Disable the Start/Stop System

The Alpina B5 / D5 (G30/G31, 2017–2024) uses the BMW Auto Start-Stop system that shuts the engine off at a standstill. If you’d rather keep it running — in traffic, when manoeuvring, or before working under the bonnet — you can switch it off with the dash button.

Auto Start-Stop is a normal fuel- and emissions-saving feature, not a fault. It briefly stops the engine while you wait, then restarts it the instant you release the brake. On a high-output B5 or D5 the restart is quick and smooth, but some drivers still prefer to keep the engine running in stop-go traffic — switching it off for the drive is completely safe and the car reverts to its default on the next start.

How Auto Start-Stop Works on the B5 / D5

The system checks several inputs before it will cut the engine: the state of charge of the 12 V battery (monitored by an intelligent battery sensor), the engine and cabin temperature, the climate-control demand, and whether the car is genuinely stationary with the brake held. Because the engine has to be cranked again seconds later, the system will only stop it when there’s enough battery reserve and everything else is happy. If any condition isn’t met, the engine keeps idling — that’s the system protecting itself, not a defect.

Getting Ready

• Have the ignition on — you don’t need to be moving to press the button.
• Find the Auto Start-Stop switch near the gear selector or on the centre console; it carries an ‘A’ inside a circular arrow.
• If you’re about to open the bonnet for any work, switch the system off first so the engine can’t auto-restart.
• Remember the setting only lasts for the current drive — you’ll repeat it after each restart.

Turning Start/Stop Off

1. Press the Auto Start-Stop button on the dashboard (marked with the ‘A’ in a circular arrow).
2. The system is switched off until you turn it back on or restart the car.

It Resets Every Time You Start

Start-Stop re-enables automatically each time you start the engine. There’s no permanent off setting in the standard menus — press the button again after each start if you want it disabled.

If the Engine Won’t Stop at a Standstill

Even when active, the engine won’t cut unless the conditions below are met. If it never stops, work through these:

• The 12 V battery is sufficiently charged and the battery sensor is happy — short trips leave too little reserve to allow a stop.
• The engine and cabin are at temperature; from cold, or with the heater or air-con working hard, the engine stays running.
• The car is fully stopped with firm brake pressure — creeping forward cancels the stop.
• You’re on a gradient, or the steering is turned, so the car holds the engine on for control.
• The windscreen demist is running strongly, which can keep the engine on to power the heating.
• An ageing or weak 12 V battery is the most common reason it stops working; renewing and correctly registering the battery usually restores it.

What Happens Next

With the button pressed, the engine stays running at every stop for the rest of the journey — no cut-outs at lights, no restarts pulling away. Next time you start the car, Auto Start-Stop is armed again and the indicator returns, ready for you to leave on or press off as you prefer.

Frequently Asked Questions

How do I turn off Start/Stop on an Alpina B5/D5?

Press the Auto Start-Stop (‘A’ in a circular arrow) button on the dash, near the gear selector. The engine will then stay running at stops for the rest of that drive. It re-arms on the next start, so press it again each time you want it off.

Does it stay off permanently?

No. The car re-enables Auto Start-Stop every time you start the engine, and the standard menus don’t offer a permanent off. Pressing the button once at the start of each drive is the intended way to keep it disabled for that journey.

Why doesn’t the engine stop at lights?

Usually the battery charge or the engine/cabin temperature conditions aren’t met yet, or the climate control is working hard. A gradient, turned steering, or not holding the brake firmly will also keep it running. All of this is normal, deliberate behaviour.

Should I disable it for engine work?

Yes. Switch Auto Start-Stop off before working near the engine so it can’t auto-restart while you’re in the bay. For anything involving belts, the cooling fan, or moving parts, switch the ignition fully off as well.

Is Auto Start-Stop bad for the engine?

No — the car and its high-output engine were designed around it, with a starter and battery rated for the extra cycles. The 12 V battery does the most work, so keeping a healthy, correctly registered battery fitted matters more than switching the feature off.

Why is the Start-Stop light amber or flashing?

An amber or flashing indicator usually means the system has temporarily disabled itself — often because the battery charge dropped or a condition changed. If it stays lit as a fault, have the 12 V battery and charging system checked before assuming the system itself has failed.

If a Start-Stop fault light stays on, look up the code on autodtcs.com.