OB99W
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Posts posted by OB99W
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Of course I've been looking at all the non turbo stuff.
There are just too many model variations.
That's why he is the Master! AND Commander!
I'd like a demotion! Otherwise, expectations are too high and I might not be able to live up to them...
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wow great detective work! this afternoon after work, i am going to get the car running and up to temperature, then do a voltage and ground check. Thanks for all the help so far! i will post up later how my checks turn out!
You're welcome. We'll see how this goes after you post test results.
coming off the main relay for the o2 system, there is a BR wire that goes to pin E10 (seen on page wi-84, section 17) what should i be reading at that pin? 12V correct?Yes, that BR (black/red) wire is powered from the battery, via a slow-blow fuse (SBF-5), and should have 12 volts on it.
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I looked around some more, and found ECU info here:
http://www.northursalia.com/modifications/misc/wiring/wiring.html
From the above site, '02/'03 WRX ECU pinout:
http://www.northursalia.com/modifications/misc/wiring/wrxpin.html
Also from that site, '04 WRX ECU pinout:
http://www.northursalia.com/modifications/misc/wiring/04_DOHC_ECU.pdf
For some reason best known to Subaru, they apparently changed (possibly in error) the numbering of some of the ECU connectors. It seems they are equivalent as follows:
02/03--04
B134--B134
B135--B135
B136--B137
B137--B84
B84---B136
Assuming the ECU info at NorthUrsalia is correct, and taking into account the connector numbering switch, a random check of several connections revealed no differences between the '02/'03 and the '04 ECU pinout.
Specifically for the A/F sensor, both signal and heater, the pin numbers are shown as the same whether for B137 on the '02/'03 info or B84 on the '04.
The ground distribution info for the '04 turbo ECU shows pins #8 & #9 (black/blue) as ground in the connector that the A/F sensor goes to. I'd suggest checking the voltage at those pins relative to a good chassis ground when doing the other measurements. The voltage there should be very low if there isn't excessive resistance in connectors, etc.
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I found an FSM for 03 Forester. Not sure how close that is but it's deffinitely different than the 05 Impreza and Legacy ones I have. [...]
I've got the 03 Forester info already. Foresters are built on the Impreza chassis, so they're similar.
However, the WRX is a turbo (2.0L DOHC), and in that respect they're not the same as the base models, and the ECU is different as well.
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so looking at the diagrams you provided, if you look under section 17 "engine electrical system" the very first diagram shows the o2 sensor circuit. there it is saying that the signal wires are e19 and e29 the shield is e18 and the two white wires are e4 and e5. the "e" connector on this drawing is b84.
Yes, I'm aware of that -- what I'd like to know is whether B134 and the other ECU connectors (including B84) shown on page WI-82 (page 3 of the PDF) match your actual ECU (since you said that the B134 diagram I previously posted didn't match).
Also, you had previously said that your A/F sensor wiring was to B137. Is that correct, or does it go to what's referred to as B84?
i won't get to try the latest suggestions until tomorrow night as the car isn't at my house.The 3.4V was when the engine was cold, ignition was on/engine off taken from the sensor's plug while the sensor was unplugged.
The 12V was taken when engine cold, ignition on/engine off taken from the back of the ecu plug (still plugged in) and also taken from the sensors plug while it was plugged in.
I didn't realize that the 3.4 volt reading was taken with the sensor unplugged. I'd suggest the first thing to check is that the white wires you're measuring at the ECU are indeed connected to the A/F sensor. Next, with engine warm and idling, check the voltage on the white wire(s) again, with everything plugged in.
i did notice one more thing, the shield (pin e18) is connected to the ecu via a yellow wire, on the engine side it stops 6" before the plug and isn't connected to anything.The shield should only be connected at the ECU end. Otherwise, it will form a ground loop and likely induce noise rather than shield it.
I really appreciate all the help, my brain is mush trying to figure this out. let me know if you need anything else clarified.I'm glad to help, and hopefully we'll figure this out. I can understand the "mush" comment. Even though much of my time is spent doing this sort of thing, it still can prove challenging at times.
