Technical Stop&Start not working

[xavgdt]

Hi all,

On my 2020 Ducato (120 2.3mj Euro6d) the stop&start function worked only a handful of times, and I can't figure out why.
I have read the status of the body computer twice (one month apart) with AlfaOBD and obtained the following

1 month ago
Shutdown inhibition from Stop&Start counters:
Climate control (NCL): 0
Outside temperature below threshold: 223
Outside temperature above threshold: 0
Battery charge below threshold: 0
Driver's seat belt not fastened: 312
Alternator not charged: 91
Bonnet switch: 0
Heated rear window: 0
Windscreen wiper high speed for 5 sec: 0
Battery sensor (IBS): 0
Driver's door open: 3
Battery efficiency below threshold: 138
Semi-automatic Parking Node (SPM): 1659
Battery temperature too low: 0
Battery voltage insufficient for startup: 0
Voltage stabilizer faulty: 14476
A/C manual climate control request: 0
Low consumption power supply mode: 20
S&S NBC startup relay faulty: 0
Now
Shutdown inhibition from Stop&Start counters:
Climate control (NCL): 0
Outside temperature below threshold: 223
Outside temperature above threshold: 0
Battery charge below threshold: 0
Driver's seat belt not fastened: 328
Alternator not charged: 91
Bonnet switch: 0
Heated rear window: 0
Windscreen wiper high speed for 5 sec: 0
Battery sensor (IBS): 0
Driver's door open: 3
Battery efficiency below threshold: 138
Semi-automatic Parking Node (SPM): 1730
Battery temperature too low: 0
Battery voltage insufficient for startup: 0
Voltage stabilizer faulty: 14498
A/C manual climate control request: 0
Low consumption power supply mode: 20
S&S NBC startup relay faulty: 0
It looks to me that the Semi-automatic Parking Node and the Voltage stabilizer faulty counters are disproportionately high, and they are the only one that increased in the past month. However I cannot figure out if they are the culprits and what to do to fix this! Does anyone have any idea?

Additionally I get the readings
Stop&Start: Absent
Start&Stop Presence: Not present

Any idea on what's going on?

 

[Greasytrucker]

If it’s still on it’s original battery it might just be that it’s detected that the battery is starting to weaken, start stop is normally the first thing to be disabled as a protection for the battery

 

[Declanmc1]

Is it possible just to remove battery (negative first) and change over without effecting any of the other vehicle electrics? Fiat Ducato based MH 2020.

 

[Greasytrucker]

Is it possible just to remove battery (negative first) and change over without effecting any of the other vehicle electrics? Fiat Ducato based MH 2020.

I don’t understand what you’re asking?

 

[Declanmc1]

I have a similar issue as above and will probably bite the bullet and change my cab battery. My vehicle is refusing to start after long drives, ie after refuelling at the diesel station. I usually have to jump with power pack or leisure battery. I am just wondering if removing/disconnecting the existing battery and therefore powering down the vehicle will effect any of the vehicle computers/management systems.

 

[Greasytrucker]

Short of resetting your speedo trip and losing preset radio stations as far as I’m concerned you’d just be doing exactly the same as if a garage swapped your battery. You can buy equipment to keep a 12v supply there whilst you do the swap but they’re quite expensive for what they actually do

 

[theoneandonly]

Have a read of this.

Starter Battery top up or removal /replacement

To avoid any problems with spiked or corrupted ECUs there are number of precautions to be taken. The SRS ECU (airbag), in particular, seems fairly prone to this and damage is often blamed on incorrect battery disconnection or jump starting...

www.fiatforum.com

 

[Reg 65]

The start stop on my 2021 Ducato rarely works since I fitted secondary batteries
But when the van stands for a few weeks in the winter I fully charge the batteries with a battery charger and that invariable causes the start stop to return
Probably the only time they get fully charged is when I charge them with the battery charger, because the smart alternator only attempts to fully charge them when the vehicle momentum is turning the engine.