CEL code P0852 Again on the Subaru

[LoneRanger]

Numbers here will be give away to fact the car doesn't get driven as much as should. August 2015 @ 56,000 miles Forester threw a CEL and set DTC P0852 and Chassis Code C0057. 852 is Neutral Position Switch Circuit High (5-speed manual trans), and chassis code 57 is a CANBUS connectivity error associated with either the stability control, ABS, or ECM. C0057 is the fun one. CANBUS errors are just so fun to trouble shoot !!

Yesterday CEL lit w/ stability ctrl and cruise ctrl dash lights flashing, same as in 2015. That means the CEL has knocked stability control and cruise control offline. Nice !! Right as I was heading onto the interstate for a 90 min drive home from fiancee's parent's house. I did pull off and check all important fluids and such, all okay. Suspected it might be the same thing as three yrs ago. 63,800 on the odo now (that bit about not driven a lot). Got home, pulled codes, yep. Same thing again. Erased codes this morning (between bathroom visits, see fast food thread...) Went for drive once stomach was back to normal (see fast food thread), CEL did not come back on (yet). Not a loose or corroded ground strap/wire connection anywhere on the car (that I can find). Battery cables clean and tight & battery was replaced November 2017.

Some kind of random connection flake-out related to some pin on some connector somewhere in the CANBUS/harness route. Oh the humanity.

For now I'm leavin' it, but if it trips the same codes again soon, then it'll be time to take some sort of correction action such as thorough diagnostic (not equipped, refer to a shop) or follow through on that recent desire I posted about getting rid of the Forester for an Outback.

 

[14Accent]

The C0057 has two sub-definitions per Subaru. One is an actual communication error, the other is an ECM request code. Any time a CEL sets the PCM will send a disable request message to the ABS\stability control module (hence the stability light). It's completely normal.

Poking on Identifix, it appears that the most common fix is the neutral position switch. Second most common is worn shifter bushings not aligning the shifter back into neutral, and third most common is stuck\seized linkage.

I'd throw a switch at it. Should be cheap and easy.

 

[LoneRanger]

Thanks for that info, sounds like you have some shop tech experience, perhaps worked at a dealership service dept dealing with these type of things.

Ran some errands today after clearing the code and it's not come back yet. Now that I've said it's not come back, it probably will of course, since that's how my life works.

 

[14Accent]

Originally Posted By: LoneRanger
Thanks for that info, sounds like you have some shop tech experience, perhaps worked at a dealership service dept dealing with these type of things.

Ran some errands today after clearing the code and it's not come back yet. Now that I've said it's not come back, it probably will of course, since that's how my life works.

My pleasure.

No dealer service experience, I work for an Indy. We see lots of Subaru's up here in MN, everyone and their mother has one. The only place I've seen more is Washington state.

 

[Bladecutter]

Originally Posted By: 14Accent
I work for an Indy. We see lots of Subaru's up here in MN, everyone and their mother has one. The only place I've seen more is Washington state.


You should visit CO sometime.
You would swear that we have 3 different Subaru factories in our state.

BC.

 

[meep]

a coworker here bought a new outback ~3-4 years ago and had a bunch of CEL issues brand new. It was traced to a single pin on the main wiring harness where it connects at the firewall headed into the dash. in his case it was pin 19. It took a dedicated dealer tech to track it down. That single pin had not pressed all the way (extended) into place during mfr assembly.

-m