Subaru Outback Forums banner

1 - 20 of 24 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
Hello everyone, I am just about finished putting an engine from an 03 2.5 Manual Outback in a 2001 Outback. Everything has been a direct fit except there is a plug in the wiring harness that has a grey housing and an orange interior that is slightly different than the grey exterior orange interior plug on the engine. Trying to figure out the easiest way to fix this problem. Do I have to swap the whole harness? Can I cut the wires and splice on a different plug etc? Thanks for any help!

PS, first time posting, so if I am posting in the wrong place, wrong way, sorry!
 

·
Registered
Outback 2011 3.6R Premium
Joined
·
1,039 Posts
@plain OM maybe able to help you as he seems to be the wiring guru

Seagrass
 

·
Registered
Joined
·
17,181 Posts
Do I have to swap the whole harness? Can I cut the wires and splice on a different plug etc?
Regret, I don't have an answer. One would have to compare the wiring diagrams to determine where the wires go, and whether or not there's some substantive change between the years that has to be addressed.
 

·
Registered
Outbacks, SVXs, XT6, 4Runner, Celica, Brat, E150s
Joined
·
564 Posts
Need way more information. Where is this plug?

Yes, sometimes the connector will change, but the function is the same, so splicing a new connector onto your harness might be the solution.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #5
Two white plugs are the 2 O2 sensors on the 2001 body from the exhaust.

Two orange plugs are from the main computer each with 4 wires

The one orange connector is from the engine harness and has 4 wires in the shape of an L.

Last photos are of the donor car computer side harness
479469

479471

479467

479465
 

Attachments

·
Registered
Joined
·
11 Posts
Discussion Starter #6
Depending on what order it uploads them it may not be the last two images that are the donor- but obviously the one with the empty engine bay is the donor.
 

·
Registered
2002 Outback
Joined
·
654 Posts
Are you using the intake manifold, wiring harness and sensors from the '03? If so, I would recommend keeping the '01 engine wiring harness and intake/sensors. It should eliminate the problem. I believe there are differences between '01 and '03 with the plug for the AF sensor (front O2 sensor) and the rear sensor may have a different plug too.
 

·
On the Super Mod Squad
2002 Pair: 3.0 VDC Wag & 2.5 Limited Sedan
Joined
·
25,760 Posts
Depending on what order it uploads them it may not be the last two images that are the donor- but obviously the one with the empty engine bay is the donor.

the big change is EGR. 2003 has it, 2001 does not. hence the break down in part #s for the front o2 sensors.

typically people swapping a 2003 backwards into 2000-2002: just put a custom plate over the EGR inlet port on the 2003 engine,...and just run all the 2001 exhaust / sensors / ECU.

if buying o2 sensors: I would buy (and have bought) Densos. as they match subaru specs (cause minor crap problems like wasting gas,...and today Denso maybe the subaru maker)
 

·
Registered
Joined
·
11 Posts
Discussion Starter #9
Unfortunately, I don't have the 01 engine harness or engine, just the 03. But if I was able to get one, would it connect right up to the 03 or would there be different connections on the engine side of things?

I could possibly buy some 01 02 sensors and put those on, but that wouldn't solve the last plug.
 

·
Registered
Joined
·
17,181 Posts
Unfortunately, I don't have the 01 engine harness or engine, just the 03. But if I was able to get one, would it connect right up to the 03 or would there be different connections on the engine side of things?
. . .
Is the 2001 recipient car, manual or automatic transmission?

As was noted in post #7, there might be differences in the exhaust sensor connectors, and the type of connector might depend on whether the car is auto or manual transmission.

According to the wiring diagrams, the 2001 MT engine Front A/F Sensor and Rear O2 Sensor each has four wires, and a square, four-contact connector.

In the 2001 automatic transmission model, while the Rear O2 Sensor also has four wires and uses a four-wire, square connector, the Front A/F Sensor is different; it has six wires, and uses a rectangular, 6-contact connector.

The 2003 FSM does not indicate a difference between MT and auto; both sensors are 4-wire and use a square, 4-contact connector.

I had a further look at the connectors (they're diagrammed in the FSM), and where each wire goes. In the four wire A/F sensors, two wires are for the heater, and two are signal-related. According to the 2001 and 2003 FSM wiring diagrams, the numbering of the contacts in the square A/F Sensor connectors appears to be reversed. Also, in the 2001, power for the heater comes in on connector pin 2, and pin 4 is the ECM heater control. In the 2003, heater power is also on pin 2, but the ECM heater control is pin 3. Moreover, although Pin 2 is used for the same purpose in both, it's not the same pin location in the square connector because of the apparent reversal.