If anyone has a link to a 2003 WRX engine wiring diagram, it would be helpful to be able to compare it to the 2004.
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ok, so the 2 white wires are reading 12v at the ecu when everything is hooked up and ignition on. there is no change when i rattle the connectors.
If you were connected to the heavy white wire at the ECU that's going to the A/F sensor heater, it should have read about what you got at the sensor before, about 3.4 volts.
Did you have the engine warmed and idling when you got the 3.4 volt reading?
Did you have the engine warm and idling when you got the 12 volt reading?
Could you check the voltage at the white wires at both the sensor and ECU, engine warm and idling, in order to verify that they're the same? Or, unplug the connector at the sensor and the one you're measuring at the ECU, and check resistance between them to make sure you're on the same wiring.
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neither my b137 nor b134 connector look like that
I didn't expect the B137 to look like it -- only the B134 might have.
The harness came out of a 2004 wrx (non sti)i can't upload attachments, maybe i need to have a certain number of posts first?
Please download the following:
It has diagrams for the 2004 Turbo, SOHC, and STi -- the Turbo is first. See if the ECU connectors match what you have. Let us know.
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my 05 manual says that wires 2&3 in b134 are yellow and yellow with blue...
That should depend on turbo versus non-turbo, etc. -- they vary.
my two heavy gauge white wires are in b137 pins 4&5. If i recall correctly all the o2 sensor wires are in b137So far, I can't find a diagram that matches.
1) Does your B134 ECU connector outline match the diagram I posted?
2) What exact model did the 2004 harness come from -- was it an STi?
3) Can you post a diagram of your B137 (similar to the B134 one I posted)?
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Welcome to the forum.
Since you didn't mention it, I'll assume that the Check Engine light isn't illuminated (if it is, let us know). One possible cause of the problem you're experiencing is a defective ECTS (Engine Coolant Temperature Sensor). This can fool the ECU into thinking that the engine is warm when it isn't, and not provide a rich enough mixture to allow starting at cold temperatures. The ECU has no way of knowing that the ECTS is misleading it, and doesn't turn on the CEL in this case.
You mentioned that the engine was "just overhauled". Did you have the problem before the work was done? Does the engine seem to be cranking at the speed it usually does when it's this cold?
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OB99W, so glad to see your post here. I've read a lot of your other posts and you are subaru electrical system god!
I would really value your advice on this problem.Thanks for the vote of confidence, but I'm no god. This forum has plenty of knowledgeable contributors, of which I'm (hopefully
) sometimes one.Based on "I like to have things to be working correctly and I really like cruise, so I'm going to have to fix it.", I'd suggest you replace whatever is known to be bad (assumedly, the ignition switch). As has already been mentioned, getting the trouble code couldn't hurt. That can usually be done at no charge at major automotive supply stores like AutoZone, Advance, etc. Let us know the what you determine (the Pxxxx code, not the code definition).
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Hey all, I recently finished putting a 2003 wrx engine in a 98 RS using the wiring harness from a 2004 wrx, the only snag I am running into is the front O2 sensor. I am getting a P0031 code, I changed the sensor and it didn't fix the problem. I measured the voltage at the connector and got the following:
Small white wire-4.7v
Small black wire- 4.7v
Large white wire- 3.4v
yellow/red wire- 12v
The yellow/red wire is the 12v supply to the A/F sensor heater. The "large" (heavier gauge) white one is the ECU control line for the heater. If it's working/connected correctly (pulling towards ground), you should measure under 1.0 volt there. Since it's quite a bit higher, that's what's likely causing the P0031 code to be triggered.
