Need Transmission Wiring Harness and "Valve Body"

Mechanic is telling my truck needs the "Transmission Wiring Harness" and the "Valve Body". 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.

2006 Toyota Tundra DoubleCab V8 SR5 4WD 5TBDT44106S534603

 

If it’s the A750, the wiring harness is known to corrode; why’d he say you need a new valve body?

 

Joseph, are you saying that the wiring itself may solve my problem?

 

Not necessarily, what problem are you having?

maybe if all your solenoids are going crazy it might just be a wiring issue; hard to say without seeing in person, or could be a single corroded wire

 

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

My mechanic also saw the damaged wires.

 

whats the year make a model?
2006 Tundra, V6 or V8, 4wd or 2wd?

 

2006 Toyota Tundra DoubleCab V8 SR5 4WD 5TBDT44106S534603

 

DTC P0710 Transmission Fluid Temperature Sensor "A" Circuit - either the wiring/connector/or sensor is bad
DTC P0712 Transmission Fluid Temperature Sensor "A" Circuit Low Input - either the wiring/connector/or sensor is bad
DTC P0986 Shift Solenoid "E" Control Circuit High (Shift Solenoid Valve SR) - short in the wiring/shift solenoid is bad/ or ecm is bad

all three are strongly pointing to the wiring being the problem, and since we know the wiring corrodes on this tranny, thats a strong possibility. Why'd he want to replace the valve body too? (also you can ohm out the E shift solenoid to see if that is the problem if replacing the wiring harness doesn't fix it.)

 

Thanks Joseph, I get your point about going for the harness FIRST and see if that solves the codes. My mechanic thought (assumed) that the corrosion had damaged both, the harness and the valve body. Is the harness really about $650 ?

 

I see, @shifty` might be able to chime in on if the valve bodies corrode as well but my understanding it was just the harness

and no sir from a quick google search (not official parts stores) the harness is only about $150- I know the valve body is about 1k, so maybe he found you a remanned one that’s cheaper and that’s where the larger total is coming from? Did he give you an itemized quote or just the estimate over the phone?

 

My mechanic updated the heads of the harness and some of the pins on the valve side. Check engine light is gone. I'm test-driving it for a couple of days but drove it today and it felt great.

 

Did you tell him what we said here? Or did he just decide to do a proper diagnostic?

 

If the malfunction of the harness was caused by water, what is the usual solution to prevent water from damaging those again?

 

Grease your electrical connections?

 

di-electric grease.

 

Bacon grease.

 

Di-electric grease; but was it the connector inside the transmission? Or the main connector outside on the housing?