Transmission not engaging

I have a 2005 Tundra limited V8 2wd, I am having a hard time finding a 15 pin Auto Transmission wiring harness. I have seen here on the forum that other people have had this problem with corroding within the pins causing the computer to signal the transmission. The check engine light comes on, depending if your in 1st gear it clunks along until it engages or your driving along the check engine light comes on, then it isn't engaged the RPMs just go up but the truck doesn't engage. I appreciate any input.

 

According to the Field Service Manual (Section DI-398 / page 668), your problem lies in the ECM. Now, is the ECM bad or do you have a broken pin or wire between the trans and module? I can't tell you. How are you at checking harness pins and circuit continuity? If you are able to diag that, you can use the FSE to confirm or eliminate a wiring issue.

If you haven't, check out the MEGA THREAD that addresses just about any question you may have or any issue that may arise with your truck.

Here are a few excerpts:

Occasionally, water leaks can send water down into the ECM behind the glovebox (pics), or into the fusebox inside the cab/dash (pics & pics & pics, it happens a LOT). Many drain/vampire issues trace back to aftermarket add-ons whether the owner knows they exist or not - alarms as mentioned earlier, brake controllers, poorly installed trailer receptacles, those are some big ones.

RODENTS: Lots of plastics, wire sheaths, etc. in these trucks use soy-based plastics. If you have rodents nearby, or you park outdoors regularly, it's not uncommon for them to crawl in the opening under the intake manifold, where the starter & knock sensors live, and chew up the wiring (no start, knock sensor circuit codes). Likewise, they love nesting on top of the gas tank, and they'll chew up both the wiring like this, killing the pump (no start), and chewing up the tank tubes/plastics like this (EVAP codes, EVAP small leak, EVAP large leak). They'll chew through the gas filler neck, which will also throw EVAP codes, like this. It's common enough we can share exact photos of it, and there are more where those came from.

Also, here is a copy of your wiring diagram:
2005 Tundra EWD - EWD611U

• Includes all sections in the original book
• 705 pages

 

Thank you for the information you provided. I don't have access to any of the troubleshooting you provided. I had the truck at a transmission shop, they found 2 codes. P0771= Solenoid E which was replaced twice. P0986= not sure what this means. Someone on this forum had the same code and replaced the 15 pin male connector that was corroded from moisture which fixed his problem. It could be the EMC (motherboard). I did notice some sort of liquid (orange color) that had dripped down (wasn't very much) inside from under the dashboard between center and left side of passenger seat about 7 yrs ago. The engine light comes on then goes off. The transmission shop had it for three days light was on when took it in, he was able to get the codes. The light went off and they couldn't get another reading, I live in a very rural mountain community, so resources are limited here. Nearest city is 50 miles away, last time I drove to town, the light came on while doing 60 mph, lost transmission connection, push the gas rpms just goes up. Once the trans connected i was able to continue driving (it was scary, no place to pull over) the light stayed on but was able to get back home without any problems. As of now the light is off. I'm finding that these shops are bouncing me back and forth with it's a trans problem we don't work on trans, or its electrical we don't do electrical. One shop said if I can get the part they will replace them. Honestly it is frustrating.

 

Since you have a 2005, it will require you or someone to crawl underneath and check your transmission level since that is just one of the causes associated for a P0986.

 

thank you, I was just reading about the TCM control switch possibly being bad. The solenoid E was replaced twice, most recent 2 months ago. The one replaced was still good.

 

We also have @FiatRunner who has been suffering through solenoid E issues, IIRC.

 

The TCM they are referring to in actuality is what Toyota calls our ECM or ECU and they both are one in the same, Engine Control module or unit.

As @The Black Mamba mentioned, focusing on the ECM and/or the circuitry from transmission to the ECM is where problem possibly lies.

Are you the one attempting to troubleshoot the problem and if so in case requires chasing wires, are you equipped to do so ?

