How to test boost control solenoid

94'325is · 08-16-2007, 07:46 PM

So I think my boost control solenoid is sticking and I was wondering how I can open it to spray with non-chlorinated brake cleaner. I know I'm supposed to send 12v through it, but I'm not sure how to go about that.

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avesfan101 · 08-16-2007, 09:29 PM

take the solenoid out of the car then take two pieces of wire with each end stripped and hook one end of each to each of the sides of of a car battery. then take the other end of one of the wires and hold it on one side of the electrical tabs on the solenoid. then take the other wire and tap it to the other tab on the solenoid. you should hear it click every time you tap it on and off. now spray some of the non chlorinated brake cleaner into the ports and cycle it through a ton of times and you should be good to go. ive heard of people opening them up but it wasnt needed to unstuck mine.

94'325is · 08-16-2007, 10:33 PM

I just did that and now my car only hits 7 psi in 1st and 2nd and 9 psi in third and fourth. Does it sound like I have a bad solenoid?

quazimoto · 08-17-2007, 07:13 AM

Sounds like the vacuum line pill for the turbo is missing

twizzstyle · 08-17-2007, 03:21 PM

Quote:

Originally Posted by 94'325is

I just did that and now my car only hits 7 psi in 1st and 2nd and 9 psi in third and fourth. Does it sound like I have a bad solenoid?

When I originally cleaned mine, I didn't take it apart. I spray cleaner in it, cycled it on the battery, let it dry and put it on the car. Only got wastegate boost (7 psi).

Take the solenoid back off the car, and try it on the battery again. I bet you you won't hear any *click* as the valve seal is probably stuck shut. (thats what happened on mine)... that's why I took it apart. By taking it apart, I got the seal free again, put it back together, tried it on the battery and it worked fine, back on the car and I'm hitting full boost no problem.

So your next step is to try the solenoid on the battery again... does it click?

94'325is · 08-17-2007, 05:54 PM

I just got back from cleaning it and it clicked and I sprayed brake fluid through it. I put it back on and now I'm hitting 18 lbs in 3rd, 4th and 5th and 15lbs in 1st. I also tightened the vacuum line from the t-fitting to the wastegate actuator as there was no clamp holding it on.

94'325is · 08-18-2007, 12:23 AM

Well I was on the highway in 4th gear and I floored it and I heard a loud boom and then the CEL came on with a P0221 code. I then took off the solenoid and it wasn't holding pressure. I ran power to it and it sounded like it was opening and closing but it still didn't hold pressure. The car still makes full boost in 1st and 2nd gear though. Does anyone know where I can buy a new solenoid at?

quazimoto · 08-18-2007, 07:12 AM

The obvious answer is the dealership.The not so obvious would be listing in the WTB section in the forum.

Broxma · 09-16-2007, 12:32 AM

So I am working this issue, trying to get some answers in another post, but I have some stuff to add to the testing with the battery idea.

The amperage of the 12v at the battery is much greater than the 12V from the harness. The battery will actually be able to actuate the Solenoid when the 12v from the harness will not.

So it is possible that the BCS is bad, wont work when connected, but you can force it to open with the battery due to the larger power at the battery. Of course, we are a skeptical bunch so lets show some numbers.

BCS, out of car, resistance across the pins is 33 Ohms, I believe this is high meaning its bad.
Optima red top battery, known good, Voltage measures 12.5+
Harness for the BCE, known good, Voltage measures 12.5+
When I click the connector onto the BCS and measure the voltage at the harness, it drops from 12.5 to 24.5 mv. The resistance is too high inside the BCS and prevents it from operating, forcing a low voltage return to the ECU. ECU throws BCS low voltage code, BCS remains closed and you run WG pressure.

So, how to test the solenoid?
Check resistance across the pins. If it is 33 like mine, I will believe it is bad until I hear from a person with a known working BCS that also reads 33. my basic math tells me the resistance should be closer to 2-5 ohms, probably 2 .

Again, waiting on a known good resistance check across the pins to confirm my suspicion.

