Welcome to the North American Subaru Impreza Owners Club Monday March 18, 2019
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 02-14-2019, 04:58 AM   #1
Chi_San
Scooby Guru
 
Member#: 53558
Join Date: Jan 2004
Chapter/Region: NWIC
Location: Deadford, OR
Vehicle:
2005 Baja Turbo
White/Silver/Black 3tone

Default Is my ECU shot?

Back story: I bought my Baja Turbo around 3/4 of a year ago. I drove it home after purchasing, and I noticed some problems with it.

The biggest thing I noticed was the idle kinda sucked. It wanted to die at stop lights, and if I was sitting at a light with the turn signal on, the headlights dimmed quite noticeably when the turn signal turned on, and brighten back up when it went off.

So, I immediately took it to a battery store, and threw the battery on a tester. Had basically no capacity left in it, it was shot. So, I replaced the battery with a brand new battery, and hoped, problem solved. I also took the alternator down to an O'Reillys autoparts, and had it tested, which it passed.

There are no ECU codes present, nor any pending.

Why I think the ECU is borked:

1) My cruise control does not work. I can push the button, and the light turns on. Then, when I set the cruise, if the vehicle is cold, it will activate, and hold speed per normal operation, but only for anywhere between 2 and 5 minutes. The cruise will disconnect, and refuse to reconnect. I can poke the button and turn off the light, and it will come back on, but no matter what I do with the control stick, the cruise will not re-engage.

2) P0244. If I brake-boost in 3rd, 4th, or 5th, or go up a steep hill in the same gears, and floor it, after a few seconds, the ECU will report (in logging) that the boost has gone up over 19 PSI, there will be a huge 'bang', fuel cut is triggered, and a P0244 is set. Using a boost gauge, the boost never exceeds 16 PSI, though it is set for 14 PSI at th e moment.

3) Random power cuts. This is really odd, and sadly, my OpenPort2.0 died so I can't log at the moment, but it happens somewhat randomly. I'll be driving, at part throttle, and the power just... goes away. Turbo spins down, goes into engine braking. It's like I'm at 0 throttle, but the bypass valve doesn't open, the turbo doesn't surge, it just... Stops. If I let my foot off the throttle, it'll kick back in, and make the same power it should...

4) Multiple electrical issues are present. The reverse lights don't work when in reverse, unless i jiggle the stick shift. Almost every light bulb in the interior is burned out. The headunit works, but not quite right; it will randomly lose the current time, and it's little clock goes waaaaaaaaay out of sync when the car is turned off.

I guess, I'm asking, should I just drop the $$$ on a new ECU, or should I treat these issues as separate? I honestly have no idea how to even diagnose the cruise control; I have a receipt from the previous owner that shows that a dealership attempted to 'fix' the Cruise and the P0244 problems by throwing parts at the damn thing (neutral position safety switch, and a brand new boost control solenoid). Taking it to a dealer is out of the question, as the local dealership is as untrustworthy as a car dealership can be (I 'got a job there' temporarily, and watching their techs work on cars made my stomach turn).

Also... Is the 2005 STi ECU a direct, plug and play swap, or does it require repinning/replacing the wiring harness connectors?
* Registered users of the site do not see these ads.
Chi_San is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 02-14-2019, 07:45 AM   #2
defaultstivaper
Scooby Newbie
 
Member#: 486819
Join Date: Jun 2018
Location: Long Island, N.Y.
Vehicle:
2018 STI
Pure Red

Default

It very well could be the ECU, especially if no other codes are present. My 18 STI ECU was replaced 3 months into ownership and exhibited only 1 symptom which was a camshaft position sensor code. Dealer changed the sensor, and it came right back. They tracked it back to the ECU.

