A750F / A750E P2716 wiring harness short FIXED!

Thanks. I was a bit nervous at first, but there was no looking back after the first cut, and just pushed on because I knew 1 of 2 things would happen. It would either work as planned, or it wouldn't work and I'd be asking my wife for a ride to work with my truck unable to move if I screwed it up.

 

Not sure if you had the battery disconnected , but now that the code is cleared , enjoy the smooth shifts . Its going to be a different truck

 

I ordered up 2 more plugs for spares. I'll build up a couple more.

 

Good to hear you solved the problem. I ended up bringing mine to a reputable transmission shop who confirmed what I expected...the female portion of my plug had a pin break off. That being said the internal harness has to be replaced. I suppose I could just rewire the one pin but might as well do it right and replace whole thing.
Also considering having the shop do it, the bolt which holds the plug on the transmission is rusted and pretty seized I was having trouble getting a grip on it.

 

That sucks. I replaced my internal harness not too long ago. It wasn't too hard, but I had to move quick which wasn't easy laying on the ground under the truck with atf dripping all over me. It seemed like it would never stop coming out when I removed the temp sensors. I probably would pay not to have to do that again. Or change the plan of attack to make it a bit easier and cleaner.

 

That’s what I figured too I was under there swapping the solenoid out and it’s just a mess and end up pretty sore and banged up afterwards. He said it would run me about 250 for the parts and new fluid including 2.5 hours billed labor. I think it’s fair for what’s involved, would I like to save the money and do it myself sure. If only I had a lift! Plus I know exactly what needs to be done as does he so I’m not getting taken for a ride.

 

Did you have to pull the pan to replace the internal harness?

 

Yes. A few other misc brackets and the filter/strainer also.

 

This is really helpful, I am about to do this fix myself. Have a question, if you can still remember, can you walk me through how you fished the wiring harness up to the engin bay? What other connections did you have to disconnect to make that happen?

 

So if you goto each side of the transmission, you'll find where the harness plugs goto the PRNDL selector, the solonoid plug, and also the catalytic converter sensor plugs. Unclip those, and also follow all the way back to the transfer case, if 4wd, and you'll need to unclip the transfer case plugs. It's a bit of a pita, but along the top of of the transmission, spine I'd call it, there's the little plastic clips that hold the harness in place. Those are there all the way up to the bell housing and back of the engine heads. You'll literally have about 6ft of harness that will come out, but you only need one plug that is among about 20 others wrapped up in that section of harness.

 

Lets just say my cables and connectors are fine and I wouldn't mind just dropping my transmission pan to change the solenoid for the hell of it. Which one would be the 'D' solenoid? and were would that be located on the valve body? I wouldn't mind just changing it before I take it in for the big dollar job at a shop.

 

https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

Glad to see you're still around @gearcruncher

 

Hey Bob!! I'm glad your still around!! I really liked your thread. I am having the same issue, and this thread you started is my guide. I haven't found my issue yet but I'm still chugging along. I guess what you did solved your problem?

 

Holy smokes I haven’t really been around much but have been trying to be a bit more active come the new year, so sorry for the delayed response. Hopefully you’ve been able to fix whatever problem you may have been experiencing before now.

Yes, since repairing the burnt and corroded wires at my transmission plug, this did fix the DTC reported by my ECU and still to this day, no sign of it returning or pending. If you have an error reported by the ECU that’s specific to the transmission operation the first place you should investigate is the wiring harness plug on the side of the transmission to make sure A: it’s properly latched, and B: there’s no corrosion or burnt up pins on both sides of the plug. Most of the time one if not both of those scenarios will be where the problem lies and it’s not an actual component defect. The plug not being properly latched can allow moisture to bypass the plug seal and very quickly lead to corrosion causing the ECU to report sporadic DTC’s that come and go appearing to “fix themselves”. If the ECU can’t communicate with a specific component then logically it’s going to report a problem.

If you can eliminate those scenarios by confirming the wiring and any connections along the way are properly insulated and completely latched together then the next place to troubleshoot would be the specific component that your trouble code relates to whether it be a shift solenoid, temp sensor, or PRNL sensor etc….