible to connect to the control unit.Replace the Electric Steering assembly.    Op. 4110D20 STEERING ELECTRICAL CONTROL DEVICE - R R
8BATTERY ELECTRICAL CHECKAll OKProblems encounteredOperation
Check the following, in order:- Battery voltage correct.- Battery wiring correctly fastened.    See E1010 POWER SUPPLY End of diagnosis.Services battery voltage faulty.Restore the correct operation of the battery.
Loose connections detected in the Electric Steering Node supply circuitRepair the wiring
9ELECTRICAL CONNECTIONS CHECKAll OKProblems encounteredOperation
Check the electrical connections for the Electric Steering Node searching for any loose connections creating occasional breaks in supply. In particular, make sure that every PIN is correctly connected and fitted in place. Take GREAT care over the positive battery terminal leading to the 70 A fuse for the electric steering (left terminal). If it is secured but NOT correctly fitted in place, disconnect it and fasten it correctly.    See E7045 ELECTRIC STEERING End of diagnosis.Electrical connections not operational.Renew the damaged electrical connections.
10CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
Check for the presence of the following error using the Examiner in the Electric Steering Node ambient:- C1005, bulb failure.End of diagnosis.Bulb faulty.DO NOT replace the Electric Steering Assembly. Check for the presence of similar errors in the Instrument Panel. Check the operation of the Instrument Panel and Body Computer Node Check the CAN connections.