Reasons for Stop/Start being unavailable

[MacV50]

Hi folks

Stop/start hasn't been available on my car for a while due to the battery being too low in charge

Last night I needed to make a 75 mile round trip. During the outbound journey, I had the following messages in the DriveE menu

Electrical system i.e. battery charge too low
Outside temperature. It was -3C
Engine system

On the return journey, the Electrical system message was gone but I still had outside temp (-7) and Engine System

The only previous time I've seen Engine system is when the engine is still warming up or it's doing a DPF regen. Engine temp was right in the middle of the guage and I'm pretty sure it wasn't doing a regen as the MPG was OK so I was confused as to what might have caused it

I found the following on the Volvo website but it's not very detailed

I wondered if there was a comprehensive guide available that describes the conditions behind each message?

Cheers

[Deck1ng]

Hi, I’m pretty sure that I read on one of the platforms whether it was this one I cannot remember, but if the outside temp was “cold” , stop/start would not engage. I’m not 100% on that but sure I’ve read it.
Can’t help with msgs.
My experience with stop/start have been when unavailable, I bought a new smart charger then did that “Okey coky ”thing with the buttons ( push this one then push that one then say the Lord’s Prayer),and we where away again. But of course the reset may not be the same on all motors.

[MacV50]

Yes, I'm pretty sure it's unavailable below 0c and above 30c

I'm just confused by the engine system message unless it's related to the cold outside temp but I've seen both those messages on their own previously when the temp has been really cold

[Zebster]

Check for stored or pending DTCs?

[SwissXC90]

Originally Posted by MacV50

I wondered if there was a comprehensive guide available that describes the conditions behind each message?

These seem pretty clear to me:
The engine does not auto-stop in the following cases:

• The car has not reached approx. 10 km/h(6 mph) after starting.
• After a number of repeated auto stops, speed must again exceed approx. 10 km/h(6 mph) before the next auto stop.
• The driver has unfastened the seatbelt.
• The capacity of the starter battery is below the minimum permissible level.
• The engine is not at normal operating temperature.
• The ambient temperature is under -5 °C or above approx. 30 °C.
• the windscreen's electric heating is activated.
• The environment in the passenger compartment deviates from the set values.
• the car is reversed.
• The starter battery's temperature is below or above the permitted limit values.
• The driver makes sweeping steering wheel movements.
• The road is very steep.
• The bonnet is opened.
• The gearbox is not at normal operating temperature.
• When driving at high altitudes when the engine has not reached operating temperature.
• The gear selector is in ± position
• The ABS system has been activated.
• In the event of heavy braking (even without the ABS system having been activated).
• Many starts during a short period of time have activated the starter motor's thermal protection.
• Applies to cars with diesel engines: The exhaust system's particulate filter is full.
• A trailer is connected electrically to the car’s electrical system.

[MacV50]

Drove it today and it was available again. I did have engine system message for around 10 minutes after starting but that's pretty normal

Although the list above is comprehensive, it doesn't link the conditions to messages on the display. Most of those conditions shouldn't have applied after 35 miles of easy A roads. The only definite was that it was -7c so I'd expect the outside temp message

Outside temperature, driver unbelted, climate system, electrical system are all clear but engine system is so vague.