Automatic box of 320d 136cv broken

Hi, I bought the car second-hand and it made a ticking noise at low revs, I didn't think much of it. But today I was coming back from a trip and driving calmly at about 140 km/h it started losing power until I pulled up to the curb and it stalled and wouldn't restart. A symbol like a gear appeared on the dashboard. I know the gearbox has a problem, but what can you tell me?

Hi, I think you're talking about a BMW. If so, we'd need to know the year because there are several transmission models in these cars. Some are electronically controlled (I think that's your case) and others aren't, but it's always essential that the transmission fluid level is within the manufacturer's recommended range. As I mentioned, in some models the fluid level can be checked physically—the transmission has a dipstick—and in others it's checked electronically with a manufacturer's scanner.
Also, if you were hearing a noise, it's probably too late to worry about the lubricant level and there's likely mechanical damage. Therefore, you shouldn't start the vehicle until you find the problem. This could be one of the reasons; there could also be other problems that would give you the same symptom without the transmission being broken. Best regards, and I hope this helps.

I think if the car won't start it could be the transmission or the engine. I deduced it was the transmission because before it stalled, an "H" and a gear symbol appeared on the dashboard. They're bringing the car to the garage on Tuesday; I suppose the mechanic will know. I've looked at places to fix the transmission for between €1500 and €2000, but the garage will check it first. I'll let you know.

Ok I hope news I would like to send me what exactly the fault to take it into account in the future thanks and good luck