[mgblack75]

I have a 2006 4 door Tundra XSP with the A750E transmission. Yesterday on my way to work the check engine light came on, after sitting all day the light was off on my return trip home, approx. 11 miles. When I got home as I pulled in the light came back on and the transmission did the jump scenario that I have seen mentioned as if someone had just rear ended you.

On my way to work today it began to slip and then reengage rather violently a few times. After connecting a scan tool to it we found the code P0986 Shift Solenoid "E" Control Circuit High. Checked and cleaned the 15 pin connector and checked resistance of the solenoid. 1st check revealed an infinity to ground. Checked later and the circuit was within the 11- 15 ohm range. Also checked the circuit from the ECM to the female 15 pin connector and the continuity was good.

I decided to take it for a quick test drive and it resulted in the transmission slipping and reengaging harshly over and over again. I am Soldier stationed in Germany with no access to anyone who knows anything about a Toyota Truck. From what I have read the ECM should take over and turn off the SR solenoid to allow for continued safe operation, but I am not experiencing that. Can anyone provide any assistance at all? I would greatly appreciate any help or advice. This is my daily driver and I have no other way of getting to and from.

 

[David Jones]

I have no idea but a Google turned these ideas up......
Auto Trans Issue P0986 - Toyota Nation Forum : Toyota Car and Truck Forums
http://highlanderclub.ru/files/manual/04/21acxt2c/cip0985.pdf

 

[mgblack75]

Thanks for the reply. I am using the troubleshooting procedure that was in the second link, but I keep getting different reasons. There was some good info in the first link too. Again, thanks so much for links.

Anyone else experienced this fault yet?

 

[bgeorge]

I had the same problem and Toyota told me I needed a new tranny. I brought it to my local transmission guy and searched the internet. On my 2005 there is a 15 pin connector which connects the tranny to the computer.
Two of the pins were corroded and broken off inside. I posted all this a few years ago. Do a search for 2005 tundra transmission.

 

[mgblack75]

bgeorge,

Thanks, I read your post earlier yesterday. We pulled the 15 pin off and there was minimal corrosion, all pins were there. We cleaned everything and coated with dielectric grease. Thanks for the reply.

 

[mgblack75]

Did some more testing today and all of the solenoids in the transmission are showing the proper readings. Also rechecked the 15 pin connector, everything is clean and in place. Also, did the Toyota manual shift test with trans. disconnected. Truck drove fine and manually shifted, which tells me it is an electrical fault. I was leaning towards the ECU until I found 7 - 8 ohms of continuity between sockets 7 and 8 at the 15 pin connector. According to the Toyota wiring diagram there should be no type on continuity between those two. One pin controls the SR solenoid and the other controls the S1 solenoid.

Can anyone tell me if there is a wiring harness junction anywhere between the 15 pin transmission connector and the ECU where I could try to narrow down which part of the cable could be faulty?

 

[mgblack75]

*Bump*

Is there anyone out there that knows if the harness at the transmission is one complete harness with the engine harness, or is there a Junction somewhere in it where it can be separated?

Thanks for the help guys, I am in a jam over here in Germany.

 

[2003bajatundra4x4ac]

i'm no help, but it is a long weekend over here. give it some more time.

oh, and we appreciate you being over there!

 

[mgblack75]

Thanks, I almost forgot it is a long weekend for you guys.

 

[Remmy700P]

I wish you the best of luck. When you start to narrow these issues down to a harness, it gets real lhard to offer further online help. These can be a cast-iron b***h to nail down.

 

[BDeppe]

I had the identical problem and wanted to provide the Toyota Parts numbers for ease of repair. (2006 Toyota Tundra DC 4wd SR5 4.7L)

Internal Transmission Wiring Harness- Part # 82125-60650 List price $60.80 Dealer Cost 42.03
External Housing to ECU side- Part # 9098012293 List $12.04
External Pins to be soldered and connnected back into ECU -Part # 8299824250 List price $17.27 Each 15 Pins total if all need to be replaced.

With the help of this forum along with some additional research on the internet we were able to narrow down the problem. Same symptoms as discuss in prior forums. Vehicle shifting hard (especially in wet weather and salty roads), eventual failure with trans slamming into gear, almost undriveable and engine code of P0986. When disconnecting Internal Harness which comes out of actual trans housing, pins were found to be broken and/or corroded on both sides. Replacement of harness inside transmission (required dropping of trans pan and valve body), harness connector outside and replacement of corroded pins to ECU fixed problem. With labor from private mechanic total bill of about $750. The problem took a while to diagnose and he had some time in it with wiring, searching for solutions etc. Again, as posted in all other threads, Toyota wanted replace trans which is curious as this would have only solved the problem on the trans side not the ECU main harness side.

Hope this helps those who experience similar problems.

 

[snipefarmer]

Similar symptoms on my '05 Tundra - not shifting into 2nd, poping out of gear at highway speeds. The dealer diagnosed a faulty sensor cable and wants $500 to fix. I thought this was steep until I read the previous post.

 

[zxylene]

I was reading this and I think I have the same problem with 2005 Tundra the wiring harness. I wanted to see if it is corroded where it connects to tranny but I dont know how to separate them. Anyone have a picture of the harness connector and how to get them apart. I want to at least put dielectric grease in them to keep this from happening but I also dont want to break them taking them apart . I cleared my code p0986 I dont want it to come back or add more because I screwed up the connector or wires. I was also wondering if it is damaged or pulls out the male ends can I replace them or swap them out without taking the tranny apart.

Thanks for any help. I want to save money and do the work myself.
Bill

 

[Lucas Porter]

Does anyone have a part number for the external harness?...Mines in rough shape and thinking on just replacing it

 

[Daniel 23]

I’m hooking up a trans temp gauge in a 2006 Toyota Tundra 4.7 need to know we’re to hook the temp sensor for the gauge up or do I use trans pressure port and we’re is that at

 

[Daniel 23]

I’m hooking up a trans temp gauge in a 2006 Toyota Tundra 4.7 need to know we’re to hook the temp sensor for the gauge up or do I use trans pressure port and we’re is that at