Anyone else have cold start transmission issues after the ECU flash?

I have had my 2017 SR5 for 6 days now and it's getting into nightmare territory. I had the sluggish shifting on the road and gear hunting so I called up my dealer who said there is a ECM update available and to bring in the truck.

Brought it in, they flashed the computer and I drove away. The truck felt much better on the road. The shifts were fast and smooth, exactly as it should have been.

But now on cold starts I am noticing a pretty clunky jerk from P to D or P to R. On top of this as I ease off the brake the vehicle is almost fighting with me to get going (sort of lunging forward or backward). This goes away as the vehicle warms up.

So I spoke to the service manager today and the long and short of it was that he said I need to give the vehicle a minute or so to warm up and that the high RPMs and jerking are normal for trucks...I explained to him I have owned 14-year old vehicles that shifted into drive cold more smoothly. He said he doesn't have an issue checking it but doesn't want me to be inconvenienced by having them take the truck. So his advice was to try warming it up for a few days to see how it goes.

I'm a reasonable person. I told him I would try to let it warm up for a minute or so for the next few days but I still feel a new vehicle should not behave like this. Also I advised him that this concerning cold start behavior started after the update. He knows he'll hear back from me if I am not satisfied.

Also called Toyota who basically told me they defer to the dealer's expertise when it comes to maintenance and technical issues and to follow along with their suggestions for now. Have a record opened with them though.

Am I crazy or should a brand new truck not behave like this on a cold start?

 

You're in very familiar territory. What I can tell you is that a "clunk" feeling when, say, coming to a stop when cold will often cause this thud/clunk feeling that feels like a delayed downshift after you've stopped. It can be annoying but it is normal and as far as I can tell it doesn't mean anything is "wrong"

The clunks from P to D or R to D to something COULD be related to transmission fluid levels. You can find several threads on this in the forum but you basically have to convince your dealer to manually check the tranny fluid b/c there is no dipstick. This is a pain for dealers b/c they have to get it to the proper temp (usually have to wait for it to cool and have to be meticulous to get a proper reading). If you can't get the dealer to check the fluid level for you, it can be DIY. As you read this I'm sure you're thinking THIS IS A BRAND NEW TRUCK and you should be able to rely on the dealer for your concerns but my best advice is to hang in there. Certainly some quirks with these trucks but most are solvable with some patience and then you'll love your truck again... I wouldn't shy away from a potential ECU update with OVTuned (Orange Virus) as it solves nearly any problems I had w/ my trucks shifting, power delivery, etc.,...

 

Mine (3 weeks old) does essentially the same thing. Meh, whatever.

 

Not normal, get the fluid level checked. Is the truck parked on an incline where it is parked over night?

 

I let it run a bit today and the trucks shifts smoothly into gear. Service manager seems to be right.

 

If the engine is running at high idle due to the cold and you put the vehicle in gear it's is going to lurch forward or reverse. Just letting the vehicle warm up until the high idle shuts down will solve your complaint.

 

had mine flashed and updated twice, issues kept coming back

 

Mine's been fine.

G.

 

Letting it warm up causes the low tranny fluid to expand enough to make the issue less noticeable....

Get the tranny filled correctly...!!

 

I'm starting to think so. It was close to minus 30 degrees Celsius without warming up so idk.

It' been driving okay today. We'll see how this goes.

 

Mine at 10k miles does the same thing. When cold and coming to a stop it feels like a delayed downshift and kinda thuds. This happened in my 11’ 4R as well.

 

Is parking on an incline bad?

 

I'd probably get a block warmer at that temp if it's every night. That's -22 for those south of the border.

Edit - For years all engines in cars since way back to the early days of combustion engines had a choke. It delivered more fuel to the engine when it was cold. In early cars you would have a knob on the dash to control it. You'll even find modern generator/lawn mower/whatever motors with a manual choke. Even 2 stroke bikes I think.

With EFI they mimic it in the software so the engine warms up faster, so you see higher rpm's until some sensor says the temp is high enough. The oil in the engine heats up pretty quickly. That sensor is software controlled and once it reaches a certain temp the engine drops quite a few rpm. You'll usually see it gradually happen.

Notice that the temp gauge doesn't show it's very hot, but the rpm's die down anyway. There is a lot of friction going on down there and the oil heats up very fast. Much faster then the coolant. Not sure what the spec is, but the thermostat probably needs to get up to about 185 degrees or so before the coolant is going to heat up (and heat up the cab).

Anyway, higher rpm's and gear changes generally mean lurches. It's always happened when I had an auto tranny in cold weather.

Edit2 - Now that I think about it, I did learn long ago to be a bit more careful with the clutch when it was really cold out (mostly have had MT's, until recently).

 

Really informative post, thanks! As for getting a block heater installed, it's not every day that it gets that cold here in Ottawa. For instance today is -6 (or 21.2 F). I might have to just get into the habit of letting her run on the really cold days.

 

I have read that it can cause this very issue. There is a thread on it someplace. I think the theory was that the incline caused the fluid to drain from the valve body and specifically the portion that controls 3-4 shifts.