2014 Dodge Durango won't shift at -15F, says "service shifter"

[hemioiler]

That's not normal though. All kinds of people in Alberta were at -40F over the weekend and all their stuff still works? Even guys with the same ZF 8 speed.

I wonder if a fluid change (maybe even a different brand) would help there?

 

[wwillson]

That's not normal though. All kinds of people in Alberta were at -40F over the weekend and all their stuff still works? Even guys with the same ZF 8 speed.

I agree, but it's probably not worth it to me to replace the valve.

I wonder if a fluid change (maybe even a different brand) would help there?

Maybe I could put some ATF in it and it would loosen it right up!

I have done a trans spill and fill about every 20k miles since new. The current fluid is HPL low viscosity. I doubt a fluid change would do anything.

 

[dumkid]

The shifter knob may be electronic, but there is still a mechanical shifter and linkage that shifts the transmission into different drive modes, likely done by a solenoid.

You probably need to lube up that mechanism.

Most transmissions with electronic shifters just have solenoids inside to control prnd and a bolt or cable to emergency release the parking pawl

 

[spasm3]

I just talked to my mechanic friend Bill, who used a lifeline and called his trusty transmission shop. This shop does in-house rebuilds and really knows what they are doing. The trans shop said they have seen this many times in very cold conditions. It's a valve in the trans that sticks. Let the trans warm up and the problem will go away. So my guess that it was something in the shifter knob getting cold and sticking was wrong.

What to do about it? Nothing. They could replace the valve, but there is no point as this vehicle rarely sits outside. I left it sit in the garage last night (40F), no problem. In the future, I need to remember not to let it sit out in the cold or be willing to let it idle until the transmission warmer brings the temp up enough to unstick the valve.

I wonder If a stick on engine block warmer could be applied to the trans pan. Just for use in extreme conditions like this.

 

[wwillson]

I wonder If a stick on engine block warmer could be applied to the trans pan. Just for use in extreme conditions like this.

Probably, but these transmissions are heated by engine coolant, so it's just a matter of letting it warm up for a while.

 

[SubieRubyRoo]

I just talked to my mechanic friend Bill, who used a lifeline and called his trusty transmission shop. This shop does in-house rebuilds and really knows what they are doing. The trans shop said they have seen this many times in very cold conditions. It's a valve in the trans that sticks. Let the trans warm up and the problem will go away. So my guess that it was something in the shifter knob getting cold and sticking was wrong.

What to do about it? Nothing. They could replace the valve, but there is no point as this vehicle rarely sits outside. I left it sit in the garage last night (40F), no problem. In the future, I need to remember not to let it sit out in the cold or be willing to let it idle until the transmission warmer brings the temp up enough to unstick the valve.

Wonder if a PAO-based trans fluid would extend the temperature range of that solenoid?

 

[KrisZ]

Most transmissions with electronic shifters just have solenoids inside to control prnd and a bolt or cable to emergency release the parking pawl

Those still have a mechanical component and since it appears to be temperature related, I'm inclined to think something is binding or the dial switch is malfunctioning. Whether it can be serviced vs replaced that I do not know,

Found this useful ZF8 document.
The shifter appears to be serviceable, but the dial shifter does not.

Here is the Parking pawl mechanism. The solenoid is clearly internal, but perhaps the manual release cable is binding in cold weather and the solenoid cannot overcome it until it warms up?

https://akpphelp.ru/assets/template/redesign/files/guidelines/zf8hp45_70_rukovodstvo_manual.pdf

 

[OVERKILL]

I just talked to my mechanic friend Bill, who used a lifeline and called his trusty transmission shop. This shop does in-house rebuilds and really knows what they are doing. The trans shop said they have seen this many times in very cold conditions. It's a valve in the trans that sticks. Let the trans warm up and the problem will go away. So my guess that it was something in the shifter knob getting cold and sticking was wrong.

What to do about it? Nothing. They could replace the valve, but there is no point as this vehicle rarely sits outside. I left it sit in the garage last night (40F), no problem. In the future, I need to remember not to let it sit out in the cold or be willing to let it idle until the transmission warmer brings the temp up enough to unstick the valve.

But if the shifter works fine with the interior warmed and the transmission still cold, doesn't that point to your original diagnosis of it being something in the shifter assembly?

 

[wwillson]

But if the shifter works fine with the interior warmed and the transmission still cold, doesn't that point to your original diagnosis of it being something in the shifter assembly?

No, because I did let it idle to warm the engine before shutting it off, this also warms the transmission through the hot coolant that gets pumped back to the trans.

 

[hemioiler]

But if the shifter works fine with the interior warmed and the transmission still cold, doesn't that point to your original diagnosis of it being something in the shifter assembly?

Yes, and it also says "service shifter" not "service transmission".

These shifters have a physical component to them as well, they will prevent you from turning the knob under certain conditions. Could very well be something wrong with it.

 

[supton]

I realize the DTC says “service shifter” but what is the fault tree that leads to it? I am wondering if any discrepancy between shifter and trans status trips it, thus it could be either location.

 

[Astro14]

I realize the DTC says “service shifter” but what is the fault tree that leads to it? I am wondering if any discrepancy between shifter and trans status trips it, thus it could be either location.

I think that is exactly what is going on. A trouble code is a starting point, not a definitive diagnosis.

 

[D60]

Interesting setup. No freeze plugs, no draining coolant. Also looks like the heater is "dry" -- I guess it's just supposed to heat a sleeve in the head which in turn warms the coolant.

I would hope a Durango engine bay might be more forgiving?

 

[OVERKILL]

No, because I did let it idle to warm the engine before shutting it off, this also warms the transmission through the hot coolant that gets pumped back to the trans.

Ahhh, OK, I had assumed that the engine wasn't run in this scenario, that it was just the sun heating the cabin.

Guess easiest way to test would be to use a space heater to heat the cabin, keeping the powertrain cold?

 

[KrisZ]

This transmission needs a new pan for the filter change, correct? If so, that could be an opportunity to change the solenoid in the future.
Otherwise it doesn't sound like it makes a big impact to the OP.

 

[wwillson]

Guess easiest way to test would be to use a space heater to heat the cabin, keeping the powertrain cold?

I could, but I hope to never get the opportunity again. The cold we've had here is a rarity and the Durango normally sits in a heated garage.

 

[JTK]

Have you ever replaced the pan on this 8HP45? Reason I ask is, I've heard of some aftermarket pans causing gear select issues under certain conditions. Not sure if something gets blocked internally with these pans or what it could be. That's one of the reasons I opted not to use the aluminum autotechnica pan on my Ram 1500 some time back.

 

[wwillson]

Have you ever replaced the pan on this 8HP45? Reason I ask is, I've heard of some aftermarket pans causing gear select issues under certain conditions. Not sure if something gets blocked internally with these pans or what it could be. That's one of the reasons I opted not to use the aluminum autotechnica pan on my Ram 1500 some time back.

I have - https://bobistheoilguy.com/forums/t...5-transmission-filter-change-pictures.371040/

Replaced the pan with OEM

 

[eljefino]

I could, but I hope to never get the opportunity again. The cold we've had here is a rarity and the Durango normally sits in a heated garage.

If you have a solenoid getting weak this could be your first warning. The thing "should" be good down to arctic temperatures. They test cars in the arctic for this reason. That said, you might get it fixed when you definitely have to and not "maybe."

 

[sloinker]

Time for some Red Line tranny fluid. Has worked great on my vehicles that see extreme cold soak from time to time.