Parasitic current drain ECU, EJ22 1992

[pvfahrer]

Hi,

first off, its my first post here, so please be kind if i am in the wrong category. My name is Andi, i have a VW Vanagon with an 1992 EJ22 most likely put of a legacy. I bought the VW with the conversion done by the PO and had to iron out some kinks in the beginning, now the car is running nicely. However, the battery (new) is getting drained when i leave the car in the street for a week. I have checked and the battery is getting charged by the alternator, so went and tested for parasitic current draw, and i found that there are about 200mA (0.2A) of parasitic draw. Reading up indicated that this is about 10 times higher than what is usually accepted as okay. So i went ahead and checked sources for the drain, I was able to figure out that when i pull the fuse for the ECU, the drain drops to 2mA, which is from the clock and the radio code. So th ECU itself draws the majorty of the current, i wen ahead and disconnected the alternator and the relays that are connected to the ECU, non of these had any impact on the parasitic drain. I am considering to try out a different ECU to make sure it is not just some weird defect to if (i read the rarely brake) but it would still be an easy test.   

So i am coming to my actual question, can somebody tell me what ECU is compatible with mine.

The one that is in the car is a F9 22611 AA930 A18-000 RF6

I found one in the bay that seems to be very close but i wonder if it really is compatible: F9 22611 AA931F JA18-000 RK3

 

Alternatively, maybe somebody here has a functional compatible ECU lying around and would be willing to loan this to me, i would ofcourse cover the shipping and either way whether i keep it or return it, come up with a compensation. 

[Numbchux]

Any first gen non-turbo Legacy ECU should work.

 

Although, I HIGHLY doubt it is the ECU itself. More likely something in the wiring, as the power circuit all has to be modified when doing a swap.

My first thought, is the ignition coil. In the Legacy, this power wire comes straight off the ignition switch and that wire has to be tied into a new power source (I remember it, as I missed it a couple times...), if the person who prepped the harness tied that into an unswitched power source, that would cause a considerable drain.

 

I'd grab a test light and/or multimeter and start testing power wires at the coil, ignitor, fuel injectors, etc. with the key off. 

[Rampage]

4 hours ago, pvfahrer said:

I was able to figure out that when i pull the fuse for the ECU, the drain drops to 2mA,

Is this using the fuse holders from the 92 Legacy? If so, is it fuse 16 (15AMP) that you are pulling?

That fuse feeds 12v to Pin 12 (Yellow wire) of connector B58 (ECU 12 pin connector) ONLY with the Key ON and START positions. If it is hot all the time move the source of the fuse to the IGN wire from the IGN SW.

There are 2 other pins on the ECU connector B48 (22 pin connector) Pins 2 and 13 (Yellow/Red stripe) that get voltage from the IGN Relay contacts and the coil of the relay is triggered by the ECU and then kept closed with power through a diode from the alternator when the alternator is charging. Those two pins should be dead with the IGN key OFF.

In case you don't know, when looking at the wiring diagrams in the FSM the connector plugs are shown looking at the pin side and numbered left to right. Looking at the wire side of the connectors it is the same row but the pin numbers are backwards right to left.

[pvfahrer]

21 hours ago, Numbchux said:

Any first gen non-turbo Legacy ECU should work.

 

Although, I HIGHLY doubt it is the ECU itself. More likely something in the wiring, as the power circuit all has to be modified when doing a swap.

My first thought, is the ignition coil. In the Legacy, this power wire comes straight off the ignition switch and that wire has to be tied into a new power source (I remember it, as I missed it a couple times...), if the person who prepped the harness tied that into an unswitched power source, that would cause a considerable drain.

 

I'd grab a test light and/or multimeter and start testing power wires at the coil, ignitor, fuel injectors, etc. with the key off. 

 

16 hours ago, Rampage said:

Is this using the fuse holders from the 92 Legacy? If so, is it fuse 16 (15AMP) that you are pulling?

