2012 Tundra question regarding throttle position sensor #2

Hello, I just aquired a 2012 Tundra 4.6 liter. It has been throwing the lean codes for both banks, P0171 and P0174. I have a descent scan tool, and I believe the Throttle position sensor is bad, I'm not sure, but when I graph it, it is not steady even with a steady foot on the pedal. My scanner also lists a PID for Throttle position sensor 2, and it reads in % I think. It does move a little, but it is basically stuck at 47%. Also my inlet air temp sensor doesn't move much. Its stuck around 40C, (104F). I looked at it today, and its about 62F outside, I don't think the air would warm up that much.

So my question is, where is the throttle position 2 sensor located? I'm guessing its integrated into the throttle position sensor, since there are 6 wires coming out of it. Also, where is the IAT sensor located? is it part of the MAF?

My long term fuel trims are hovering around +20, so something is going on, My A/F sensors appear to be operating fine (they graph like they are supposed to on a snap throttle). Has anyone had an issue with their throttle position sensor? There's basically nothing on youtube about it, so that kind of says its not a major problem on these trucks.

Thanks,

Dave

 

You can try cleaning the MAF with MAF approved sensor cleaner. But its not normal for it to be stuck like that. If you end up replacing it, buy Denso quality. Cheaping out on critical components has shown to not go well.

You might also look for mouse droppings. Those guys can wreck stuff.

 

As for the TPS, try disconnecting it and verify connection is clean and free of corrosion but ya, it's all integrated.

 

Thanks all,

I did unplug and replug the TPS, and it seems to have had an effect. I'm going to do a more detailed inspection of it later today. Also, it looks like the TPS is integrated into the throttle body, so if you do have a bad TPS, you need to do the whole throttle body. I'm also going to test my IAT sensor by removing the air filter and replacing it (temporarily with some screen with ice cubes on it. If the IAT doesn't move off of 40C then, I know its bad.

Dave

 

IAT is read from the MAF sensor. TPS like you said is integrated into the throttle body. You could try cleaning both the MAF and the throttle body with their respective specific cleaners intended for each. The throttle body make sure you don’t use anything abrasive on it and don’t push on/actuate the throttle blade manually. Just clean it as best as you can in the closed position with the truck/power off. If your TPS isn’t matching the command it could be getting stuck if the TB is gummed up. A dirty MAF could also explain erratic fuel trims.

 

Thanks again,

I did remove and look at my throttle body and the side facing the airbox was pretty clean, but the side facing the intake manifold was pretty dirty. I cleaned it up and also looked at the connections to the MAF and TPS which looked OK, but I did make sure they were well seated. I did some more scantool testing, and the TPS is still sometimes erratic in the graph. Since it is fly by wire, I may also suspect the accelerator position sensor. I'm going to give that a closer look later today. I did notice one thing, the TPS % reads 0% when I'm not touching the gas pedal, but the accel position reads 16% at a minimum. I did look a little on youtube, and I see that these sensors do go bad. One of the things I've definitely noticed since getting the truck is a touchy throttle and jerky shifting.

Dave

 

Hi Dave . I have tha same issue with my truck. Did you find out what was the problem with your truck?

 

The plastic side cover on the throttle body is essentially unsealed… despite having a groove around the perimeter of the cover, no o-ring type seal is present. Over time, contaminants can gain access and foul things… not always the issue, but it happens.

They are easy to open up, drill out the six rivets and the cover pops right off. It can be riveted back on, or tap the old rivet holes for M5x1.0. 10mm length bolts are perfect. I have the o-ring dimension somewhere.

 

Thank you for taking the time to respond to me. Have nice thanksgiving God bless You.