I remember reading somewhere that there are two wires for the O2 sensor pinned out in the ECU differently between the years 2003 and 2004. Because I am running the 2003 ecu with the 2004 harness, this could be my problem, but I can't find it again to know which wires to change.Unless someone else knows the answer offhand, this might take a bit of detective work. I have the wiring diagram for the 2004, but not the 2003. The difficulty is that we don't know if there's a wiring difference, or just poor connections leading to a voltage drop. Even if the wiring is correct, high contact resistance could be either in the wiring from the A/F sensor to the ECU, or from the ECU to ground.
If you're willing to check a few things, we might be able to figure this out even without the 2003 info.
A2 and A3 are pins #2 & #3 of ECU connector B134 (diagram attached). Please verify that heavy gauge white wires are connected there. If so, measure the voltage at those pins relative to a good chassis ground and let us know what you get. You could also wiggle the connections at the sensor and ECU, and see if the voltage at those pins changes (which might require a helper, or long meter leads
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[...] see if you can find a "Vacation" pic for your year. [...]
Like this vacation grouping?:
http://www.ludicrous-speed.com/automotive/impreza/fsm/Impreza_2005/
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Some 4EAT Phase 2 info:
http://endwrench.com/pdf/feb2004pdf/4EATPhase2.pdf
That and other 4EAT (Phase 1 and 2) articles can be found at:
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[...]Also if the ECT sensor was bad, wouldn't that trigger the "Check Engine" light??
No, that won't trigger a CEL -- the ECU doesn't know it's being "lied to".
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Thanks again. I do have a factory manual but I did not find where they tell/show you physically where the relay is. The only thing I found (so far) is the wiring harness layout drawing which suggests it is near the "Main Relay" which I know I can access without removing or disassembling anything. Should I find the fuel pump relay in the same vicinity?I also have a dumb(er) question: What is the "TCU"?
Thanks again.
I'm the one who's feeling dumb right now. I just reread your first post of this thread, and realized that you have a manual trans. The TCU (Transmission Control Unit) is the computer for an automatic. Sorry, that changes things.
The fuel pump relay should be on the same bracket as the main relay, right above it. If we're both looking at the same service manual, try section 2-7, page 32 or so.
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P0122 indicates a TPS circuit problem. One possibility is a bad connection at the 20-pin main engine connector, B21 -- the TPS connects to the ECU via three of its pins. You could check that connector for corrosion, etc. It's one of those near the rear of the engine, passenger side.
I just read your previous thread. Another thing to check is that the replacement of the pigtail for the TPS was done well.
A voltmeter probing at the ECU and someone to wiggle the connections while the meter is read could probably pin down the cause.
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Thanks OB99. I will look at the wiring.
You're welcome.
Can someone clue me in as to where the fuel pump relay is located?You have to pull the lower dash panel, drop the TCU, remove the lower pillar trim, drop the fuse box and remove the bracket.
If you don't already have the service manual, get this:
http://www.main.experiencetherave.com/subaru_manual_scans/1997_Legacy_FSM/
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[...]Next I have to figure out if it is the pump itself or something in the pump electrical circuit. I think we can rule out the fuse so I guess that leaves wiring and, assuming there is one, the fuel pump relay. Correct?
Yes, there is a fuel pump relay, controlled by the ECU, switching the power to the fuel pump. The ECU and connections directly at it are rarely a problem. Corroded connections elsewhere (especially at the rear) probably occur at least as often as failed pumps. In particular, the ground connection for the pump is a suspect.
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Ok, I'll do all that tomorrow, and sorry if I seemed huffy, a little frazzled by this Subi I suppose, working on it is a claustrophobic nightmare to me, I like working on trucks, tractors. I have a fleet of old (60's) Dodges, simple and plenty of room around everything.
I like the engine compartment of my '69 Firebird.
I'd found the two wires going to the dimmer under the column a couple days ago, a Clear (odd) coated one, and Green if I remember correctly. Going across these two with the Ohmmeter would get you 0 resistance in one direction, and something like 1.825 (k?) at the other extreme.I tested the other dimmer (from the Legacy), basically the same results, except the high reading was a bit lower, like 1.325.
