55 replies to this topic

[pamike]

been having this problem for a while now and i'm really getting tired of this. theirs some details of my problem here
http://www.ultimates...ad.php?t=117124
anyway, i noticed a very faint humm when listening around the top of the motor and i found if i unplug the iac valve, it stops. and if i plug it back in it humms again. while doing this the battery volts goes from 12v down to 11.95v and back up when i unplug it again. so it seems to me that somthing is on that shouldn't be. now my question is should i have any power to the iac valve connector with the key off? i'm getting 11.5 volts at the connector on the left and middle wires when looking at the connector. after messing with it for about a half hour i checked the volts at the iac connector and got barely nothing. then after turning the key on and back off i got 11.5 again at the connector.
so is this normal for this to have power for a while after the car is turned off?

Edited by pamike, 18 April 2012 - 04:55 PM.

[Cougar]

Disconnect the wires on the back side of the alternator and then see if there is still voltage getting to the IAC valve. If the voltage is now gone then replace the alternator, it has a diode problem.

[Rooster2]

Same thought before reading Cougar's response. I too, think your alternator is bad.

[pamike]

ok i'll see if i can get it to do it again and try that. but i do have to say that the alt has been replaced with a good used unit in the time that the car has been doing this and it still goes dead. i guess the chances of it being the alt are slim but i'll check into it.

i do have one question though. the only wiring diagram i have is in my haynes manual. it shows a fusable link (i think this is the one in the under hood fuse box) then a relay, then it goes to various engine sensors. so is it possable it could be a relay thats sticking and not cutting power when car is off? i didn't see this relay but it would be nice to have a good wiring diagram. i don't really know how accurate the haynes manual is.

[pamike]

first off, i disconnected the alt and it did nothing. so this is not the problem.

i started pulling fuses in the under hood box. when i pulled this green 30 amp one the power at the iac went away so i'm assuming this is the circuit i want. here is a pic of it



in the center of the pic it's the big green fuse. there are 2 of them. one on the right is the one i'm talking about. the fuse box cover has it listed as 30a SBF NO 2. my haynes manual shows this going through a relay labeled main relay to the center wire of the iac connector. so where is this main relay located?
and it looks as if the relay is powered by the ecu (mpfi control unit in the haynes manual) so it would almost have to be a bad sticking relay or somthing is wrong with the ecu and its powering the relay when it shouldn't be. so i think i really need to find this relay.

Edited by pamike, 19 April 2012 - 04:53 PM.

[Cougar]

Very good troubleshooting Pamike. The Main Relay should be under the dash on the far left side near the top. Look for a brown 6 pin socket the relay plugs into.

[pamike]

i found the relay. it was a pita to get to. had to move alot of stuff around under the dash to get to it. so where do i get one of these?

[grossgary]

nice work, can you google the part number on the relay?

if it's a common relay you might even find it on amazon or ebay, subaru uses relays common to other models sometimes.

[pamike]

well the advance auto web site shows 2 that look to be right. one is $17 BWD #R802 and the other $60:eek: BWD #R6193. so whats the difference? anyway they don't show any in stock so i might go to the local junk yard for a used one. i'm not looking forward to digging under the dash to get to it again.

[pamike]

well i swaped the relay out and the problem is still there. now i'm stumped. for some reason the circuit stays connected until i pull the fuse from the box under the hood. but whats wierd is i can replace the fuse and all is good.

[AKghandi]

that should help you this guy has many many helpful vids.

[Cougar]

Since it appears the Main Relay is being turned on when it shouldn't be check to see if the fuses in the dash panel have voltage getting to them while the ignition switch is OFF. If there some getting power then you might need to replace the switch.

[pamike]

well what i did was check the signal wires that turn the relay on and off and i got voltage with key on and nothing with key off. so thats why this makes no sense to me. but if the relay was being powered up with the key off then when i pulled the fuse in the circuit and then replaced it, shouldn't it turn right back on? thats not whats happening, after i pull the fuse to cut the power in that circuit then replace it nothing turns back on until i turn the key back on. so what could keep the relay turned on?

[Cougar]

The Main Relay is controlled by the ECU I believe so it may have a fault inside it. Something inside it isn't turning off until power is disconnected and resets things.

Edited by Cougar, 26 April 2012 - 09:45 PM.

