I am the delegated repairer for the daughter and son-in-law's Neon. I am old enough to have been retired from auto repair for...a while now.
Please bear with me.

P0715 code, input sensor. Happened before...several times. Warranty at dealer took care of most, but now out of warranty.
It is not the sensor.
I obtained a printout of wiring for the sensor, pin 34 is where I need to check continuity for signal to sensor, it looks like. Some forum I read several days ago stated voltage at the plug to the sensor needs to be 12V, poster had 4, cleaned connectors all was well.
Airbox out, key on, .25V between pins, and signal to body ground. Doesn't look right.
I know from folks I've talked to these have issues with computers, PCM and TCM, needs flashing at the dealer.
Steer me in the right direction on troubleshooting and electrical problem isolation.
Son-in-law has been out of work since Thanksgiving, so it's me doing it.
Thanks.
Dave

 

Arrgghh. So, tore it apart, pulled the plug on the input sensor and c-4 on the PCM.....and no continuity for signal line. Had it for ground.
Cut open the harness....the plug is spliced in about six inched into the harness. No idea if factory or not.
Harness rubbed in places, some wires a little "flat", no rubber bands (pull, if it stretches like a rubber band, conductor is broken).
No corrosion anywhere. Plugged it all back together, assembled the air box...and it's fine.
I hate these problems.
I did electronics, military, industry, then automotive, did computers from the first (what, 1980 General Misunderstanding?) and why do we need all this on the transmissions.
I remember Caravans....$4800 to rebuild one with all the electronics...and the junkyards were row upon row of perfect T&C, Voyagers, caravans, interiors perfect, paint, glass, no damage...engines were fine...transmissions were shot, every one.
Neons really have this much sensor and transmission computer issues?
Thanks.
Dave