/Brox

DrD · 09-16-2007, 01:36 PM

for the 02, anyway, the service manual shows that the resistance between the pins for the wastegate control solenoid should be between 30 and 34 ohms, so 33 sounds just fine... looking at the manual for the STi, it shows 30 to 40 ohms, so in that case 33 would be just fine, too...

daveyboy · 09-16-2007, 06:04 PM

Not to hijack, but I am having a boost issue as well. I checked my BCS using a voltmeter (it read 35 ohms) and by jumping the battery (it clicked just fine and I could blow through it). My problem is that I should be getting 17-18 psi of boost, but I am only getting ~12. If pull the vacuum line to the wastegate, however, and drive it carefully, I will hit 17-18 psi--does that indicate that the BCS is indeed bad? If not, what else could it be?

Jonx1218 · 09-16-2007, 06:49 PM

sorry to hijack your thread but. im also haveing a terrible boost problem. i have an 02 wrx with just up pipe, downpipe w/ electronic cutout, aem short ram intake. im having a horrific time trying to get it to hold boost. i have the stage 2 map off cobb. uploaded. ok now i jus took it to the shop and they fixed all the vaccum leaks or whatnot for me. now i get back in the car everything drives fine 3rd gear holds about 15.5 to 16 lbs of boost and then for soem reason after 6000 rpms the boost drops down to 11 or 12. im thinking it could be either the stock boost controler, the fact that theres a short ram intake on it instead of a stock air assembly or the wastegate actuator. can anyone help me with this. i would post my own thread but im new to this forum so i cant do it yet.

ride5000 · 09-17-2007, 03:00 PM

Quote:

Originally Posted by Broxma

The amperage of the 12v at the battery is much greater than the 12V from the harness. The battery will actually be able to actuate the Solenoid when the 12v from the harness will not.

this is highly unlikely, and if true, would indicate a problem with the remainder of the boost control driving circuit.

Quote:

So it is possible that the BCS is bad, wont work when connected, but you can force it to open with the battery due to the larger power at the battery.

again this would be the case if there were too much internal resistance along the circuit path between battery and solenoid. not very likely unless you've blown your BCS driver transistor in the ecu, or damaged the underbonnet wiring harness.

Quote:

Check resistance across the pins. If it is 33 like mine, I will believe it is bad until I hear from a person with a known working BCS that also reads 33. my basic math tells me the resistance should be closer to 2-5 ohms, probably 2 .

2 ohms?

are you really intending to pull 6a of current through a tiny little solenoid?

ken

Broxma · 09-17-2007, 09:29 PM

Testing leads to theory. Theory is confirmed or squashed by more testing.

So we first gather some info, then go about testing. This will sorta explain how I arrived at a 2 Ohm figure, which I now know is wrong, because someone told me finally, however the results I had at the time pointed to this.

First, an ECU pinout located at http://www.northursalia.com/modifica...ng/wrxpin.html. It's an 02, but identical to the 03.

Second, http://forums.nasioc.com/forums/show...ighlight=P0246 a post about this issue where Uncle Scotty has what appears to be a Tech diagnosis step by step. Point of confusion here is that d-16 is called Purge Control solenoid and d-24 is called wastegate control solenoid and I have seen reference to both in separate diagnosis posts. I tested both when applicable.

So, my resistance across my BCS is 33. I have 12.5+ volts at the end of the harness, key on.

I ohmed the wire from the ECU Pin D-24 to the connector at the end of the harness and it ohm's at 0.00. I tested voltage from Pin D-24 of the ecu, key on, to chassis ground and measured it at 10.5 m Volts. Pin d-16 also reads 10.5 m Volts even though I believe it is actually d-24 I should be worrying about. This takes care of step 1 and 3.

Resistance between the Connector and Engine ground is well over 10 Ohms, taking care of number 2.

As stated earlier, resistance between posts on the Solenoid is 33, taking care of number 4.

I already know I have more than 10 Volts at the solenoid as I have checked it more than 25 times by now, so step 5 is a mute point.

Step 6 I had to be creative, but I basically put a single strand of wire to fill in any suspected gap between the connector and the pins on the solenoid and bent the connector contacts up to ensure they meet the pins. I also cleaned them off with rubbing alcohol, just to be sure. This actually is the hardest to test but also the least likely fault.

So, according, to all 6 steps, I pass. But...
Turn on the car, P0246 High BCS voltage CEL and wastegate pressure.

