BRZ "p2158 speed sensor circuit b"
 

so i just bought my 2015 brz from the salvage auction. After getting the car home and starting it for the first time the vehicle went into immediate limp mode. After scanning i was given the code "P2158 speed sensor circuit b". after attempting to clear the code the engine will return to normal idle for 3-5 seconds then will go back to limp mode idle. Upon further inspection i deemed that the code may be due to a faulty abs sensor. After looking online at prices for sensors i decided it would be more cost effective to just buy all 4 as it was just over double the price for a single unit. Got them in the mail and installed them all making sure to be extra careful as to not mess up the sensors. and yes before all sensors were installed i did a visual check to make sure that the metal strip that they ride on was present and undamaged. After replacing all four i grounded out the battery terminals for half aan hour to reset the computer and started it back up. Same code, same limp mode, same christmas tree on the dash. after looking online to see if there was a speed senor in the transmission, i found that there was one but could not find online any information about where it is or how to change it. im out of options and as i dont have the money for an abs comppatible scanner i turn to the forums for guidance. This is my first post so sorry for any errors and i appreciate any and all feedback. Thank you and have a great day.:thanks:

Does Torque Pro app do ABS codes? I've never tried it for ABS.

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i dont believe so, i had a guy try earlier today with torque pro to analyze the code but same answer i was getting.

Is your ABS light on?

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yes abs light, check engine, traction conrtol are all on

What was the damage that caused it to be salvaged? Could be a cut or damaged wire anyplace along the line.

it appers to have been sent offroad through some sort of fence brunt of the force was crashbar and a little bit of driver front fender. some decent damage was also sustained on the driver a pillar and roof. i went through the wiring when i replaced the sensors but didnt not see ny damaged or frayed wires.

That code is for the VSS, not the wheel speed sensors.

It is transmission mounted.

https://www.subarupartsdeal.com/part...0098ab900.html

Wiring Diagram

http://www.ft86club.com/files/BRZwiringi.pdf

After further research this is incorrect. The brz aisin auto transmission has a speed sensor but the manual does not. After updating/refining the search results on the subaru speed sensor parts list the linked part does not fit the manual 6 speed. The speed for the car is determined by the 4 abs wheel speed sensors. i will use the wiring diagram for further diagnosing so i appreciate the link.

Ahhh. You are correct. One of the original search’s I had I thought showed manual but it looks like I was mistaken.


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After rereading your OP. You probably want to actually read and erase the code. I thought the ABS had to be going 7.5mph or something to even register. Anyway you have 3 extra good ones right? Also it may be a slightly different code (different location?). I just did a crankshaft position sensor in my Fiancee's car. It took a couple of days and some fairly methodical work to track down the ghost. (Including a new battery and some injector cleaner because even after a sensor that I'm confident was bad it still had a general error intermittently). I did prevail in the end but sometimes it's more than one thing. A decent multimeter and a cheap OBDII scanner are valuable tools and not expensive (certainly much cheaper than throwing parts at it all the time). If it's not a sensor it could be wiring but that's much less likely and way much more of a pita to find and fix so check those codes and test those sensors. Also make sure you clear the codes (after writing them down or emailing them to yourself from Torque Pro) because otherwise you will get all those limp mode symptoms and lights.

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My next line of attack was to ohm the sensors out to confirm they were working. I unfortunately don't have a big direction scanner that can read and codes so I can't directly determine which sensor it is. But oddly enough clearing the code does absolutely nothing. I have torque pro and it will read and delete the codes, but the issue will still persist. Once I clear the code through the app the engine will go back to normal and the cooling fans will cut off for 3-5 seconds and then the engine light will comes back on, the engine will idle in limp mode and the fans will turn back on. It will give me the same code on torque pro as it does on my other obd2 scanner. P2158 circuit b. I'm assuming it's one of the front sensors, from the pure assumption that the 4 sensors are labeled a,b,c,d whre a and b are the front and c and d are the back sensors. Pure guesswork though. I'm just curious if anyone has had a similar code and what their remedy for it was but I've found nothing online that corresponds with my current issue so it's just more troubleshooting for the time being. I appreciate all the help again and thanks for your assistance.

It's just weird that an ABS code is rearming without you moving the vehicle. I'm surprised that you haven't had to hit 8 mph to set it off.

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The abs never rearms itself, it never turns off. The only thing that turns off is the engine light