I have a 1999 mountaineer with 100k on it. There should be a 5 volt ref at thte gray/red wire at the cmp sensor which comes out of pin 85 on the pcm. I have nothing there and was wondering if it is common for a wire break under the plenum or somewhere in the harness back to the pcm. Obd2 code triggered is p0340
I'm making a donation but I'd rather pay 50 bucks for the guy who finds my problem!
Its very possible for a wire to chafe or break. And bear in mind also that the 5 volt signal is provided by the pcm so. Hate to say it, have seen a few fail internally. Lets hope its just the wire! Let us know!