So how did I come to the 2 ohm number you ask? Well when I had no word on the stock/working BCS resistance and considering that everything else was good, I was FORCED to assume the BCS is bad. I had to assume 33 Ohms is too high. This of course makes no sense now because if the resistance is too high it would read P0245 low voltage, but I had been unable to pull codes for a while due to some driver issues on my laptop and had previously pulled a 0245 code the day before when I left the connector off by accident. And basically, there is another mis-informational post out there that said the resistance should be between 3 and 5, but 2 seemed like a good number since it was a factor of 32 and all and I like things to fit nicely.

So, if anyone could explain my BCS passing every qualifying test according to what appears to be the Soa Diagnosis diagram, yet not functioning, I'll be glad to send a sawbuck their way.

/Brox

Broxma · 09-17-2007, 09:55 PM

Updates.

d-16 Ohm's Zero to one of the BCS connectors and d-24 Ohm's zero to the other.

/Brox

BrandonDrums · 01-12-2008, 01:18 PM

I wish I saw this thread before...

I have a big boost problem. I just replaced my turbo as mine was leaking a little oil. I put the new one on and I get only 8-9 psi. So After checking for the boost leaks and the BC system I conclude my BCS is either bad or siezed and I was getting spikes before. I upgraded to a Perrin BCS and I have the exact same problem. I'm starting to think I have a bigger problem with the electrical system. Does anyone know how to test to see if the signal is even coming through the wires to the BCS?

MasterKwan · 01-12-2008, 01:56 PM

Simple trouble-shooting says, if you had full boost before swapping turbo's and don't afterwards then the turbo install was done wrong. It doesn't suggest there's a problem with the BCS. You could disconnect the vacuum line from the wastegate and see if you can get close to stock boost. Be very careful though because you can overboost and kill your motor by doing this.

If it was me, I'd disconnect and plug the wastegate line and slowly try to build boost. If it gets close to/to stock boost, then the problem is in the boost control. If you still can't go over 8-9 PSI then you have a bad turbo or a boost leak.

Don't blame me if you blow up your motor. You won't if you do this carefully.

BrandonDrums · 01-12-2008, 02:13 PM

I already did all of that, the turbo is perfectly fine. I have removed the BC vacuum hoses and I get overboost like crazy. I have no exhaust leaks or boost leaks, I have tested for both. My BC lines are clear, I have tested those. My BCS is brand new and functioning, something else with my Boost Control is awry, probably electrical. Thanks for the input though.

*edit*

Also, my WGA isn't stuck, if it was it would remain stuck when I take the BC hoses off.

Haelan · 01-12-2008, 02:28 PM

If the BCS circuit was not operating properly electrically, chances are you'd have a P0246 code.

Look for the restrictor pill in the new turbo's boost control lines. Make sure it's in there and in the right spot.

BrandonDrums · 01-12-2008, 02:42 PM

The Pill is there. I can't get anyone to say anything differently about this whole thing. Everyone tells me to check the pill. I'm thinking of taking some. I did get a code but I induced the code by running the car and disconnecting/reconnecting the BCS. Not something you want to do but someone suggested I do it to see if the ECU was even responding to the BCS. It is because I thew the code but it did not fix the problem. I'm still having low boost issues. Looks like I'm going to have to take it in to get some more stuff checked out.

Also, the new turbo is just another TD04 from Deadbolt, it's actually the Monster TD04 but it doesn't come with new BCS hoses. I re-used the same exact hoses from before and they are in great shape. I didn't touch the pill and I can literally blow the lines with my mouth and feel the pill is restricting and all the paths are clear. The BCS is simply not working and it's not the BCS its self.

MasterKwan · 01-12-2008, 03:11 PM

Since you didn't bother to explain what you've tested and how, what do you expect? Wastegate's popping open and you're not hitting target boost but, the turbo's capable of hitting more than target boost.

That suggests, BCS, Tune, Wiring or ECU. I'd swap out the BCS if you're sure the thing's plumbed right.

Haelan · 01-12-2008, 03:20 PM

I disconnected my BCS at one point for cleaning. After re-installing it I wasn't hitting anything but wastegate pressure--no codes, nothin. I reset the ECU and it went back to normal.

Have you tried a reset yet?

The ECU can turn off the boost system for various reasons including the overall health of the car. Try wiping the slate clean.

racerpj · 02-18-2008, 11:26 PM

I disconnected the vacuum hose to my actuator and still I get only 9 psi. does this mean there's something wrong with my vf39 or that there is a boost leak somewhere else?