Similarly, in the 2001 MT, the A/F Sensor signal wires (going to the ECM) are pins 1 and 3 of the 4-contact connector; in the 2003, they're 1 and 2 (keeping in mind as well that the connector pin numbering isn't the same).

I've attached the related FSM pages.

I could possibly buy some 01 02 sensors and put those on, but that wouldn't solve the last plug.
Above addresses the first part; which "last plug" does that refer to?
 

Attachments

·
Registered
Joined
·
11 Posts
Discussion Starter #11
Both vehicles are manual. The last plug would refer to the one in the third picture down with the six connecters (but only 4 actual wires) which it seems Eagleeye was saying is the EGR.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #12
Are you using the intake manifold, wiring harness and sensors from the '03? If so, I would recommend keeping the '01 engine wiring harness and intake/sensors. It should eliminate the problem. I believe there are differences between '01 and '03 with the plug for the AF sensor (front O2 sensor) and the rear sensor may have a different plug too.
The engine harness is from the 03 and the main computer harness is from the 01. The recipient car didn't have with an engine, so I don't have the engine harness for that unfortunately. What would you recommend based on that info?
 

·
Registered
Joined
·
17,181 Posts
Both vehicles are manual. The last plug would refer to the one in the third picture down with the six connecters (but only 4 actual wires) which it seems Eagleeye was saying is the EGR.
The diagram for the 2003 attached above includes the EGR, next to the A/F Sensor. It is a rectangular, 6-pin, but appears to have 6 wires, or at least 5 as two are joined.

Note that the connector at the EGR is E18, where the "E" indicates it's part of the Engine Harness. The connectors for the A/F Sensor and the Rear O2 Sensor, in both the 2001 and 2003, are "B", i.e., part of the Bulkhead Harness.

The EGR wiring might not be a concern as the 2001 recipient doesn't have the related connections. (But there might need to be some mechanical mods made as @eagleeye mentioned.)

However, the differences in the wiring connections for the sensors would need to be looked at more closely.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #14
the big change is EGR. 2003 has it, 2001 does not. hence the break down in part #s for the front o2 sensors.

typically people swapping a 2003 backwards into 2000-2002: just put a custom plate over the EGR inlet port on the 2003 engine,...and just run all the 2001 exhaust / sensors / ECU.

if buying o2 sensors: I would buy (and have bought) Densos. as they match subaru specs (cause minor crap problems like wasting gas,...and today Denso maybe the subaru maker)
I'm trying to picture in my mind what such a configuration would look like. This is my first engine swap, so I'm definitely not a seasoned mechanic, especially when it comes to electrical.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #15
So essentially what you all are saying is that both of the orange plugs in the picture with only those two in it (picture 4) and both of the white plugs in picture 5 go to each other for oxygen sensors and then the lone orange plugs in picture 3 is for EGR and does not have a mate in the main harness, but may not need a mate at all since 2001 MT did not have EGR. So if I can cut wires and wire the connectors from the donor engine correctly and then just leave the EGR unconnected, the engine would run and not throw any codes or have major problems?
 

·
Registered
Joined
·
17,181 Posts
what you all are saying is that both of the orange plugs in the picture with only those two in it (picture 4) . . .
I don't have a 2nd generation Outbacks to compare, and from the photos I'm not clear on the connectors shown and which car they are in. In photo 4 (in the text box of the post), the lower connector might be female, and the upper male. In photo 5 (attachment), both appear to be female, so they can't go to each other.

Also, as noted earlier, although both years use 4-pin connectors, it seems the wiring to them is different. I think this would need tracing to identify the wires going back to the ECM and the ones coming from the sensors, to be sure that the four wires from the sensors will be connected to the correct circuits of the ECM when the connectors are attached.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #17
I don't have a 2nd generation Outbacks to compare, and from the photos I'm not clear on the connectors shown and which car they are in. In photo 4 (in the text box of the post), the lower connector might be female, and the upper male. In photo 5 (attachment), both appear to be female, so they can't go to each other.

Also, as noted earlier, although both years use 4-pin connectors, it seems the wiring to them is different. I think this would need tracing to identify the wires going back to the ECM and the ones coming from the sensors, to be sure that the four wires from the sensors will be connected to the correct circuits of the ECM when the connectors are attached.
Ok, thanks for that. So even though I'd have to tear apart the whole dash, do you think my better option is tearing out all the main wiring and computer from the 2003 and putting it in the 2001? It seems like a bear to do, but especially if there would always be a code with the EGR not plugged in, I suppose it may be worth it.
 

