85GT-79FJ40

I have an 05 double cab 4x4 V6/auto with 140k on it but I stopped driving it regularly in April when I got my summer driver out of storage. Going to the dump one day the check engine light came on. As usual it drove fine but I checked the code when I got home. It was a generic transmission shift solenoid code. I cleared it and all was fine the next time I drove it around town. But the next week the light came on again and it started shifting really hard. The code came up P2716 which is a shift solenoid D which is the line pressure solenoid for the transmission. I tested the ECU end of the harness according to the FSM and the solenoid tests OK between it's two leads. Yet the readings checking each to ground are kind of inconclusive. It's supposed to be more than 10 K Ohms and both are. But on another test I found for the same transmission in a tundra there isn't supposed to any continuity at all. Anyhow I can't get the code to clear. With the ignition on it's always there. I've disconnected the battery and touched the terminals together, I've tried clearing it with my code reader a dozen times and nothing makes it clear. This same code was really common for ECU failures in other Toyota's and I'm thinking it may actually be the case here too. Any thoughts? Anyone know if later ECU's like this are coded to the vehicle? Would be nice if I could just install a used one.

85GT-79FJ40

Although this didn't generate any replies the truck is now fixed and it's not what I thought it was. But the solution is kind of a public service announcement for anyone with 03-up tundra, 4runner, or 05-up tacoma with a 5 speed automatic. There is a plug on the side of the transmission for the valve body solenoids. It's a female plug that faces upwards (great idea Toyota) so it can hold water. Here in New England they use a whole lot of road salt so the result of 7 years of this treatment was a plug that had 6 pins in it that were green with corrosion. It was quite difficult to unplug it but that's because when I unplugged it I actually broke 2 of the pins right out of the female side! It's not easy to get to even with the driveshaft out and I was becoming increasingly more frustrated trying to work on it so I brought it to a shop a friend manages. Toyota sells a repair kit for the female side of the plug which is actually the entire valve body wire harness. The male side they don't sell though. Not even replacement pins. They expect you to purchase an entire transmission wire harness. The shop got a plug off a salvage 35k mile transmission and used it for the 6 pins I needed and kept the rest for the next one they have to fix... And when they were done they packed both sides of the male plug and female side with dielectric grease. So if you have one of these transmissions pack that plug with dielectric grease before it gets corroded and causes you all kinds of headaches. I so wish I had been able to find this exact same truck with a manual transmission used.

vital22re

iTrader: (2)

I changed your thread title to help anyone who's having similar issues find it easier. Thanks for posting the info.

Ringmaster

Thanks for the info on Dielectic silicone.

Up here in the frozen north they use liquid de-icer, which finds it's way into everything electrical.

Anything I can do to stop it's advance is greatly appreciated.