05 sti, fmic, tbe

quazimoto · 02-19-2008, 10:38 AM

Did you pressure test the system yet?Also has this happened ever since you installed it or just started happening?You gotta paint the picture better,more details the better.Could even be a preturbo exhaust leak.

02_blue_u_away · 02-20-2008, 12:32 AM

Today my BCS ,that i just recently bought, went out on me AGAIN...Took it off, cleaned it, checked the vacuum lines, did all of these tests that are stated above and it checked out okay. But everytime i went back to install it again and reset the ECU, i still couldn't reach target boost. 20 tries later, my battery finally went out on me. Went and bought a new battery, reset ECU, and reconnected the BCS and, *"VOILA"*, boost is BACK.....

So, i guess that the battery, for some odd reason, was able to crank my engine up but not enough to power my BCS...how weird....can enyone tell me what i did wrong or did not do completely...because I still do not believe that all i had to do was buy a new battery.

08-16-2007, 07:46 PM	#1
94'325is Scooby Specialist Member#: 122315 Join Date: Aug 2006 Chapter/Region: South East Location: Tampa/Orlando Vehicle: 2003 WRX OBP	How to test boost control solenoid So I think my boost control solenoid is sticking and I was wondering how I can open it to spray with non-chlorinated brake cleaner. I know I'm supposed to send 12v through it, but I'm not sure how to go about that. * Registered users of the site do not see these ads.

01-12-2008, 02:13 PM	#18
BrandonDrums Scooby Newbie Member#: 118630 Join Date: Jun 2006 Chapter/Region: South East Vehicle: 2005 Wrx wagon Red	I already did all of that, the turbo is perfectly fine. I have removed the BC vacuum hoses and I get overboost like crazy. I have no exhaust leaks or boost leaks, I have tested for both. My BC lines are clear, I have tested those. My BCS is brand new and functioning, something else with my Boost Control is awry, probably electrical. Thanks for the input though. edit Also, my WGA isn't stuck, if it was it would remain stuck when I take the BC hoses off. Last edited by BrandonDrums; 01-12-2008 at 02:15 PM. Reason: content

01-12-2008, 02:42 PM	#20
BrandonDrums Scooby Newbie Member#: 118630 Join Date: Jun 2006 Chapter/Region: South East Vehicle: 2005 Wrx wagon Red	The Pill is there. I can't get anyone to say anything differently about this whole thing. Everyone tells me to check the pill. I'm thinking of taking some. I did get a code but I induced the code by running the car and disconnecting/reconnecting the BCS. Not something you want to do but someone suggested I do it to see if the ECU was even responding to the BCS. It is because I thew the code but it did not fix the problem. I'm still having low boost issues. Looks like I'm going to have to take it in to get some more stuff checked out. Also, the new turbo is just another TD04 from Deadbolt, it's actually the Monster TD04 but it doesn't come with new BCS hoses. I re-used the same exact hoses from before and they are in great shape. I didn't touch the pill and I can literally blow the lines with my mouth and feel the pill is restricting and all the paths are clear. The BCS is simply not working and it's not the BCS its self. Last edited by BrandonDrums; 01-12-2008 at 02:45 PM. Reason: Content

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08-16-2007, 09:29 PM	#2
avesfan101 Scooby Newbie Member#: 143332 Join Date: Mar 2007 Chapter/Region: MWSOC Location: chicago, IL Vehicle: 2004 wrx wagon stg 2 psm	take the solenoid out of the car then take two pieces of wire with each end stripped and hook one end of each to each of the sides of of a car battery. then take the other end of one of the wires and hold it on one side of the electrical tabs on the solenoid. then take the other wire and tap it to the other tab on the solenoid. you should hear it click every time you tap it on and off. now spray some of the non chlorinated brake cleaner into the ports and cycle it through a ton of times and you should be good to go. ive heard of people opening them up but it wasnt needed to unstuck mine.

08-16-2007, 10:33 PM	#3
94'325is Scooby Specialist Member#: 122315 Join Date: Aug 2006 Chapter/Region: South East Location: Tampa/Orlando Vehicle: 2003 WRX OBP	I just did that and now my car only hits 7 psi in 1st and 2nd and 9 psi in third and fourth. Does it sound like I have a bad solenoid?

