Alternator P3
Error identification: The alternator is indicating that it is charging despite not being activated, i.e. when engine speed is below idling or engine is stationary.
Cause: Short circuit to +24V in the alternator circuit.
If the vehicle has a battery master switch, it may be an internal fault in the battery master switch or in the associated relay R70.
Notes: The power supply to the vehicle is regarded as unreliable. The battery charge warning lamp on the instrument cluster comes on and functions which have a high demand for electric current and therefore need a functioning charging system stop working. Examples of these functions are automatic dipped beam, seat heating and rear view mirror heaters.
Before renewing the alternator, see the Workshop Manual, TI 16-05 05 25, Troubleshooting and renewal table for alternators.
Action: Check that the Number of alternators parameter is correctly set.
Check that alternator charging is directly controlled by the engine control unit.
Check the electrical cables and alternator.
Before renewing the alternator, see the Workshop Manual, TI 16-05 05 25, Troubleshooting and renewal table for alternators.
If the vehicle has a battery master switch, check the battery master switch and associated relay R70.
Alternator P3
Error identification: The alternator is indicating that it is charging despite not being activated, i.e. when engine speed is below idling or engine is stationary.
Cause: Short circuit to +24V in the alternator circuit.
If the vehicle has a battery master switch, it may be an internal fault in the battery master switch or in the associated relay R70.
Notes: The power supply to the vehicle is regarded as unreliable. The battery charge warning lamp on the instrument cluster comes on and functions which have a high demand for electric current and therefore need a functioning charging system stop working. Examples of these functions are automatic dipped beam, seat heating and rear view mirror heaters.
Before renewing the alternator, see the Workshop Manual, TI 16-05 05 25, Troubleshooting and renewal table for alternators.
Action: Check that the Number of alternators parameter is correctly set.
Check that alternator charging is directly controlled by the engine control unit.
Check the electrical cables and alternator.
Before renewing the alternator, see the Workshop Manual, TI 16-05 05 25, Troubleshooting and renewal table for alternators.