2004 5.4. A cppl moths ago while driving under normal conditions my truck went into "failsafe mode" and started running really bad. I pulled off the road and restarted the truck and it has been fine ever since.(with the exception that cruise control has not worked consistently) The last 3 days it has now done this 4 times but it never showed any codes until today when it happed and I got p2106 and p2135 I googled this and also searched this forum and it seems like some sort of sensor... when I went to auto zone to buy a new sensor they told me that the sensor is not the problem and I need to take the truck to Ford?? Has anyone had both of these codes show up together and if so do you know what part I need to replace? I am not very confident that the guy at Auto Zone knew exactly what he was talking about.

 

It could be your throttle body or your accelerator pedal position sensor.
http://www.ford-trucks.com/tsb/fullt...hp?tsb=05-14-4

 

I had a similiar issue but cant remember the codes. I replaced the TPS but it did not help, I ended up having to replace the throttle body assembly because it has something to do with the electric motor causing the issues.