08-17-2007, 07:13 AM	#4
quazimoto Scooby Guru Member#: 70395 Join Date: Sep 2004 Chapter/Region: MAIC Location: Da-boonies,Va	Sounds like the vacuum line pill for the turbo is missing

08-17-2007, 05:54 PM	#6
94'325is Scooby Specialist Member#: 122315 Join Date: Aug 2006 Chapter/Region: South East Location: Tampa/Orlando Vehicle: 2003 WRX OBP	I just got back from cleaning it and it clicked and I sprayed brake fluid through it. I put it back on and now I'm hitting 18 lbs in 3rd, 4th and 5th and 15lbs in 1st. I also tightened the vacuum line from the t-fitting to the wastegate actuator as there was no clamp holding it on.

08-18-2007, 12:23 AM	#7
94'325is Scooby Specialist Member#: 122315 Join Date: Aug 2006 Chapter/Region: South East Location: Tampa/Orlando Vehicle: 2003 WRX OBP	Well I was on the highway in 4th gear and I floored it and I heard a loud boom and then the CEL came on with a P0221 code. I then took off the solenoid and it wasn't holding pressure. I ran power to it and it sounded like it was opening and closing but it still didn't hold pressure. The car still makes full boost in 1st and 2nd gear though. Does anyone know where I can buy a new solenoid at?

08-18-2007, 07:12 AM	#8
quazimoto Scooby Guru Member#: 70395 Join Date: Sep 2004 Chapter/Region: MAIC Location: Da-boonies,Va	The obvious answer is the dealership.The not so obvious would be listing in the WTB section in the forum.

09-16-2007, 12:32 AM	#9
Broxma Scooby Specialist Member#: 158006 Join Date: Aug 2007 Chapter/Region: TXIC Location: San Antonio Vehicle: 2003 WRX IdleWagon 1992 GVR4 379/1000	So I am working this issue, trying to get some answers in another post, but I have some stuff to add to the testing with the battery idea. The amperage of the 12v at the battery is much greater than the 12V from the harness. The battery will actually be able to actuate the Solenoid when the 12v from the harness will not. So it is possible that the BCS is bad, wont work when connected, but you can force it to open with the battery due to the larger power at the battery. Of course, we are a skeptical bunch so lets show some numbers. BCS, out of car, resistance across the pins is 33 Ohms, I believe this is high meaning its bad. Optima red top battery, known good, Voltage measures 12.5+ Harness for the BCE, known good, Voltage measures 12.5+ When I click the connector onto the BCS and measure the voltage at the harness, it drops from 12.5 to 24.5 mv. The resistance is too high inside the BCS and prevents it from operating, forcing a low voltage return to the ECU. ECU throws BCS low voltage code, BCS remains closed and you run WG pressure. So, how to test the solenoid? Check resistance across the pins. If it is 33 like mine, I will believe it is bad until I hear from a person with a known working BCS that also reads 33. my basic math tells me the resistance should be closer to 2-5 ohms, probably 2 . Again, waiting on a known good resistance check across the pins to confirm my suspicion. /Brox

09-16-2007, 01:36 PM	#10
DrD Scooby Guru Member#: 22412 Join Date: Aug 2002 Chapter/Region: SWIC Location: Albuquerque, NM Vehicle: 2012 Legacy 2.5GT Ice Silver Metallic	for the 02, anyway, the service manual shows that the resistance between the pins for the wastegate control solenoid should be between 30 and 34 ohms, so 33 sounds just fine... looking at the manual for the STi, it shows 30 to 40 ohms, so in that case 33 would be just fine, too...

09-16-2007, 06:04 PM	#11
daveyboy Scooby Specialist Member#: 35419 Join Date: Apr 2003	Not to hijack, but I am having a boost issue as well. I checked my BCS using a voltmeter (it read 35 ohms) and by jumping the battery (it clicked just fine and I could blow through it). My problem is that I should be getting 17-18 psi of boost, but I am only getting ~12. If pull the vacuum line to the wastegate, however, and drive it carefully, I will hit 17-18 psi--does that indicate that the BCS is indeed bad? If not, what else could it be?

