P0770 - solenoid E code

Hi all,

Got a question for you knowledgeable folks. My check engine light came on today.

The code was for P0770 - solenoid E error. In my truck, the shift from first to second can be jolty if I press on the gas somewhat heavy, but it’s not terrible. I took it to a shop today and they said they can replace the solenoid but there could also be larger transmission issues at play that could require a full replacement (hopefully not the case). This was not a transmission specialist and I do plan on taking it to a transmission shop to get another opinion as well.

Has anyone dealt with this code before and if so, what was your approach to fixing the problem? I'm guessing the first step would be to replace the impacted solenoid(s) but wanted to reach out here first before doing anything.

Thanks everyone

 

First, stupid "sorry but gotta ask" question, have you confirmed your transmission fluid levels, with the understanding hot and cold levels are expected to be read differently? Symptoms and code related can be explained/caused by both.

Also, have you checked your fluid to make sure it's still pink, not frothy?

Clunky/late shift from 1->2 and 2->3 is a common report in these trucks with AT when cold.

 

Oh @Tundra2 didn't you have this code BITD?

 

Thanks for the reply @shifty`. Yes the transmission fluid is good and full. I had the fluid replaced when I purchased the truck a few months back and checked the levels myself after when the vehicle was warmed up.

 

Ok, over-full, under-full could both cause shift problems. And the transmission line runs thru the radiator, and the seals break down over time, and can cause coolant to contaminate your fluid ("pink milkshake").

I know P0770 can be as simple as replacing the solenoid itself., but IIRC, it can indicate a problem with your torque converter.

 

Yes, silver truck still has it. Never fixed it. Never caused shifting issues for us. YMMV

 

Got it, thank you both for the input. I'll see what my transmission shop says and then go from there. Will provide an update in the thread if there is anything to report.

 

1. Is it slipping or shifting poorly?
2. Is ATF look red and clean or black and burnt?
3. Does ATF appear milky (emulsion with antifreeze)?
4. Is ATF Dex3 and correct level?
5. Can you clear the code?
6. If none of these could be a bad solenoid. There are 3 in the transmission. Not a difficult job but beware of aftermarket electrical items. Use only AISIN, Denso or OEM

 

@bfunke thanks for the info!

1 - No slipping. From first to second, the shift can be sort of jolty but not too bad.
2 - The ATF looks clean and red. No black
3 - The ATF does not look milky. It looks pretty clean, clear, and red
4 - I will confirm this with my shop who did the ATF fluid a few months back. My guess is that it is Dex3 since they work on a lot of Toyotas, but something I will definitely inquire about
5 - I just cleared the code and the check engine light went off. I'll monitor to see if it comes back on. Hoepfully it stays off haha
6 - Appreciate it! I'll proceed accordingly if the light comes back on...

Thanks again!

 

@bfunke do you have that compatibility chart you shared with me? That may be really helpful; it's totally possible they put the wrong fluid in it. I was shocked to see some earlier trucks take DexIII instead of T-IV or WS.

 

I realize this isn't the same situation, but I had issues with the solenoids in my transmission too.

I had a P1760 code, which is "Shift solenoid SLT circuit open", or "Shift solenoid SLT error". This solenoid controls the smoothness of the shifts when upshifting. It would slam into gear and chirp the tires. Twice my very reputable transmission shop replaced the solenoid and internal wiring harness, but the cause was actually an intermittent short on the external harness. Whatever, that doesn't apply to you, but here's what does:

The solenoids should be able to be replaced easily, without the transmission removed, and if the issue is a break or short in one of the wires, internal or external, it should be fairly easy and straightforward to replace, at least for a transmission mechanic. I'm not experienced with automatic transmissions, but it sounds to me like it could be a similar issue to mine.

I'd take it to a transmission-specific mechanic.

 

Common issue, my truck does it too. Read here

 

Expand on this "vibrating when braking and turning", since that sticks out to me here.

Like ... Explain the type of turns, at slower speed or any speed? While accelerating from a stop, while braking at low speed? Also, explain the "vibrating", like ... Do your RPMs change? Do you feel it in the seat, in the steering wheel, in the pedal? Is there a sound with the vibration?

Also, what do you mean "almost turns off/loses power"? Like ... all the lights dim and the RPMs drop significantly or something?

 

Hey Shifty, thanks for the reply!

I feel the vibration in the steering wheel mainly. This happens when accelerating in first gear and getting close to shifting to second, shortly before the jolt I feel when the truck officially does shift to second gear. The vibration is also apparent when breaking once the the truck reaches similar speeds. I also feel the vibration in the steering wheel when going in slow speeds and taking a sharp turn. The RPMs don't change with the vibrating.

That's exactly it. When shifting from reverse to drive, the lights dim and the RPMs drop significantly, almost to 0 before jumping back up.

 

Did the shop have any commentary about the torque converter?

I'm just trying to visualize here those two specific symptoms (electrical power loss, shuddering at the steering wheel), and what would cause both in tandem with throwing solenoid codes (i.e. fluid movement issues).

I'd be curious to hear what they'd say if you asked about it. Cheaper than a trans rebuild, but if bad, can result in needing a rebuild.

 

They 100% did. They initially said that if the solenoid replacement doesn't work than we'd be like at a new torque converter. They then said that there is no guarantee the torque converter would solve the issue and a rebuild might be a better option - but that's obviously 3 times the price, so it's a tough one..

 

Ok, so I'm not crazy.

Not a transmission guy, never claimed to be on this forum, but I tend to agree with them. i.e. I don't think theyr'e blowing smoke up your ass. And if the TC is failing, utimately it can take your trans with it.

I'm a gambling man. I'd be tempted to throw a new (edit: or good used) TC at it, see if it fixes the issues. The downside/risk is, if that's not the issue, you've also got a rebuild in your future. Upside is, if that's actually the issue, maybe you caught it early enough a rebuild won't be necessary.

 

Makes sense - thanks again! I'll let you know how things go.