Hello, I have a rare problem (I think).

I get a check engine light P0850 Pakr/Neutral Switch Input Circuit

I didn't see the issue myself, but whoever was using my car told me that twice when they parked the car, the car would not turn off and they had to switch to drive and back to park to turn it off.

So it made me think that probably issue is electrical (due to check engine light).

My questino is, should I try to replace shift lock relay? Or go straight to the shifter? Is it worth tryiing to clean it or should I just replace it with used one?

My understanding is what I need to replace or clean is the white rectangular box that is to the right of the shifter?

 

Which car (2010 or 2014) and what transmisson?

P0850, technically, has nothing to do with the shifter in the center console. P0850 points to the TCM not sending the appropriate signal to the ECM.

Do your reverse lights/ backup cam turn ON when you put the car in reverse?

 

Sorry forgot to mention. Its 2010 G37 with 7AT

Backup camera and lights work. And out of driving for 3 weeks, it wouldn't turn off when parked only 2 times.

Thanks

 

The engine would not turn OFF?
Have you ever gotten the "SHIFT TO PARK" message followed by rapid beeping when you shut the car off?

 

Yes, when vehicle in park and trying to turn ignition off, the dashboard says that vehicle needs to be in park

 

AH HA! Got it. Odd that the TCM is throwing P0850, but...

I assume you've read this thread? I would try the easiest route and spray some WD-40 (just a little, DON'T FLOOD IT) and make sure the actuator rod is clean and moving free. Once you remove the shift knøb you will see the plastic cap- this is the actuator rod. More often than not dirt, rust, and crud prevent the actuator from fully extending. Spray some WD-40 and press that cap down a few times to get everything free. That should solve the issue.

In the event the issue persists, or gets worse, then I would just find a suitable replacement on eBay and swap it out.

 

Thanks! I took it apart yesterday, but will do WD-40 trick before doing anything else!

 

Quick update, I did more tests and apparently I can turn my car off when it is in drive, reverse, or neutral. I tried to spray with WD-40 a bit, but it doesn't do anything really.

Is it normal on g37 for car to turn off if gear is in D, R, or N? (I mean turn off with push to start button)

I ordered shifter thinking that I'll just take out gear selection box out of it and replace it with mine, but I guess in G37 sedans to replace to box I have to completely remove whole center console. With that in mind, I think I'll just replace whole gear assembly since the replacement one is from 2012 vehicle.

I might make a video and post a YouTube video here when I am done in case anyone is interested.

 

Sorry the WD40 trick didn't work for you. Likely there is some dirt or corrosion in the shift module box. It is much easier to just swap out the whole shifter assembly. There are only four (4) bolts up top and the clip underneath the car from the shifter to the transmission control rod. Should take about a hour or so...

Yes, it is "normal" to be able to shut the car off while in gear. That is when you get the "Shift to Park" message with the beeping. At speed, in a emergency, you can shut the car off by holding the start button for ≈3 seconds (ONLY FOR ENERGENCIES)!!!

Please update with how you make out...

 

Hey, just a quick update. I got an assembly from eBay, but after examining it I saw that one wire was cut, so the seller gave me partial refund and I ended up replacing just two boxes on the shifter. Everything is done, no problems, and I am working on a very detailed DIY video for the procedure.

 

Here is the video, I'll also post it in DIY section