09-16-2007, 06:49 PM	#12
Jonx1218 Scooby Newbie Member#: 158267 Join Date: Sep 2007 Chapter/Region: Tri-State Location: JerZ Vehicle: 2002 wrx black	sorry to hijack your thread but. im also haveing a terrible boost problem. i have an 02 wrx with just up pipe, downpipe w/ electronic cutout, aem short ram intake. im having a horrific time trying to get it to hold boost. i have the stage 2 map off cobb. uploaded. ok now i jus took it to the shop and they fixed all the vaccum leaks or whatnot for me. now i get back in the car everything drives fine 3rd gear holds about 15.5 to 16 lbs of boost and then for soem reason after 6000 rpms the boost drops down to 11 or 12. im thinking it could be either the stock boost controler, the fact that theres a short ram intake on it instead of a stock air assembly or the wastegate actuator. can anyone help me with this. i would post my own thread but im new to this forum so i cant do it yet.

09-17-2007, 09:29 PM	#14
Broxma Scooby Specialist Member#: 158006 Join Date: Aug 2007 Chapter/Region: TXIC Location: San Antonio Vehicle: 2003 WRX IdleWagon 1992 GVR4 379/1000	Testing leads to theory. Theory is confirmed or squashed by more testing. So we first gather some info, then go about testing. This will sorta explain how I arrived at a 2 Ohm figure, which I now know is wrong, because someone told me finally, however the results I had at the time pointed to this. First, an ECU pinout located at http://www.northursalia.com/modifica...ng/wrxpin.html. It's an 02, but identical to the 03. Second, http://forums.nasioc.com/forums/show...ighlight=P0246 a post about this issue where Uncle Scotty has what appears to be a Tech diagnosis step by step. Point of confusion here is that d-16 is called Purge Control solenoid and d-24 is called wastegate control solenoid and I have seen reference to both in separate diagnosis posts. I tested both when applicable. So, my resistance across my BCS is 33. I have 12.5+ volts at the end of the harness, key on. I ohmed the wire from the ECU Pin D-24 to the connector at the end of the harness and it ohm's at 0.00. I tested voltage from Pin D-24 of the ecu, key on, to chassis ground and measured it at 10.5 m Volts. Pin d-16 also reads 10.5 m Volts even though I believe it is actually d-24 I should be worrying about. This takes care of step 1 and 3. Resistance between the Connector and Engine ground is well over 10 Ohms, taking care of number 2. As stated earlier, resistance between posts on the Solenoid is 33, taking care of number 4. I already know I have more than 10 Volts at the solenoid as I have checked it more than 25 times by now, so step 5 is a mute point. Step 6 I had to be creative, but I basically put a single strand of wire to fill in any suspected gap between the connector and the pins on the solenoid and bent the connector contacts up to ensure they meet the pins. I also cleaned them off with rubbing alcohol, just to be sure. This actually is the hardest to test but also the least likely fault. So, according, to all 6 steps, I pass. But... Turn on the car, P0246 High BCS voltage CEL and wastegate pressure. So how did I come to the 2 ohm number you ask? Well when I had no word on the stock/working BCS resistance and considering that everything else was good, I was FORCED to assume the BCS is bad. I had to assume 33 Ohms is too high. This of course makes no sense now because if the resistance is too high it would read P0245 low voltage, but I had been unable to pull codes for a while due to some driver issues on my laptop and had previously pulled a 0245 code the day before when I left the connector off by accident. And basically, there is another mis-informational post out there that said the resistance should be between 3 and 5, but 2 seemed like a good number since it was a factor of 32 and all and I like things to fit nicely. So, if anyone could explain my BCS passing every qualifying test according to what appears to be the Soa Diagnosis diagram, yet not functioning, I'll be glad to send a sawbuck their way. /Brox

09-17-2007, 09:55 PM	#15
Broxma Scooby Specialist Member#: 158006 Join Date: Aug 2007 Chapter/Region: TXIC Location: San Antonio Vehicle: 2003 WRX IdleWagon 1992 GVR4 379/1000	Updates. d-16 Ohm's Zero to one of the BCS connectors and d-24 Ohm's zero to the other. /Brox

01-12-2008, 01:18 PM	#16
BrandonDrums Scooby Newbie Member#: 118630 Join Date: Jun 2006 Chapter/Region: South East Vehicle: 2005 Wrx wagon Red	I wish I saw this thread before... I have a big boost problem. I just replaced my turbo as mine was leaking a little oil. I put the new one on and I get only 8-9 psi. So After checking for the boost leaks and the BC system I conclude my BCS is either bad or siezed and I was getting spikes before. I upgraded to a Perrin BCS and I have the exact same problem. I'm starting to think I have a bigger problem with the electrical system. Does anyone know how to test to see if the signal is even coming through the wires to the BCS?