I suppose I could test it on Laura's car, see I get the same type of readings, and possibly eliminate the turn signal mounted dimmer for good.
Let's clarify the connections. The dimmer on the stalk is a 3-terminal device (potentiometer). I've attached a diagram of the connector that mates with the 83023FA000 Illumination Control Unit/Module. (It's shown from the perspective of the front of the connector, so if you're back-probing with the connector plugged in, the numbering will be "flipped".) The pinout is as follows:
1 - Terminal V3 of the stalk-mounted dimmer (an end terminal)
2 - Lamp control "output" (to all dimmable lamps)
3 - Terminal V1 of the stalk-mounted dimmer (other end terminal)
4 - Terminal V2 of the stalk-mounted dimmer ("wiper" terminal)
5 - 12 volt power in
6 - Ground
The above should allow verification of the stalk-mounted dimmer operation. As I mentioned before, make sure there's no short to ground on any of those three leads.
If the above doesn't agree with your previous measurements, etc., please let us know.
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You're welcome. Please let us know if it works out, when you get a chance.
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Actually, I only took out two bulbs, the center heater illumination bulb, and the shifter, which in fact had a blown filament.
That explains why you saw 12 volts on both sides of the lamp circuit, as I mentioned above.
[...] The other three wires are Blue/Blue/Brown, none of which are doing anything regardless of what I'm doing with the dimmer on the turn signal arm.[...]Although the wire colors you've given don't exactly match the diagram I have, it appears that those three are the ones from the dimmer control on the stalk. You could unplug the module and verify with ohmmeter that the control is functional. There should be a fixed resistance between two of the wires as the control is turned. From either of those two to the remaining one the resistance should vary as the control is turned.
Assuming that not "doing anything" means you measured no voltage on any of those three wires, it appears that the module is bad. However, you should probably verify that none of the three wires has an accidental connection to ground.
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i don't know. it's new and i have only driven it ~500 miles but i have no indications of having traction control.
although i don't really know what it is or what indications there would be inside the car.
There's a warning light and switch on the dash for TCS you could check for. If they exist, let me know, and ignore the rest of this post. Otherwise...
my only glimmer of hope with this code is that it is a circuit problem. but i don't know where to begin.thanks.
Luckily, I know where to begin, so there should be more than a glimmer.
I suspect that the car doesn't have TCS. There's an ECU pin that's normally grounded through the engine harness when there's no TCS, and the '95 engine probably doesn't have it wired in its harness. The 16-pin bulkhead connector B22 mates to engine connector E3. Take a look at B22 position #16 (diagram attached), and verify there's a wire there. Then look at the what would mate with it on the E3 engine connector. On cars that don't have TCS, position #16 of E3 should have a wire going to ground. If that position is empty on your '95 engine, that's almost certainly why you're getting P1104.
If you still have the original engine, take a look at its connector E3, #16, to verify.
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John, P1104 is a TCS (Traction Control System) code. So, before we go further, does your '98 OB have TCS?
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[...]Suggestions?
Try to determine whether there's lack of spark or lack of fuel. Once you know that, we can make further suggestions.
oxygen sensor problem
in 1990 to Present Legacy, Impreza, Outback, Forester, Baja, WRX&WrxSTI, SVX
Posted
Since the white heater wires read full battery voltage, it indicates that the ECU isn't pulling them towards ground at all. There are three possible causes:
1) The white wires could be going to the wrong ECU pins. I've now looked at many ECU pinout charts and wiring diagrams for the '03 and '04 WRX, and they all seem to agree with each other and with what you've reported. However, the ECU info from Subaru could be wrong -- I've found lots of errors in FSMs over the years, some minor, some not so minor.
2) The ECU A/F sensor heater control circuit could be defective. It's rare, but not impossible.
3) The ground wires used for the heater could be on the wrong ECU pins -- see 1).
I'll admit to not being familiar with exactly what is necessary to perform the transplant that was done.
Lushy, did this involve a lot of snipping/splicing, as EastCoastEJ22T has mentioned?