That fuse feeds 12v to Pin 12 (Yellow wire) of connector B58 (ECU 12 pin connector) ONLY with the Key ON and START positions. If it is hot all the time move the source of the fuse to the IGN wire from the IGN SW.

There are 2 other pins on the ECU connector B48 (22 pin connector) Pins 2 and 13 (Yellow/Red stripe) that get voltage from the IGN Relay contacts and the coil of the relay is triggered by the ECU and then kept closed with power through a diode from the alternator when the alternator is charging. Those two pins should be dead with the IGN key OFF.

In case you don't know, when looking at the wiring diagrams in the FSM the connector plugs are shown looking at the pin side and numbered left to right. Looking at the wire side of the connectors it is the same row but the pin numbers are backwards right to left.

Thanks folks! i will look into all these suggestions, the fuse that i am pulling is an additional in-line fuse in the conversion wiring loom, i will check what pin the 12V input is connected to and if it is hot all the time, but i am almost certain that it is. What pin is the main power-in supposed to go to? 

I have already looked into voltage output on a few sensors in off position, i found that the VSS, the inhibitor switch and parking break indicator light all show 5V when ignition is on or off, i believe this should not be the case.

However the current draw is 0.2A when ignition is off and 3A when on (engine not running), so i guess the ignition relay or at least parts of that circuit work properly.  

[Rampage]

Check pin 12 on the 12 pin connector. Does in have voltage and does it go away when you pull that fuse you mentioned.

The VSS is wired into the Transmission Control Unit on auto transmissions. Is this a 4EAT? Check what I posted here. There is a pic of the TCU connectors.

 https://www.ultimatesubaru.org/forum/topic/171518-1990-legacy-fwd-automatic-transmission-problem/

 

You can get the 92 FSM wiring diagrams here. http://jdmfsm.info/Auto/Japan/

I also found this. They fit 8 different models in 92.

Engine Control Module

Part Number: 22611AA933
Supersession(s): 22611AA930; 22611AA931; 22611AA932

I found this on one Subaru site for the 22611AA930. Production Date: 199105 - 199204

I looked up a 92 Legacy at subarupartsdepot.com and found this.

• SKU:22611AA933
• Other Names: EGI Control Unit
• Description: Legacy. Without turbo, manual trans

[pvfahrer]

On 9/25/2020 at 2:27 PM, Rampage said:

Check pin 12 on the 12 pin connector. Does in have voltage and does it go away when you pull that fuse you mentioned.

The VSS is wired into the Transmission Control Unit on auto transmissions. Is this a 4EAT? Check what I posted here. There is a pic of the TCU connectors.

 https://www.ultimatesubaru.org/forum/topic/171518-1990-legacy-fwd-automatic-transmission-problem/

 

You can get the 92 FSM wiring diagrams here. http://jdmfsm.info/Auto/Japan/

I also found this. They fit 8 different models in 92.

Engine Control Module

Part Number: 22611AA933
Supersession(s): 22611AA930; 22611AA931; 22611AA932

I found this on one Subaru site for the 22611AA930. Production Date: 199105 - 199204

I looked up a 92 Legacy at subarupartsdepot.com and found this.

• SKU:22611AA933
• Other Names: EGI Control Unit
• Description: Legacy. Without turbo, manual trans

thanks for the info on the ECU, unfortunate somebody bought it of the bay before i could act... 

I am using the Volkswagen automatic transmission so i don't use the TCU, going to check the pins later this week!

 

[pvfahrer]

On 9/24/2020 at 7:43 PM, Rampage said:

Is this using the fuse holders from the 92 Legacy? If so, is it fuse 16 (15AMP) that you are pulling?

That fuse feeds 12v to Pin 12 (Yellow wire) of connector B58 (ECU 12 pin connector) ONLY with the Key ON and START positions. If it is hot all the time move the source of the fuse to the IGN wire from the IGN SW.