Long story short, a ECU can be shot without fully frying itself. It can still work in 99% of its functions or less. For me, I felt like my powerband was off ontop of the CPS code. So whatever happened to my ECU only fried a single circuit within, enough to cause this random false flag. Although it came down to the engine harness or ECU, the ECU clearly fixed it. See if you can find one for cheap.
defaultstivaper is offline   Reply With Quote
Old 02-14-2019, 08:32 AM   #3
Foo_Blyat
Scooby Guru
 
Member#: 93750
Join Date: Aug 2005
Chapter/Region: MWSOC
Default

Check all grounds. Seems more like a wiring issue and not the ecu
Foo_Blyat is offline   Reply With Quote
Old 02-14-2019, 09:05 AM   #4
Turpid Porpoise
Scooby Specialist
 
Member#: 476573
Join Date: Oct 2017
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2008 Impreza WRX STi
Silver

Default

I agree with Foo, check and clean all grounds. This sounds more like wiring than ECU to me.

I do not believe the 2005 STI ECU is plug and play or else there would most likely be an accessport available for the Baja.
Turpid Porpoise is offline   Reply With Quote
Old 02-15-2019, 04:55 AM   #5
Chi_San
Scooby Guru
 
Member#: 53558
Join Date: Jan 2004
Chapter/Region: NWIC
Location: Deadford, OR
Vehicle:
2005 Baja Turbo
White/Silver/Black 3tone

Default

Grounds is a good idea; I'll give that a shot next time I have some time off from work. Though, I should also point out that I did have to replace pretty much every external light as well, when I first got this. I had turn signals and headlights burned out. >_< I also did replace both battery terminals, as the positive terminal had some fairly serious green cancer on it. I did that at the same time I replaced the battery.

Quote:
Originally Posted by Turpid Porpoise View Post
I agree with Foo, check and clean all grounds. This sounds more like wiring than ECU to me.

I do not believe the 2005 STI ECU is plug and play or else there would most likely be an accessport available for the Baja.
Well... You 'can' get an AP to work on the Baja ECU, you just have to flash a STi map to the Baja ECU. Which is risky, and I have no intention of doing that... Nor am I interested in an AP in the first place...
Chi_San is offline   Reply With Quote
Old 02-15-2019, 07:52 AM   #6
Turpid Porpoise
Scooby Specialist
 
Member#: 476573
Join Date: Oct 2017
Chapter/Region: MAIC
Location: Virginia
Vehicle:
2008 Impreza WRX STi
Silver

Default

The light bulbs make me think you may have a short somewhere. None of the lighting is controlled by the ECU so you can separate those issues. P0244 and your power cuts could be the EBCS, wastegate actuator or MAP sensor as well as an electrical issue.
Turpid Porpoise is offline   Reply With Quote
Old 02-15-2019, 10:33 AM   #7
Fndragn
Scooby Newbie
 
Member#: 470845
Join Date: Jul 2017
Chapter/Region: MWSOC
Location: Iowa
Vehicle:
2011 Sti
DGM

Default

I have no idea what the problem could be, the only thing that throws a red flag to me is the revere lights not working. I just recently read a bunch of threads on reverse lights not working after leds had been installed. They caused an electrical issue that was shorting out other lights. None of them had the issues with the turbo though. I’m probably far off but it sounds somewhat similar. There was some talk about the leds shorting out the BIU (body integration unit). Again I’m probably way off but it’s a thought.
Fndragn is offline   Reply With Quote
Old 02-15-2019, 10:38 AM   #8
Foo_Blyat
Scooby Guru
 
Member#: 93750
Join Date: Aug 2005
Chapter/Region: MWSOC
Default

Quote:
Originally Posted by Chi_San View Post
Grounds is a good idea; I'll give that a shot next time I have some time off from work. Though, I should also point out that I did have to replace pretty much every external light as well, when I first got this. I had turn signals and headlights burned out. >_< I also did replace both battery terminals, as the positive terminal had some fairly serious green cancer on it. I did that at the same time I replaced the battery.



Well... You 'can' get an AP to work on the Baja ECU, you just have to flash a STi map to the Baja ECU. Which is risky, and I have no intention of doing that... Nor am I interested in an AP in the first place...
Def a wiring issue. My heart goes out to you because chasing down electrical demons is the worst. Look for anything thats been added, removed, spliced open, etc . after double checking your grounds

EDIT: A quick internet search of "subaru baja loose ground" came up with this post

Quote:
bpeebles Posts: 4,085
October 2009
If I were you - I would start with the grounds. (I do this to EVERY automobile I own)

As I recall, my Baja has about 7 ground-points under the hood that I cleaned-up.

