Technical 2017 Ducato 2.3Multijet2 with Comfort-matic gearbox - high current when switching ignition on

[dave987]

Turning ignition key to the 'MAR' position (engine not running) sees a current of 88Amps pulled from vehicle battery. This seems very high to me. I understand the Glow Plugs could pull about 24Amps, so where is the other 64Amps going?

As a consequence of this, the battery voltage drops to 11.5V within a few seconds and the TRW Airbag ECU module reports error code B0100-49 (low voltage).

 

[panlap]

My 2018 2.3 with comfort-matic causes a dramatic drop in starter battery voltage when you turn on the ignition or even just opening the driver side door. It seems to be due to the comfort-matic actuating hydraulic pump priming the system ready for selecting gears should you want to drive off immediately ( you can hear the faint whistle of the pump for 3 seconds or so when you open the drivers door to get in ).
The volt-drop does not seem to affect anything other than the victron smart shunt I have fitted ( to monitor the motorhomes habitation battery state-of-charge ) and shows around 11.5v in the 'lowest starter voltage' record. I was puzzled by this at first as I have never seen the starter battery lower than 12.5v and eventually realised this huge surge of current as the ecu prepares systems for startup even before the ignition key is turned on and only lasts a few seconds but it does pull down the voltage to around 11.5v for a short time.
I have assumed all comfort-matics do this ?.