·
On the Super Mod Squad
2002 Pair: 3.0 VDC Wag & 2.5 Limited Sedan
Joined
·
25,760 Posts
I'm trying to picture in my mind what such a configuration would look like. This is my first engine swap, so I'm definitely not a seasoned mechanic, especially when it comes to electrical.
pipe for EGR runs off the cat area and back up into one of the heads.
the removed pipe should look something like this, (credit to Ebay poster for a 2003 type)

so there should be a hole tapped out in one of the heads for the EGR inlet. this needs a slice of aluminum about the size of a credit card stuck over it to seal it up on 2003 types dropping into 2001 types.
( seen bought ones shaped like a rhombus or a parallelogram in parts catalogs)

and I guess a 2003 ERG outlet should have a plug stuffed into it to stop the stinky gases from just venting (or causing codes).

incidentally: the 2001 legacy outback manual trans engine is called a EJ252. in 2003 they eliminated that number and just used the EJ251 as the # for both auto and manual equipped. (just to confuse matters)

 

·
Registered
Joined
·
17,181 Posts
So even though I'd have to tear apart the whole dash, do you think my better option is tearing out all the main wiring and computer from the 2003 and putting it in the 2001? It seems like a bear to do, but especially if there would always be a code with the EGR not plugged in, I suppose it may be worth it.
I think you're right -- it would be a bear. Also, there might be other functions that are different, and the 2003 Bulkhead harness and Engine Control Module might not be happy campers in the 2001.

But let's back up a bit, because I'm not sure of the context.

The 2001 recipient doesn't have an engine, or Engine Harness. But the rest of the wiring coming into or in the engine area is there, right?

If so, we know that in the 2001, the Front A/F Sensor plugs into connector B18, which is part of the [existing?] Bulkhead Harness.

Similarly, the Rear O2 Sensor plugs into [existing?] connector T6, which a harness that goes up over the transmission and connects via T6 to B19, yet another connector that's part of the [existing?] Bulkhead Harness.

So in both cases, if the two related harnesses are there, the questions that remain are:

1) Which sensors are you using; the originals in the 2001, or the ones from the 2003?

2) Do the connectors on the sensors match and physically connect properly (i.e., mechanically) with connectors B18 and T6?

3) Do the four wires of the each sensor connect to wires in the harnesses that go to the right terminals at the ECM? Or would they have to be shifted around in one of the mating connectors to correct, but this is a lot simpler than replacing the whole Bulkhead Harness.)

If, in fact, you're using the 2001 sensors, or new ones that are for the 2001, and not the ones used in the 2003, I don't think there's a problem. They should plug into the related harness connectors and work. It only becomes a problem if the 2003 sensors are being used, where, although they all use 4-wire connectors, it appears that wiring layout is different. (According to Products | Oxygen & A/F Sensors | Oxygen Sensors, different sensors are used in the two years, and based on the wriing diagrams, they might not be interchangeable.) I might just spring for two new 2001 sensors and be done.

If that moves the sensor issue along, I'm beginning to wonder if the Engine Harness on the 2003 engine donor is fully compatible with the existing wiring in the 2001. Is it only the addition of the 2003's EGR wiring, which goes to E1 and B20 (in the 2003 wiring diagram), and which might not exist in the 2001 2.5 existing wiring (in which case, they can be disregarded.)

That leaves me with one more question: If the 2003 large Engine Harness connector fit to the corresponding large Bulkhead Harness connector, to all the wires in the Engine Harness go to the same places on the engine as did the 2001 Engine Harness. In other words, we wouldn't want the trigger signal wires for the injectors to be going to elsewhere. If Subaru changed the wiring layout for the two exhaust sensors between years, this isn't an impossible situation.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #20
So to answer question 1, the sensors are both from the 03 and not from the 01, which I don't have. But it does seem like it would be much simpler to get 01 sensors. I'd probably have to find some used ones as they would be a little pricey for this project new, but that is a good possibility. Seems like the proper connection would only be on the manual, not the automatic, right?

In terms of the EGR, should the plate be aluminum or steel? I would probably have to make a gasket for it as well? For the plugs, just find the right sizes bolts and stick them in?

Thank you so much for your time you've invested in helping me. It has been an immense blessing.
 
1 - 20 of 24 Posts
Top