01-12-2008, 01:56 PM	#17
MasterKwan Scooby Guru Member#: 98961 Join Date: Oct 2005 Chapter/Region: MAIC Location: NOVA Vehicle: 2003 WRX Black	Simple trouble-shooting says, if you had full boost before swapping turbo's and don't afterwards then the turbo install was done wrong. It doesn't suggest there's a problem with the BCS. You could disconnect the vacuum line from the wastegate and see if you can get close to stock boost. Be very careful though because you can overboost and kill your motor by doing this. If it was me, I'd disconnect and plug the wastegate line and slowly try to build boost. If it gets close to/to stock boost, then the problem is in the boost control. If you still can't go over 8-9 PSI then you have a bad turbo or a boost leak. Don't blame me if you blow up your motor. You won't if you do this carefully.

01-12-2008, 02:28 PM	#19
Haelan Scooby Specialist Member#: 151045 Join Date: Jun 2007 Location: NW Indiana Vehicle: 2013 Subaru STI CBP	If the BCS circuit was not operating properly electrically, chances are you'd have a P0246 code. Look for the restrictor pill in the new turbo's boost control lines. Make sure it's in there and in the right spot.

01-12-2008, 03:11 PM	#21
MasterKwan Scooby Guru Member#: 98961 Join Date: Oct 2005 Chapter/Region: MAIC Location: NOVA Vehicle: 2003 WRX Black	Since you didn't bother to explain what you've tested and how, what do you expect? Wastegate's popping open and you're not hitting target boost but, the turbo's capable of hitting more than target boost. That suggests, BCS, Tune, Wiring or ECU. I'd swap out the BCS if you're sure the thing's plumbed right.

01-12-2008, 03:20 PM	#22
Haelan Scooby Specialist Member#: 151045 Join Date: Jun 2007 Location: NW Indiana Vehicle: 2013 Subaru STI CBP	I disconnected my BCS at one point for cleaning. After re-installing it I wasn't hitting anything but wastegate pressure--no codes, nothin. I reset the ECU and it went back to normal. Have you tried a reset yet? The ECU can turn off the boost system for various reasons including the overall health of the car. Try wiping the slate clean.

02-18-2008, 11:26 PM	#23
racerpj Scooby Newbie Member#: 96523 Join Date: Sep 2005 Chapter/Region: BAIC Location: San Jose, CA Vehicle: 05 STi Rally Blue	I disconnected the vacuum hose to my actuator and still I get only 9 psi. does this mean there's something wrong with my vf39 or that there is a boost leak somewhere else? 05 sti, fmic, tbe

02-19-2008, 10:38 AM	#24
quazimoto Scooby Guru Member#: 70395 Join Date: Sep 2004 Chapter/Region: MAIC Location: Da-boonies,Va	Did you pressure test the system yet?Also has this happened ever since you installed it or just started happening?You gotta paint the picture better,more details the better.Could even be a preturbo exhaust leak.

02-20-2008, 12:32 AM	#25
02_blue_u_away Scooby Newbie Member#: 99375 Join Date: Oct 2005 Chapter/Region: MWSOC Location: Waterford, MI Vehicle: 2002 Subaru WRX World Rally Blue	Today my BCS ,that i just recently bought, went out on me AGAIN...Took it off, cleaned it, checked the vacuum lines, did all of these tests that are stated above and it checked out okay. But everytime i went back to install it again and reset the ECU, i still couldn't reach target boost. 20 tries later, my battery finally went out on me. Went and bought a new battery, reset ECU, and reconnected the BCS and, "VOILA", boost is BACK..... So, i guess that the battery, for some odd reason, was able to crank my engine up but not enough to power my BCS...how weird....can enyone tell me what i did wrong or did not do completely...because I still do not believe that all i had to do was buy a new battery.