Waiting for your OBDII Codes. Not going to guess at what your issues are.

 

An easy thing to check when you suddenly get a bunch of warning lights, is the gas cap tight?
It is a cheap and easy test.

 

Further to my posting of August 18, 2025 regarding the trio of error lights, etc. that appeared, I took my Forester to the dealer from whom I had purchased. He checked for codes with his OBD reader: nothing but he said that his reader was an older model.

In any case, I followed the advice in CO17Forester’s post of June 14, 2024 : “An easy thing to check when you suddenly get a bunch of warning lights, is the gas cap tight? It is a cheap and easy test.”

I removed and retightened said gas cap. There was no immediate change but after 100km or so of driving, all the error lamps disappeared and my cruise control restored.

Thank you COForester!!!

 

Hi All,
OBD shows code P0500 "Speed Sensor A" (this is the only code)
--I don't have a shop manual, so any help here much appreciated!
Bob

 

BTW- gas cap is tight.

 

@rvander8
All the lights on the dash lighting up are Subaru normal for anything that goes wrong.
This article on the P0500 code may help - There are more than a few possible causes.

Someone on an Outback forum has a good write up of his adventure with that same problem.
You are likely going to need some investigative work to determine the cause, as these are varied.
Good luck.

 

Solved- at least temporarily!
Thanks for the help.
Somewhere (google) someone said disconnect the battery and short the disconnected cables for 20-30 seconds: I did this and all the dash lights disappeared with what appeared on ignition startup to be some sort of system reset. Drove the car for a few miles and no recurrent lights or codes. Obd shows the P0500 as "permanent"-otherwise all OBD looks good.
I hope this isn't an intermittant bad connection!?!?
I'll find out soon enough1
Bob

 

Disconnecting the battery & attempting to discharge volatile memory got you temporary relief. But as you see the code is hanging on. They sometimes do.

Your code reader likely has a 'clear all' feature. That is a better way to do it, and often more effective. It addresses the stored code and freezeframe data stored with it, while not wiping out all the ECU/TCU learning accumulated over miles of driving.

If you haven't addressed the root cause, you'll unfortunately most likely be back when it happens again.

 

Fibber2,
You were right-- I drive 30 miles home every day, and this afternoon, at about 15 miles, all the same lights came back to the dash. I noticed the speedometer and odometer are both still working.
Can you, or someone else tell me if the P0500 "Vehicle speed sensor" code refers to a wheel speed sensor or a central engine, crank, or driveshaft sensor? The fact that the speedometer on the dash is still working and the trans is shifting OK (seems to drive fine)-- really has me puzzled-because I don't know how this stuff communicates, and without a true OBD diagnostic tool and Shop Service Manual-- I'm not sure how to proceed. I've done a lot of work on cars and other equipment so I'm not afraid to "dig in"- but I need a map. My car mechanic friend said people like Autel OBD software-- what do you guys recommend?
I'm getting ready to get a better OBD setup. I just have a 2014 code scanner- which just throws the P0500 code.
Thanks in advance for any and all advice.
Bob

 

Sorry to hear that. Truthfully. Unfortunately just wishing it away rarely works.

Speed sensor on Toyota vehicles often seems to be associated with a tranny shaft speed module. On Subaru it more likely applies to wheel hub sensors or the ABS/Stability module that governs the brake fluid pump. It's likely that in addition to the Pxxxx (powertrain) code there is also a Cxxxx (brake hardware, wheel rotation monitor) code involved.

Most generic readers are good with Pxxxx codes, but Cxxxx and others are generally proprietary to each manufactor. Until a few years ago, it cost you a lot extra to manufacturer-specific access, but those barrier are falling. I use the AutoEnginuity laptop system, and the extra licensing is crazy. When I work on my Toyota, I use TechStream on a laptop.

I saw that some Autel handhelds do now include some coverage, as do even sub $150 units at Harbor Freight.

 

Fibber2,
I see you own a '18 Forester Limited-- which scanner do you use on that?
--Also will the newer scanners tell me which of the four wheels to concentrate on?
I looked into Vagcom for an Audi we had about 10 years ago, but it was rediculously expensive for a DIY mechanic like me so I passed. Glad to hear the proprietary info is more widely/cheaply available.
thanks again.
Bob

 

Another question for you guys:
Do you think it's safe to drive this car?