[pamike]

as i said i did pull the relay and check the 2 wires that trigger the relay for power. they didn't have power with key off. and when i pull the fuse it's the fuse for the circuit that the relay turns on. the fuse is not in the circuit with the ecu. so if it was the ecu keeping things powered up, wouldn't me putting the fuse back in reconnect the circuit and turn everything back on? it doesn't. so what i'm seeing is the relay staying connected even with the ecu side of it turned off:confused:. but i guess i can try another ecu if i can get ahold of one. where is it located?

[Cougar]

By disconnecting the relay before checking the power to the coil windings you may have changed things. Please let me know if fuses 1, 8, and 15 in the dash panel have voltage getting to them while the trouble is happening. Don't remove the relay. If there is voltage getting to them then there may be a problem with the ignition switch. The trouble may also be something is crossing the fused circuits in the dash fuse panel.

Edited by Cougar, 27 April 2012 - 03:28 PM.

[pamike]

ok, those fuses have no power. but i did manage to unplug the relay just enough to get my test leads into the terminals while the relay was still pluged in and i am getting power to the relay with key off until i break the circuit. from what i see this is triggered through the ecu.

[Cougar]

You are correct about the ECU triggering the relay. Check to see if any of the other fuses in the dash have power getting to them while the trouble happens. Perhaps there is another path bridging power to a place it shouldn't be. I tend to think though replacing the ECU is going to be needed. There are a couple of wires tied to the ECU that are connected to the relay contacts. One of those may be where the trouble is at. If you pulled one at a time to see if that stops the problem it would prove that the ECU is the problem.

[pamike]

where is the ecu located? is it under the right side front carpet like my wrx is?

[pamike]

well i pulled the ecu. i'll find out soon enough if it's the problem. i'm going to pull the ecu out of my brothers legacy and try it so i'll see what happens. his happens to be the same year so should be no issues with swaping them.

i did come across this thread on here that says the 96 used a few different ecu part numbers. these are listed as a few. mine happens to be last 3 digits 270. whats the difference? are they interchangable? i know my brothers car is currently running a 95 2.2 with the stock 96 2.5 computer with no problems.

22611AC271
22611AC431
22611AC910
22611AC930

[ivans imports]

the ing system powers the idle moter for about one min after shutoff makes a buzz it times out but thiss is normal operation as far as i know all ejs do thiss somthing to do with reseting the idle moter

[pamike]

my brothers doesn't do this. i checked for power after key was off and got nothing. mine will stay powered on until it runs the battery dead. the relay doesn't turn off until i cut the power.

anyway the ecu is not the problem. i swaped out my brothers and it still was doing it. the relay wire goes to the ecu so it has to be somthing telling the ecu to do it:confused:

[forester2002s]

I'm not sure if I can really help, since I've never experienced this problem.

All that comes to mind, is that so many weird electrical problems are eventually found to be due to a bad ground somewhere in the system.

Just a thought.

[Gloyale]

my brothers doesn't do this. i checked for power after key was off and got nothing. mine will stay powered on until it runs the battery dead. the relay doesn't turn off until i cut the power.

anyway the ecu is not the problem. i swaped out my brothers and it still was doing it. the relay wire goes to the ecu so it has to be somthing telling the ecu to do it:confused:

Is there a diode on the switched power TO the ECU?


edit.
looked and nope, no diode.

hmm......you did try another relay?


Try this:

using a voltmeter (not just a light) test for any voltage between the Black wire and another ground location. If there is any voltage at all, that could be a problem. When the voltage drops off the green wire (ECU off) if there is a few volts on the ground wire the coil may be staying engaged, grounding through the ECU.

just a possibility?

Edited by Gloyale, 28 April 2012 - 01:52 PM.

[pamike]

Is there a diode on the switched power TO the ECU?


edit.
looked and nope, no diode.

hmm......you did try another relay?


Try this:

using a voltmeter (not just a light) test for any voltage between the Black wire and another ground location. If there is any voltage at all, that could be a problem. When the voltage drops off the green wire (ECU off) if there is a few volts on the ground wire the coil may be staying engaged, grounding through the ECU.

just a possibility?

yup i put in another relay, that was the first thing i did. i checked with a volt meter at the relay and i'm getting power through the green and black wires. this is why the relay is on. but whats odd is if i pull the fuse for the circuit that the relay controls, it turns off the relay. this shouldn't have anything to do with the green/black wires should it? and after replacing the fuse it's off until the key is turned on again