electric parts
CITROËN C5 III (RD_)

Help,

I have a citroen c5 III 2.0 bluehdi 110kw 2015 year. The start stop system does not work and I have a P1AA2 error – Voltage maintaining device. Open circuit or short circuit to earth of the supply line or of the earth between the voltage retaining device and power storage battery.

In the citroen service center they told me that the ECU unit was damaged, however, two citroen car service technicians told me that the fault was in the voltage regulator of the alternator (valeo 9807005580 – 06 12v 210A). I’ve looked everywhere and it seems that you can’t get a separate regulator, that is, you need to replace the entire alternator. However, I suspect the START/STOP VOLTAGE MAINTAINING DEVICE MODULE for which I do not know the location in the car 

 I would personally replace it, I just assume that it needs to be activated by software….

please help

Thank you.