This is essentually the process I use (1 ground at a time)
1) Remove holddown screw
2) Use dremel-tool, file, wire-brush (whatever) to clean up the eyelets.
3) Also clean up the point on the body so it is shiny-clean
4) Re-assemble.

Another thing I did is remove-reseat (several times) every relay in the relay-box under the hood.... again, this action cleans up the connections.

Another thing that is recommended is to clean-up the charging wire.
1)The battery MUST be disconnected to perfrom this. (remove negative wire)
2)locate large red wire that connects to alternator (this wire goes direct to battery +)
3)Remove the nut holding thie wire down
4)Clean up eyelet and connection-point
5)reassemble... make this pretty tight
6)Reconnect battery (connect negative wire)

This may not help your problem... but it is VERY good preventive-maintenance.

DISCLAIMER: If you are not comfortable with any of the above... do not attempt. (But I assume you would not be asking here if you were not expecting to DO something)
From this thread https://forums.edmunds.com/discussio...ctrical-issues where a whole bunch of baja owners experience stuff like you

Heres another good post from the outback forum

Quote:
Yikes, I sure wish you luck. An intermittent bad ground has got to be one of the hardest things to troubleshoot. I used to be an A&P mechanic, and I always hated being handed a job like this. It's a real [email protected] as to whether you will be able to find the problem.

First you need to eliminate the obvious stuff by taking apart and cleaning the battery posts and terminals, and physically inspect every ground you can easily see in the engine compartment and chassis, especially the other end of the battery negative cable and any other engine grounds. If you can access them, take them apart and clean the contact surfaces with a fine (red) scotchbrite pad, then reassemble.

If you are seeing significant corrosion on these grounds, then most likely there are others that you can't see that are also corroded. You can eliminate future problems by coating the joints, after cleaning, with liguid electrical tape, which is like a gooey vinyl fluid. You can get it at NAPA, but it's much cheaper at Walmart or another box store.



You must find a complete electrical wiring diagram, because without it the job will be impossible. Since you say "you don't know electrical stuff", you will also have to find somebody who does to help you.

Make a list of all the circuits that are causing you problems. Study the diagrams for each circuit and write down where ALL the grounds are. Try to keep your list organized, because most likely you will have a lot of grounds; when you are done, study it to see if there is one common ground that is affecting ALL the malfunctioning circuits.

It is highly unlikely that you have more than one bad ground, but that one bad ground may affect a number of different circuits.

The grounds are coded in the circuit diagrams, for example, "GND-03"; I am not sure where you find their actual location on the car, if it isn't shown in the service manual (it "should" be) maybe your Subaru dealer could help. The situation is made worse by the fact that there are also inline connectors as well as physical "bolted down" grounds. A loose or corroded inline connector will be really REALLY hard to find, since it may be taped up deep in a wire bundle.

I once had all sort of weird tail light problems on a Jeep Cherokee, and I traced the problem to a soldered ground splice behind the left rear quarter trim panel where six wires joined one large ground wire - moisture had leaked in and corroded the joint so badly that you could pull it apart by hand.

I can't get more specific, especially since you haven't said what kind of car it is. To troubleshoot your sort of problem, it just takes common sense and a lot or perseverance, and more than a little luck.

John Davies
Spokane WA USA

Last edited by Foo_Blyat; 02-15-2019 at 11:06 AM.
Foo_Blyat is offline   Reply With Quote
Old 02-19-2019, 08:31 PM   #9
Chi_San
Scooby Guru
 
Member#: 53558
Join Date: Jan 2004
Chapter/Region: NWIC
Location: Deadford, OR
Vehicle:
2005 Baja Turbo
White/Silver/Black 3tone

Default

Huh. The door dinger is dead, too. Add it to the list.
Chi_San is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 11:51 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2019 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.