Need Help with Some OBDII Codes

[AirmanSkee]

So for a while my truck has been running weird and I could tell it was trimming fuel and misfiring sometimes. Mostly when I would really get on it around 2-2500rpms. And would also hesitate sometimes when trying to shift up.

At first I thought it was from my new exhaust, having the rear O2s open, and maybe getting wet or just being bad. But those are only for monitoring, and don't control fuel trimming/timing/etc.

So then I was checking my MAF and other plugs and vacuum lines for leaks. And I found this little plug dangling by my K&N. I had seen it before but never bothered with it.

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After doing some research, I found I should have an Intake Air Temp Sensor, which I don't.

Notice below it in the pic there is a small hole behind the MAF on the K&N box? That is where it should be.

So I ran my codes again today and got this little clip.

http://youtu.be/8lHg_LKxcf4

P0113
P0712
P0113*
P0719*

It also picked up the misfire, and the Rear O2s as well.

But P0113, is the IAT sensor that I am missing. Which the IAT plays a factor in fuel/air ratios and also timing. So that is most likely the main culprit in the misfire. I will be getting one tomorrow and seeing how it goes after that.




As for the P0712, and P0719 codes, those have me stumped. As far as I know, we do not have a Trans Fluid Temp sensor on our 4L60e from stock do we? The P0712 code is saying that my TFT sensor is malfunctioning, but I can not find a definite fix or part to replace for that.

And for the P0719 code, I am unsure the fix for that as well. It says Torque Converter/Brake Switch. I have my ABS fuse pulled, and maybe that is throwing that code?


I erased all the codes today and drove it around. I will re run the codes tomorrow and see what shows up.


Any help would be greatly appreciated!

 

[someotherguy]

There is indeed a temperature sensor inside your 4L60E. It's not there to drive a gauge in the cluster like on some newer trucks, but there as an input to the PCM.

Haven't yet heard of one going bad, so maybe you've got a wiring issue, or damage at the connector to the trans - maybe the harness is leaking fluid? Or could be a bogus code.

And yes, you definitely need the IAT.

For the P0719 check your brake light switch that hangs off the pedal. These go bad pretty easily and your brake lights can still work. There are multiple sets of contacts in there. The switch is cheap. A little bit of a PITA to replace just because the clip is weird and it's in a tight spot, but not a tough job. Spin the clip around so that you can see the split in it, where there are two little half-circle holes, you can gently spread those apart with snap ring pliers and slide it right off the stud so it can be re-used.

Richard