Trans or TPS ?

[LILFOOT]

09 STA 4.6 AWD

Lately i have felt a weird humming sound, almost as if my driveshaft or rear-end is starting to go.

It only happens in 6th gear, at about 60mph, with very light throttle (cruising, just to maintain speed).



When i look at the data in Torque/OBDLink, i notice that my Absolute Throttle Position is at 18% with no input and maxes out at 76% with pedal floored.

At 60mph at less than 1/4 throttle it is just above 50%.



When this 'noise' happens the Absolute Throttle Position spikes to 76%, even though i havent moved the pedal any.



RPMs do not change, so i dont believe the trans is slipping.

Trans fluid is full, even though bulkhead connector is leaking pretty good.



Wondering if anyone else has noticed anything similar ?

Or where i should start looking ?

Throttle Pedal ?

Throttle Body ?



I tried this with the stock tune and both of the tunes from Torrie, with no difference.

So, i am pretty sure it is not tune related.



I have also done the Pedal calibration multiple times and see no difference in range or position.

 

[EddieS'04]

I dont know about the gen2. The gen1 TPS at throttle rest KOEO should read .899 to .995vdc.

Full throtle 4.76 volt DC.

Link will show wires for gen1. Not sure how this will work on gen2 with throttle by wire.

 

[Vic Sorlie]

When were transfer case and differential fluids last serviced?

 

[LILFOOT]

I had a full system flush done last April.

Havent pulled the pan yet, was hoping to get it through the winter, and fix the bulkhead connector leak while in there.



FYI, it just turned 100k miles.

 

[EddieS'04]

I beleive someone reported that a dirty MAF can cause trans problems on the Gen2 Trac..

 

[ZoNiE]

If it ends up being your TPS, don't forget the cover page.

 

[LILFOOT]

Cover page ?

 

[Vic Sorlie]

Bulkhead connector...yep, had to have that one done too. I think the humming noise is driveline-related, not anything electonic. I'd start with inspecting driveshaft u-joints.

 

[ZoNiE]

Movie joke... Office Space.

 

[Vic Sorlie]

Bulkhead connector...yep, had to have that one done too. I think the humming noise is driveline-related, not anything electonic. I'd start with inspecting driveshaft u-joints.