CEL Code P0850 - Neutral Switch Input
 

So I've been getting this CEL on and off for a while now. This problem gives me irratic idling during warm up. RPMs start off at 2000, drops to ~1200, goes back up to 2000 in a continuous loop until car gets warmer. If you hold the clutch though, the car behaves as it should and idles properly (RPM drops from 2000 as engine gets warmer). Once the car is warm, it idles at 1200 RPM unless I hold on the clutch where it will drop to its 'normal' idle at ~900RPM.

After a search here, the problem lies from the Neutral Switch and after a clean with Contact Cleaner, the problem still persists. I might give it another try and give it a thorough clean with Q-tips. Maybe take out the voltmeter to test the connections.

Has anyone here have this CEL come up before and how did you fix it? What does a replacement switch look like?

A while back, I sprayed my clutch pedal with WD40 to eliminate the pedal squeak. Could this be a factor contributing to my problem?

I believe you just need to replace it. The pedal has nothing to do with it.

Quick question, if you've cleaned it why do you ask what it looks like?

the neutral switch is physically on the transmission.

Yep, I believe it will be the white switch/plug

I've been told that WD40 can eat through plastic so I was wondering maybe it could have eaten through the neutral switch on the clutch pedal. I did afterall, spray craploads to get rid of the clutch squeak.

I ask what the switch looks like as I am unaware what the entire unit/harness looks like. Without dropping the gear box, all I could [barely] see were the two white and two black connectors.

the switch rarely goes bad, but it's really just an on/off switch, so if it goes bad, only way to fix is to replace it.

it sits almost on top of tranny, it's at a bitch ass location. but it's doable.

Wd40 doesn't do shit. u gonna throw the switch out anyway so just put a bit of PB on it, wait couple of hours, wipe the thing clean with a towel, and try to remove it.

the threads you supposedly did all your homework in have all the answers, it has been discussed numerous times including how to get at and replace it.

been using WD40 forever, never had any issues with plastic. Best case is to blast it out with brake cleaner. The pedal switch has nothing to do with the code.

wd40 works on my bike, just not my car :(

unlike PB, which REALLY DOES eat plastic, I never had issue with WD40 and plastic , cuz I use it in my house never had that problem.

PB works much better for me, stuck bolts, ahh yea. plastic? nah, I use something else if I see plastic.