Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - View Single Post

opc · 09-23-2022, 03:33 PM

Hi Gentlemen,

Reviving this old thread in hopes that someone can help me out with a few questions about fixing the P0018 engine code.

Some background

I just bought the car used a week ago, and it has been throwing the P0018 for an unknown amount of time prior to me buying it. The previous owner mentioned they brought it to Subaru to have it diagnosed and they said it just needed a "cam sensor".

I have since replaced the driver's side intake cam sensor (probably not necessary) which did nothing to fix the issue. I then swapped the intake and exhaust OCVs from left to right, and cleared the code again only to have it pop right back up next time I drove on the same side as before.

From here, it was clear it was not the sensor or OCV causing the issue.

Next step was the intake CAM sprocket which was just replaced at the Subaru dealer. This seems to have indeed fixed the issue as the car is now idling perfectly (it used to hunt for idle and dip down below 400RPM and almost stall) but the P0018 code remains. Even when cleared, it pops back up after only a short drive.

Based on everything I've read here, it seems the ECM is the last thing that will need to be replaced as it has apparently permanently learned "bad" values that cannot be overridden.

My questions:

1. When people refer to the "ECM" do they mean the main control module under the glove box in the cabin, or is it the smaller module on the passenger side of the engine in the engine bay? Both seem to be available on eBay for ~$100 and both seem to be called "ECM" interchangably. I'm not sure which I need to replace.

2. I have heard about updated ECM ROMs that can be loaded to fix this issue. Is there any point pursuing this, or is this just nonsens? Is it really true that there's no way to "reset" the ECM to default values to undo the bad values values it has learned? This seems absurd to me.

I would hugely appreciate any help on this issue. I'm supposed to have a track day on the 30th and am deperately trying to get this all fixed by then

Thanks!
Owen

09-23-2022, 03:33 PM	#62
opc Junior Member Join Date: Sep 2022 Drives: 2013 Subrau BRZ Location: Ottawa, Canada Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Hi Gentlemen, Reviving this old thread in hopes that someone can help me out with a few questions about fixing the P0018 engine code. Some background I just bought the car used a week ago, and it has been throwing the P0018 for an unknown amount of time prior to me buying it. The previous owner mentioned they brought it to Subaru to have it diagnosed and they said it just needed a "cam sensor". I have since replaced the driver's side intake cam sensor (probably not necessary) which did nothing to fix the issue. I then swapped the intake and exhaust OCVs from left to right, and cleared the code again only to have it pop right back up next time I drove on the same side as before. From here, it was clear it was not the sensor or OCV causing the issue. Next step was the intake CAM sprocket which was just replaced at the Subaru dealer. This seems to have indeed fixed the issue as the car is now idling perfectly (it used to hunt for idle and dip down below 400RPM and almost stall) but the P0018 code remains. Even when cleared, it pops back up after only a short drive. Based on everything I've read here, it seems the ECM is the last thing that will need to be replaced as it has apparently permanently learned "bad" values that cannot be overridden. My questions: 1. When people refer to the "ECM" do they mean the main control module under the glove box in the cabin, or is it the smaller module on the passenger side of the engine in the engine bay? Both seem to be available on eBay for ~$100 and both seem to be called "ECM" interchangably. I'm not sure which I need to replace. 2. I have heard about updated ECM ROMs that can be loaded to fix this issue. Is there any point pursuing this, or is this just nonsens? Is it really true that there's no way to "reset" the ECM to default values to undo the bad values values it has learned? This seems absurd to me. I would hugely appreciate any help on this issue. I'm supposed to have a track day on the 30th and am deperately trying to get this all fixed by then Thanks! Owen