For over a year, I was getting a P1584 (Throttle Body input circuit failure) intermittently (aren't most electronic glitches intermittent?). It would throw an Engine Failsafe Mode alert, a CEL, and stay there for about 30 seconds.

What didn't work:
Disconnecting electrical connectors, and spraying DeOxit D5 on all pins.
Spraying MAF sensor cleaner in the air-assist modules' hose connection.
(Note: only present on 1st generation models)
Sprayed Throttle Body cleaner on entire assembly.
Looked clean and new, worked like @&$/.

Time to punt. Independent shop sent the unit out for a complete rebuild. Problem was with the internal electronic module. Rebuild carries a lifetime warranty. Two months later, not a single malfunction.

Reason for this post: multiple searches revealed no root cause, and all DIY attempts to remedy were ineffective. Sometimes replacement or professional rebuild IS the only option.

 

Did you see my freshly updated post about a P1584? I installed a guaranteed used throttle body (eBay) and the fault never returned:

https://www.jaguarforums.com/forum/s...m-leak-142564/

 

Good write-up! I saw a few used ones on EBay, but at the time, the ones with identical part #s were posted "as is," and I didn't want to replace a bad throttle body with a potentially worse one. Recent Craigslist postings were for unlike engine or year. Glad you found a good used donor.

You're correct in stating the ease of actually removing the throttle body assembly, even for the 4.0 engine. Timing is everything....I needed a guaranteed fix ASAP, so I was not unhappy with the verdict. For 2017, it represented the one major repair per year most S-Type owners encounter.