There was a problem in earlier models with the 4EAT that the thrust washer in the torque converter would cause a stall in a hot transmission. I was seeing this symptom so I added a transmission cooler and haven't seen the problem since.

You may want to see if you can monitor transmission fluid transmission temperature in your car to see if there is a correlation.

 

It's the CVT model but yeah that is slightly annoying as I previously had a cheapy ELM327 scanner that I used with my android phone but it started not being able to talking to the ECU so I thought it was broken and got a new and different cheapy but this one doesn't communicate to multiple cars and two different Pixel Phones so it's either I got very unluckly with my cheap OBD scanners or there is an issue with pixel phones with regards to bluetooth.

Would you reckon this would happen to CVT models as well? Only a few occasions after a grocery run that on the first 2 times of trying to start the car that it would turn over but stall immediately. But lately it definitely only happens when I'm just about to park it. And the engine is definitely warmed up too.

 

The source of the problem I was describing is limited to temperature in the transmission. A long trip over hills results in sustained elevated temperature in the transmission components. You are telling me now that the problem may not be related exclusively to elevated temperatures.

The stall at the grocery store is different than after a long trip. So how long of a trip would you say is involved when the car stalls in the driveway?

 

Hey @donkpow I think you are right on the money here I tried to read more threads that referred to the thrust washer and I think this is likely to be it.

Just on the elevated temperatures, it stalled just a few days ago even when I drove about 2 mins to my next door neighbor so that shouldn't affect the temperatures too much.

I took this off a Car tuning website "we’ve repaired a number of these converters and seen both mild and severe symptoms. Some vehicles simply dip to 300–400 RPM briefly before recovering. Others stall cleanly, consistently, and without any warning lights. In every case, the fault traces back to the same internal wear pattern."

On mine when it stalls it definitely stalls cleanly which was also one of the reason why it didn't feel like a manual car that stalled without stepping on the clutch.

Would you know if it is likely to be an expensive repair? I have always done my own DIY but I am in Australia just for a few months and don't have tools on hand. This is also frustrating as I have performed a drain and fill on the CVT recently but the stalling issue was so intermittent that it is hard to flag even during a pre purchase inspection

 

It is definitely an expensive repair. It doesn't look to me like we have pinned this down. I've been seeing a near stall in my car lately. It has to do with the A/C compressor. With cycling of the compressor on, the car tries to stall. It doesn't happen all the time. I used some spray cleaner in the throttle body this last weekend so I may see some change in behavior. You say a "clean stall". Is this like turning the key off? Both the compressor related issue and the thrust washer problem are actually an unexpected load being placed on the system. So the engine is getting dragged down fairly quickly. I'd say faster than what the system is prepared to cope with. It's not an immediate stall. Not like turning the key off or pulling a wire on like the ignition coil.

 

The stalling I encountered had no shuddering or jolting it mostly happens when I am rolling into my parking spot. The dashboard would light up like a Christmas tree and a constant beep would come on.
Just like the beep you hear when you leave the headlight on and take the key out.

It also happened on a few occasions previously when shifting from Park to Reverse or Drive to Park which is also like an unexpected load.

It hasn't happened to me in traffic light stops yet fortunately but previously on at least 2 occasions if I drove maybe 30 mins and stop somewhere it is likely to stall at the end of the journey when I try to park it.

Also just on the AC compressor I believe it's likely to do with the extra load that tips it closer to stalling.

 

"no shuddering or jolting"
Shuddering would suggest the transmission not disengaging. So that's good.

"it mostly happens when I am rolling into my parking spot."
I assume with the transmission in gear?
When you changed the CVT fluid, did you do it to correct a problem? Who did the fluid change; dealer, independent shop, your neighbor, etc.?

"Just like the beep..."
Okay, that's normal. The key's on, the engine's not running, the tone exists.

"It also happened on a few occasions previously when shifting from Park to Reverse or Drive to Park which is also like an unexpected load."
In this shifting situation, did the stall occur in interval of change. Or is it stalling once you get to the new gear? This is what's bring me back to the transmission question.

 

Yes it happens with the transmission in gear, never when I am in motion but often always when I roll into a stop with my feet on the brakes and I'll observe it closer next time but it is around the time where my feet is on the brake and I am shifting from D to Park

No I perform the CVT fluid drain and fill because I purchased that car recently and it has not been performed before it's mileage is now around 132K KM so that was just me trying to be proactive.

It was done at a mechanic and I only notice the stalling afterwards.

But because I perform the drain and fill shortly after I got the car I can't say with certainty that it hasn't stalled before the service.

 

There's many reasons why a car will stall as described.

It could be clogged EGR valve or a brake booster issue.

I'd look into other causes before chasing a transmission issue.

 

The brake booster adds more power to your brake pedal. That's why they used to call these brake systems "power brakes". The booster uses engine vacuum to "boost" pedal pressure.

EGR is "exhaust gas recirculation". The valve should generally by closed at idle. If it is stuck open at idle, the car will probably be running rough.