Originally Posted by 2005JGC
It rarely fails in any way other than a wondering idle maybe some harsh shifting from the trans. Its not important enough of a part (something that will leave you stranded) so ultimately its not really worth carrying a spair.
Actually, its failure was first brought to my attention by the torque converter locking and unlocking as we drove at 75mph. After about 10 miles of this, the transmission started downshifting and upshifting, downshifting and upshifting, while traveling at a steady 75mph. Also, the air conditioning compressor would cycle on and off every one to two seconds (noticeable while idling). Both my Jeeps exhibited these same issues, caused by the failure of the TPS. Granted my own GC had the wandering idle as well, but the wife's did not.
None of this was good for the components, so I replaced it as soon as I got to the next Jeep dealer.
Thanks for the thoughts, I'll keep a new TPS in with the spare tire.