There are 2 other pins on the ECU connector B48 (22 pin connector) Pins 2 and 13 (Yellow/Red stripe) that get voltage from the IGN Relay contacts and the coil of the relay is triggered by the ECU and then kept closed with power through a diode from the alternator when the alternator is charging. Those two pins should be dead with the IGN key OFF.

In case you don't know, when looking at the wiring diagrams in the FSM the connector plugs are shown looking at the pin side and numbered left to right. Looking at the wire side of the connectors it is the same row but the pin numbers are backwards right to left.

So this took me a lot longer to look into this than expected... but I guess that’s just life. 

I have checked pins 2 and 13 on b48, they are hot with the ignition off, so are the injectors and a few other sensors. If I pull that 30a fuse the pins are cold. So I followed the cables on the fuse and found that one side is connected to the alternator 12v pole and the other end connects 12v input at the ignition relay/ fuel pump replay as in the wiring loom. So then I thought that maybe the Relais is fried, but the pins stay hot when I pull the Relais. So this means that either the wiring of the relay is wrong, or there is something else wrong with the ignition in signal or the shut off signal to the ecu. I am puzzled.. 

 

[GeneralDisorder]

The ECU doesn't control the ignition relay - that is controlled by the ignition switch. Fuel pump relay is controlled by the ECU.

The ECU is not your problem. It can't draw enough power to kill the battery on it's own. Whoever did the swap has wired it wrong. 

GD

[idosubaru]

On 9/24/2020 at 2:04 PM, pvfahrer said:

H, I was able to figure out that when i pull the fuse for the ECU, the drain drops to 2mA, which is from the clock and the radio code. 

Radio or clock is your issue.

If the drain is inconsistent for some reason, testing may not be fool proof. How sure are you that the drain is always existent?

1. Disconnect those and anything else on that circuit, except the ECU, and check for drain. What do you get?

2. Disconnect everything including the ECU on that fuse circuit - what do you get?   Being custom wiring I’m wondering if there’s something on there that you don’t know about. 
Maybe the ECU power wire is shared with something else you’re not aware of?
 

Edited January 3, 2021 by idosubaru

[pvfahrer]

I am almost certain it is something in the ignition switch circuit that activates the ignition relay. I tested the drain over night and it did'nt change.

If i pull the 30A fuse (SBF-2) the current drain disappears and the 12V on A2, A13 and the injectors disappears, with the fuse they are hot regardless of the ignition switch position.

I have to hunt down Fuse no.16 and how the ignition switch is wired into the loom, it must be connected since parts of the ECU function (test connecters connected) do only work when the ignition is ON.

What would happen if that diode after fuse no 16 is dead? could this lead to a malfunction of the ignition relay? 

Edited January 3, 2021 by pvfahrer

[Rampage]

5 hours ago, pvfahrer said:

I have checked pins 2 and 13 on b48, they are hot with the ignition off, so are the injectors and a few other sensors. If I pull that 30a fuse the pins are cold. So I followed the cables on the fuse and found that one side is connected to the alternator 12v pole and the other end connects 12v input at the ignition relay/ fuel pump replay as in the wiring loom. So then I thought that maybe the Relais is fried, but the pins stay hot when I pull the Relais. So this means that either the wiring of the relay is wrong, or there is something else wrong with the ignition in signal or the shut off signal to the ecu. I am puzzled.. 

The injectors will always be hot from the 30 amp fuse.

If the voltage goes away from B48 pins 2 and 13 when you pull the 30 amp fuse, but not when you pull the relay, then it sounds like they are wired to the fuse output wire instead of the relay contacts.

 

55 minutes ago, pvfahrer said:

What would happen if that diode after fuse no 16 is dead? could this lead to a malfunction of the ignition relay? 

If the diode is open the ignition relay will not operate. With the Key ON, Fuse 16 supplies voltage through the diode to the coil in the ignition relay and the other end of the coil is grounded, so it will close the contacts.

If the diode is shorted the relay will still work.

[1 Lucky Texan]

does this car have an upgraded headunit? CD player? maybe a CD is stuck in it.....or an external amp is on.....

