Adam F

Now, I've been driving a 3rd gen 4Runner now for 10 years. I know how the 2nd to 3rd shift is supposed to work. Temps below 40 degrees or so, the ECU makes the 2nd to 3rd shift point right around 2750 until a certain temperature is reached, to help warm the engine up faster.

Problem is, my truck now does this 100% of the time, no matter the temperature. Its close to 90 degrees and its doing it.

So what exactly tells the computer when to make this shift point? ECT sensor? Temp sensor in the trans?

I have a bluetooth scanner on my android phone, and I can monitor the coolant temperature, and its reading perfectly normal, starts out and ambient temperature, and goes up to full temp, smoothly.

Now, isn't there 2 temp sensors, one that gives the dash gauge readings, (is this the one I'm reading using ODBII?) and then one that tells the ECU the temperature?


I'm assuming that the ECU sensor is up front under the fuel rail? If so, anyone got a part number for this? Parts store can only find one temp sender, not sure which one it is.

Thanks. 3.4L. Getting lousy fuel mileage, about 13 around town, 15 hwy. I used to get 17-18 city and 20-21 highway not that long ago. I replaced the upstream o2 sensor a while back with little change.

Adam F

Nobody?