The dash lights that are on are for Dynamic Vehicle Control and ABS (the ones I think that count the most). The transmission light is not on. I could easily be wrong, but I don't think it's too big of a problem if I drive without: ABS, Lane Change Assist, X-drive (not on), Hill Start Assist System or the Cruise Control (also not on). The only "blinking lights" are the Cruise Control and X-drive.
The car drove and shifted fine for the last 10 miles of my trips home yesterday and today: good RPMs and no jerky shifting, braking etc.


----I need the car this weekend and it will be at least a few days until I get better diagnostic OBD tools, and parts.

Many thanks!
Bob

 

I have not yet had any reason to plug anything into the OBD port of either Forester other than my Autel TS508 TPMS reset tool for winter tire / summer tire exchanges. If I get a chance over the weekend, I might charge up the laptop with AutoEnginuity and see if it will communicate. It should.... I used it on my 2014 Outback a few years ago.

 

Fibber2--thanks

 

I got a BlueDriver OBD scanner and saw codes C1222 (FL WHEEL SPEED SENSOR SYSTEM) along with P0500. With limited knowledge of how all these codes interact, it seemed reasonable that a wheel speed sensor could cause the other problems--so I replaced the front left wheel speed sensor (I had worked on the left front end 6 months ago to replace the LF axle/CV joints and I though I might have damaged this sensor). After clearing all codes I drove about 100 miles with a clean dash, then all the codes came back:
P0500 Vehicle Speed Sensor "A" Circuit (Uncommon according to BlueDriver)
C1222 FL WHEEL SPEED SENSOR SYSTEM (Rare according to BlueDriver)
C1424 ECM FAILURE (Common according to BlueDriver)
C1431 AT ABNORMAL
(and two "Rear Vehicle Detection Codes" which I think are unrelated: B2313 and B2311, suddenly the front passenger side window will not open from the drivers side switch-- it will open from the front pass side switch).

2018 Subaru Forester 2.5i Limited, 150,000 miles.

The Car still drives fine. The lights that came back on are the same ones that were on when the whole problem started so obviously I have fixed nothing:
Check Engine
ABS
Vehicle Dynamic Control
Hill Start Assist System
Cruise Control
X Mode
Lane change assist (lights on mirror warning of car in blind quarter.

I have downloaded a pdf of the Service Manual.

I would like to fix this myself, but I don't want to continue to replace parts to "see if this works". Can someone tell me how to proceed in diagnosing the actual problem in this forest of codes and lights? (or do you recommend I just give up and take it to a dealer?).

Thanks in advance for any/all help--
Bob

 

Forgot to add the latest scan report:

 

If you had the battery disconnected, the passenger window needs to be reset from the passenger door switch, then it will work from the drivers side switch.

The P0500 code tells you to check the VDC trouble codes.
DTC C1222 like C1212 and C1232, use the C1242 diagnostic procedure.
DTC C1424 and C1431 are VDC ECM failure codes, I would work on the C1222 problem first.

When these procedures call for an inspection

When they call to clear the memory, use the scanner to clear the codes.


Good luck

 

Assumptions : With all the Electronics, and Digital Components in Vehicles these days, it is Too-Easy to "assume" that all the Electrical-Information is "accurate" , and only that the unknown problem is "The-Problem" !!! Chances are that Only-One-Piece-Of-Equipment is mis-behaving, but it is causing multiple things to have digital (codes) Hissy-Fits;

Your best Assumptions can be derived from looking at Common Physical Location(s) for Un-Common Problems; and the most likely starting point should be Local-Area-Grounds;
Such as a rusted Ground can affect everything in a Physical Location, including things that have no other commonality or interaction(s) !!!!! In your case , sounds like everything spitting out "codes" are all located in the Front-Left Quarter-Panel Area !!!! Dig into your Grounding Network for some possible solutions.

 

I took the car to a place that had the Subaru software and it came up with a bad left front wheel sensor or tone ring, and the tech looked at the tone ring (on the inside of the bearing on this car) and said it was bad. I took the car back (58 bucks for the diagnostics) and replaced the LF wheel bearing/hub assembly with one from Amazon and things have been great (all lights gone) for two months. I looked at the "tone ring" on the inside of the bearing I removed and it was VERY rough--so the tech was right. Next time I'll take it sooner for diagnosis if lights come on, then do the repair myself.
Thanks for the help on this forum.

 

Thanks for the follow-up @rvander8