 

just a wag.

[pvfahrer]

18 hours ago, Rampage said:

The injectors will always be hot from the 30 amp fuse.

If the voltage goes away from B48 pins 2 and 13 when you pull the 30 amp fuse, but not when you pull the relay, then it sounds like they are wired to the fuse output wire instead of the relay contacts.

 

If the diode is open the ignition relay will not operate. With the Key ON, Fuse 16 supplies voltage through the diode to the coil in the ignition relay and the other end of the coil is grounded, so it will close the contacts.

If the diode is shorted the relay will still work.

thanks for clarifying, i double checked and the pins 2 and 13 on B48 are hot with the relay pulled, actually the car starts without the relay with the CEL on and rough idle, i didn't read out the error code though.

So here is how the PO wired the relays. On the left hand side is the dodgy cable connecter he used. He spliced together the two yellow cables from the ignition relay, the yellow one from the fuel pump, two yellow/red cables (unknown to me) and connected them all with the black cable (new) that goes through a 30A fuse onto the hot pin on the alternator. As far as i can decipher the wiring diagram this is all correct, only the two yellow/red wires don't make sense to me...any ideas?

  

 

[Rampage]

I wish I could get my hands on it to sort it out.

It looks like he used a red wire nut to connect all those wires together.

Remove the tape and unscrew wire nut. Put it back on the Black (hot) wire OR pull the 30 amp fuse.

To play it safe check for voltage on the removed wires. They should all be dead.

Check for continuity from each of the wires (probably Red/Y) to pins 2 and 13. Mark the one for pins 2 and 13.

Scroll up and look at the wiring diagram you posted. The wires from the fuse to the relay are Yellow. The wires out of the relay are Yellow/Red.

If the continuity check says one of those wires goes to pins 2 and 13 it must be moved to the output of the relay, or add another relay to power it.

With the fuse in I would check amperage draw on each of those wires one at a time from the black wire with an amp meter.

[pvfahrer]

11 hours ago, Rampage said:

I wish I could get my hands on it to sort it out.

It looks like he used a red wire nut to connect all those wires together.

Remove the tape and unscrew wire nut. Put it back on the Black (hot) wire OR pull the 30 amp fuse.

To play it safe check for voltage on the removed wires. They should all be dead.

Check for continuity from each of the wires (probably Red/Y) to pins 2 and 13. Mark the one for pins 2 and 13.

Scroll up and look at the wiring diagram you posted. The wires from the fuse to the relay are Yellow. The wires out of the relay are Yellow/Red.

If the continuity check says one of those wires goes to pins 2 and 13 it must be moved to the output of the relay, or add another relay to power it.

With the fuse in I would check amperage draw on each of those wires one at a time from the black wire with an amp meter.

sounds like the next thing to do, i can already see that the red/y wires in the wire nut are not directly going into relay and the wire gauge also doesn't match the wires on the Pin 2 and 13, so they must be going/coming from somewhere else.. i will investigate and report back. 

 

 

 

[pvfahrer]

16 hours ago, Rampage said:

I wish I could get my hands on it to sort it out.

It looks like he used a red wire nut to connect all those wires together.

Remove the tape and unscrew wire nut. Put it back on the Black (hot) wire OR pull the 30 amp fuse.

To play it safe check for voltage on the removed wires. They should all be dead.

Check for continuity from each of the wires (probably Red/Y) to pins 2 and 13. Mark the one for pins 2 and 13.

Scroll up and look at the wiring diagram you posted. The wires from the fuse to the relay are Yellow. The wires out of the relay are Yellow/Red.

If the continuity check says one of those wires goes to pins 2 and 13 it must be moved to the output of the relay, or add another relay to power it.