 

https://www.tundras.com/threads/wha...-gen-tundra-today.2558/page-2301#post-3877573

 

Please, Don't confuse me. I really don't know what i am doing. My understanding is: I have 2 code errors, P0771 = Solenoid E, P0986 = Solenoid E/ TMC, Transmission Control Module. I was under the impression that ECM/ECU = Engine Control Unit. I'm trying to understand so I know who to take it to. The transmission shop just replaced the Solenoid E, that wasn't the problem. It would make sense to replace the TMC since that module was also attached to the same error code. Transmission shop is saying that it's electrical. Electrical shop is saying it's inside the Transmission. I really am trying to avoid the Toyota shop.

 

Whatever happened to this? Did you solve the problem? I'm going through the same code errors myself.

 

https://www.tundras.com/threads/2000-limited-trd-refresh-repair-story.116395/page-17#post-3909319

 

hmmmmm. I would probably start with this. Water intrusion from leaking cowl clips is a common problem. The computers that live in the passenger kick panel are affected by this.

 

My mechanic is telling me that the harness that connects to the TCM is fried and needs to be replaced. He is trying to find a used one, instead of buying a new harness from Toyota for almost a thousand bucks (according to him)

 

Fried how? Melted? Or severely corroded? Maybe a JY part will do?

 

Mechanic is telling my truck needs the "Transmission Wiring Harness" and the "Valve Body". He is not finding these and has explained to me that these two parts are usually sold together with a used transmission. I'm debating whether to wait for these two parts to become available or to buy a used transmission with those parts in it and replace the whole thing. I'd prefer NOT to replace transmission if I don't need to. For a little reference, I bought the truck from its original owner with 254K miles. It now has 259K. Aside from a little rust in the frame, the truck is in excellent overall condition.

 

What is your casting ID number? I have a used one at the house #8931

 

2006 Toyota Tundra DoubleCab V8 SR5 4WD 5TBDT44106S534603

This is me.

 

No, not VIN number. Casting ID number on the valve body. Never mind, we have different valve bodies because we have different transmissions. Sorry. My eyesight gets bad later in the day and 6s start to look like 0s.

 

Could be the HEAT down there... you know, like a mirage. just sayin

 

Judging from the Yankees posting in the lunch table, it's cooler in Texas

 

I looked at the temps then, and you were correct. I was surprised, Big surprise... but we can compare again in late July

 

Your problem lies in the ECM.

 

Backroagee, please be more descriptive. What exactly do I tell my mechanic?

 

Actually, no one on here can give you any useful information other than what you supplied to us stating that Mechanic is telling my truck needs the "Transmission Wiring Harness" and the "Valve Body". What exactly are you experiencing? You didn't ever tell us (at least in this thread) what the actual code was. Also, you haven't told us how your mechanic came to his diagnosis. For any of us to actually be of help, we need to know all of the info.

Also, @Backroadgee could have been replying to OPs 1st post. If that is the case, I agree (see my 2nd reply).

 

Thank you BlackMamba. I have codes P0710, P0712 and P0986. Truck even went on Limp mode.

My mechanic also saw the damaged wires.

 

So I will agree that the harness MUST be replaced. I'm on the fence about the VB as he couldn't properly test that in its current condition. While some harnesses may be spliced into, others cannot due to a change in voltage and resistance. I'd go to a JY and find a 05-06 V8 and take that harness. The V6 might also have the A750, but I don't know for sure. I do know that the drivetrain doesn't matter as the harness is the same. Plug in that harness, clear codes, reset throttle body and test.

 

How much is that harness new? Or from Toyota?

I ask because he has not been able to find it at junkyards.

I don’t want to wait a lifetime and may just buy it new so I could use my truck again. At the shop for two weeks now…..

 

Search the EPC to find the part number. THIS POST will help you do that.

 

Teach a man to fish, and he'll never go w/o the right part (hungry)