2007 xlt drivetrain malfunction light help???

[bobditts]

2007 xlt 4.0. As you can see in the picture, my "wrench" light (drivetrain malfunction indicator) has illuminated.

Here are the specifics...

- Only triggers illumination at 65mph or above. Stays off during city driving.
- Does not matter if cruise control is used or not
- Stays illuminated once triggered until the vehicle is turned off.
- Does not throw any codes when illuminated
- Check engine light has not been triggered.
- Vehicle still drives normal. Occasionally it will have a shutter or rough idle while the light is illuminated.

Troubleshooting steps already performed...

- Visual vacuum lines inspection
- cleaned MAF and throttle body
- Visual engine bay inspection. No obvious signs of trouble.

My thought is that it is related to the throttle position sensor. But I am not a mechanic so I want to hear your ideas. Thanks!

 

[bobditts]

No thoughts huh?

I forgot to mention that I did replace the big vacuum line that attaches to the top of the intake manifold and goes to a contraption near the drivers side fender well. I also had to repair the wiring that connects to the TPS as it was touching hot metal and was burning through the shielding. Neither of these repairs fixed the problem.

 

[bobditts]

*Update*

I swapped out the throttle body, the throttle position sensor, and the throttle motor with brand new parts. The wrench still illuminates at mph or above. Anything else I should be looking at or just call it quits and go to the stealership for diagnostics?