Transmission question (1 Viewer)

[kossykoss]

Hello everyone. I’ve been using MUD as a resource for my 2013 LX over the last year but this is my first post.

I took a trip to Death Valley eariler this month and while descending this gnarly mountain I tripped a P2716 code for my shift solenoid in the trans. This lead to a flashing 4Lo and CEL and my trans hard shifting. Manually activating the solenoid got it to start working again and cleared the code. But before that fix, I was under the truck unplugging all the connections and I noticed a spring loaded metal button with a metal wire hanging off of it. The button is recessed into this hexagon shaped housing. And on each face of the hexagon are holes to allow for a cotter pin to go through and hold the button pushed in. I figured the metal wire hanging off of it was supposed to be pushing the button in, so that’s what I did. Does anybody know what this button is for? Should it be pushed in at all times? Or should I take that wire out? I’ve looked around and haven’t been able to track down what it does. Pictures are attached. Thanks guys! And hopefully this is being posted on the right spot. I’m hopeless with forums lol

 

[GOLIGHTLY]

That’s a little… “grenade-y” for my liking.

 

[LvCruiserNewb]

I believe that's the transmission cooler thermostat. See this thread on doing a transmission flush and it will show the part and describe its function. Depressing the button overrides the thermostat and forces transmission fluid through the cooler all the time I believe instead of only opening when above the set temperature.

Complete Transmission Flush DIY - VIDEO

I finally pulled together the video I took while completing a complete transmission fluid flush. Most of you know the dealer's service typically consists of draining and refilling the pan only. This only introduces 3-4 clean quarts of fluid in the system. I went through 14 quarts of fluid...

forum.ih8mud.com

 

[lndshark]

That is the transmission thermostat housing. When the pin is in place, fluid is sent through the trans cooler. Unpinned and it will bypass the cooler until the thermostat opens completely. For vehicles in cooler climates, the pin is removed so that the ATF warms faster.

 

[kossykoss]

That is the transmission thermostat housing. When the pin is in place, fluid is sent through the trans cooler. Unpinned and it will bypass the cooler until the thermostat opens completely. For vehicles in cooler climates, the pin is removed so that the ATF warms faster.

Perfect! So living in SoCal, I should probably just leave the pin in place? I’ll probably graduate from sketchy wire to an ACTUAL cotter pin though. lol

 

[mceagle555]

Perfect! So living in SoCal, I should probably just leave the pin in place? I’ll probably graduate from sketchy wire to an ACTUAL cotter pin though. lol

Did you buy your rig used? If so, I 100% guarantee the previous owner had maintenance being done (or did it himself) to flush the transmission fluid and they simply forgot to remove the makeshift pin. (I personally use a paperclip, which that looks similar to).

Just remove it

 

[kossykoss]

Did you buy your rig used? If so, I 100% guarantee the previous owner had maintenance being done (or did it himself) to flush the transmission fluid and they simply forgot to remove the makeshift pin. (I personally use a paperclip, which that looks similar to).

Just remove it

Yeah I did. I had a transmission shop in my area do a flush and filter change around 10k miles ago though. When I FOUND the pin it was just hanging around there and wasn’t in place. I put it in because I figured it was supposed to be there.

 

[mceagle555]

Yeah I did. I had a transmission shop in my area do a flush and filter change around 10k miles ago though. When I FOUND the pin it was just hanging around there and wasn’t in place. I put it in because I figured it was supposed to be there.

Yep...you can just remove it. Thermostat will open naturally

 

[04UZJ100]

What specifically did the shop do and how do you know they did it correctly? Transmission codes after shop work are indicative of poor quality work and or low competence.

 

[kossykoss]

What specifically did the shop do and how do you know they did it correctly? Transmission codes after shop work are indicative of poor quality work and or low competence.

The truck was around 84k on original fluid. So I had them flush all the old fluid out and refill it with amsoil atf. Also changed the filter as well. At least that’s what I paid them to do. I monitor the trans pan and torque converter temp on my ultra gauge and everything has been normal since then. The truck has 97k on it now. You think there is a potential that the shift solenoid is acting up because of crap service?

 

[daneo]

Anecdotally, Toyota transmissions have a strong preference for Toyota WS transmission fluid. I don’t have a lot to back that up besides some forum posts and YouTube mechanics, but I’d probably swap in WS fluid after throwing a code with Amsoil.

 

[04UZJ100]

The truck was around 84k on original fluid. So I had them flush all the old fluid out and refill it with amsoil atf. Also changed the filter as well. At least that’s what I paid them to do. I monitor the trans pan and torque converter temp on my ultra gauge and everything has been normal since then. The truck has 97k on it now. You think there is a potential that the shift solenoid is acting up because of crap service?

Yes.

 

[BVE]

Has the code returned? I’d highly recommend double checking the trans fluid level.

 

[kossykoss]

Has the code returned? I’d highly recommend double checking the trans fluid level.

I’m going to check this weekend. It has not returned after manually operating the solenoid. I’m already ordering new Toyota fluid to do a flush at home asap

 

[joyRidaz]

I’m going to check this weekend. It has not returned after manually operating the solenoid. I’m already ordering new Toyota fluid to do a flush at home asap

Now that it’s colder I get and clear these codes every few days, usually when im going up a slight incline at a casual speed. If I floor it to keep it at higher rpm’s for longer I can avoid it being tripped. 2008 lx 130k, did a diy full flush of WS last summer, checked the level multiple times. Head scratcher.

Very interested in any learnings from the future replies

 

[joyRidaz]

How do I manually operate the solinoid? Do I need techstream??

Now that it’s colder I get and clear these codes every few days, usually when im going up a slight incline at a casual speed. If I floor it to keep it at higher rpm’s for longer I can avoid it being tripped. 2008 lx 130k, did a diy full flush of WS last summer, checked the level multiple times. Head scratcher.

Very interested in any learnings from the future replies