With the fuse in I would check amperage draw on each of those wires one at a time from the black wire with an amp meter.

victory!!! I did as you said and looked into the wire nut and as mentioned there were two additional yellow/red wire in there. i took them out and connected the rest, now everything checks out as supposed to, no 12V on 2 or 13 when ignition off and hot when ignition on, engine does not start without the ignition relay as supposed. The two y/r cable are cold when off and have 12 when engine is running, i found  continuity to the red/yellow wires art the o2 sensor, so i am assuming that the lambda probe and probably a few other things did draw current when ignition was off. The parasitic current draw dropped now from 200mA to 7mA when ignition is off... I hope this should address the issue! Thanks for all the help especially to Rampage, now i have to figure our why the engine sucks 1qt of oil every 1000mls (100k mils ej22 92)...details.

 

 

Edited January 4, 2021 by pvfahrer

[idosubaru]

16 hours ago, Rampage said:

I wish I could get my hands on it to sort it out.

It looks like he used a red wire nut to connect all those wires together.

Remove the tape and unscrew wire nut...

That’s amazing.  Well done man!

[idosubaru]

11 minutes ago, pvfahrer said:

victory!!! I did as you said and looked into the wire nut and as mentioned there were two additional yellow/red wire

now i have to figure our why the engine sucks 1qt of oil every 1000mls (100k mils ej22 92)..

 

that’s great!  That’s crazy y’all figured out a custom wiring issue.  Nuts. 

EJs loose oil past the oil control piston rings. There really isn’t any other way those consistently loose oil internally. 

You can check valve stem seals but that’s almost beyond unlikely for that engine.

[pvfahrer]

20 minutes ago, idosubaru said:

 

that’s great!  That’s crazy y’all figured out a custom wiring issue.  Nuts. 

EJs loose oil past the oil control piston rings. There really isn’t any other way those consistently loose oil internally. 

You can check valve stem seals but that’s almost beyond unlikely for that engine.

yeah i did a compression test and got some uneven numbers 130-180 which went up to 180±10 when i did the wet test, guess its time for a rebuild on that one, although it still runs fine as long as i keep putting oil in

 

[Rampage]

33 minutes ago, idosubaru said:

That’s amazing.  Well done man!

Thanks.

What really helped was that last picture with the wire nut. Made me think the PO bypassed the ign. relay, which he did.

I have wired many vehicles from scratch over the years mostly old ones. The ones I liked doing for friends are a GTO from the drag strip back to the street, a 37 PT50 and a 52 Ford pickup. Sometime this year I will wire a 32 Ford pickup, 460 w/blower and 2 4's for the street.

[Rampage]

1 hour ago, pvfahrer said:

victory!!!

Makes you feel great huh. All that tension gone.

1 hour ago, pvfahrer said:

1qt of oil every 1000mls

That is really not that bad for an old engine. What oil do you use in it? The next time it is down a quart put in a quart of Lucas Motor oil treatment. I use it in our 95  and 97 EJ22's.

[idosubaru]

20 hours ago, pvfahrer said:

vnow i have to figure our why the engine sucks 1qt of oil every 1000mls (100k mils ej22 92)...details.

Replace the PCV valve, use Subaru OEM.

[pvfahrer]

1 hour ago, idosubaru said:

Replace the PCV valve, use Subaru OEM.

just read up on this a little bit, this would also explain why it leaks semetimes from the rear main seal...I will look into he pcv valve and replace it!

[pvfahrer]

19 hours ago, Rampage said:

Makes you feel great huh. All that tension gone.

That is really not that bad for an old engine. What oil do you use in it? The next time it is down a quart put in a quart of Lucas Motor oil treatment. I use it in our 95  and 97 EJ22's.

yeah its a good reward to figure things out with guidance and see the effect of them! its even better if you sort them out yourself, but with this stuff expert advice is priceless and saves a lot of time!

Do you mean this Lucas stuff here?

[Rampage]

This one. Part# 10001. Substitute one quart of oil when changing oil and filter.

I also use 10W30 regular or a synthetic blend oil. Never full synthetic in a high mileage engine.

Good thing @idosubaru mentioned PCV valve. I change them when doing other stuff on the engine. And the molded rubber hose that connects to it gets hard and will crack.