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Indeed, the information we have needs clarification and some additional observations/answers.

I would think that much, if not all, of what we have offered would have been considered, and tested out, by the mechanic and the Subaru technician, certainly before going as far as changing the ECU. But again, only a few suggestions, such as the TPS, have been mentioned by HeartMan, so we don't know what else, if anything, was already considered.

In this regard, IF they suspected the brake booster, it would have been a very simple task to disconnect and block the vacuum line off the manifold and then see what happens, in which case, HeartMan could confirm this so we can set it aside.

Also, as was mentioned earlier, by using a scanner that can monitor and log the engine parameters, there would be information on manifold conditions, fuel trim, injector performance etc. The Subaru Select Monitor can do this, as can RomRaider Logger -- but the technician has to go through the motions, and then analyze the data (know what to look for). Was this done? We don't know -- but if it was, what was found?

I guess we'll have to wait until HeartMan gets back to us.
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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It sounds exactly like my '03 H6 when the TPS was shot.

It could be a bad wire to the computer from the TPS, or something extremely weird like the throttle shaft not engaging the TPS for some bizarro reason. Ohm-ming the TPS pins while working the throttle would rule that out.

In the dark recesses of my memory I think I recall a really worn throttle shaft causing TPS problems.
 

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Discussion Starter #23
Symptoms have changed

OK, I am back again with more problems, but different ones this time. Following up on the suggestions about issues with the torque converter, I took my sad Subbie to the transmission shop. Initial inspection revealed burned trans fluid. A complete tear down revealed some burned disks in several of the clutch packs. So I had the whole trans rebuilt with all new soft parts and a rebuilt torque converter. Now the beast no longer stalls. But now the car is displaying a new symptom.

If I pull away from a stop very slowly and easily, everything is fine. The trans shifts very smoothly, you can hardly even sense when it shifts. But now when I try a faster getaway from a stop, at time times I get a nasty clunking sound, the speedometer drops to zero and the AT Trans Temp light flashes. If I back of on the throttle, things will usually settle down. The transmission shop spent three weeks on and off trying to chase down any problems with the wiring, connectors and grounds. On their dime, I might mention and then took $200.00 of of the bill for having my car tied up so long. But they were unable to locate the problem.

Today I took the car to one of the Subaru dealers in town. They worked on it most of the day and came to the conclusion that they think it is still a ground problem some where in the system. The problem is that the car will not display the problem unless it is being driven. When it is being driven it starts throwing OBD codes like flakes in a snow storm. They guessed that it might take two or three days (or maybe more) of technician time to locate the problem. Well at this point, particularly after paying for the trans rebuild, I can't afford many days at $90.00 an hour. So I have taken the car home. They charged me $45.00 for the diagnosis and a fancy car wash.

So now, does anyone have any suggestions where this poor sad sack might start looking for wiring and/or ground problems? The dealer told me that almost all the sensors in this car activate by providing a ground so that it could be some signal(s) getting ground at the wrong time (frayed wiring) or not getting ground at the right time.

Thanks for any thoughts.
 

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01 VDC, 05 R Sedan, 06 BAJA EJ257
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This sounds like a single issue effecting multiple systems. Has anyone checked the amperage output of the battery? Checked your alternator? Ground connections?

The ECM, TCM, ABS and Traction all rely on amperage supply to run their programming along with supply electrical flow to all their respective actuators and sensors.

Start with the battery.
 

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Discussion Starter #25
Good Thoughts

I appreciate your thoughts. I "think" I may have found another interesting finding. It seems that things are fine until the tach hits 2500 rpm. Then things start to go crazy. This behavior might be tied to your alternator idea. I think the next thing will be to hook up a current clamp and an accurate volt meter. Then follow the current and voltage when things seems to be OK and when things go to pieces. I'll try this tomorrow and report back.

THANKS!
 

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Discussion Starter #27
Might be?

This rev sensor seems to be tied up with the air conditioning compressor. I found your post from last January describing a problem with the rev sensor. I'll keep it in mind thanks.
 

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03 H6 OBW & 06 WRX Sportwagon
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This rev sensor seems to be tied up with the air conditioning compressor. I found your post from last January describing a problem with the rev sensor. I'll keep it in mind thanks.
ugh, sorry,

I will say, the wife's 03 OBW set weird codes on 2 different occasions when the battery had a bad cell.
 

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06 OBW 2.5, 05 Forester, had 03 H6 OBW
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It's known that low voltage or a bad ground will cause all sorts of mayhem, so that's an excellent place to start.

Voltmeters are cheap, and grounds are often overlooked when major repair work is done.

Might be able to use the voltmeter to find a bad ground, attach a wire to (-) on the batt, and wires to the trans, motor, body, run the wires into the car, drive around, have someone check the voltage between the (-) and those other test wires.

I had minor corrosion of the grounds that go to the right side of the engine, looked OK but saw some crud when I pulled it apart, cleaned it all up and it got rid of a minor hesitation.
 

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Discussion Starter #31
I am currently "Instrumenting" the car to to follow presumed ground voltages as well as current and voltage on the battery and the alternator. Fortunately I have access to a clamp on current probe.
 

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Discussion Starter #32
OK, since my last post, I found burned transmission fluid. The trans was torn down to find several burned clutch packs and a couple of sticky solenoids. The trans was rebuilt and the torque convertor was replaced. Now the car has a new issue. The car will at times smoothly accelerate, go through the gears smoothly and no longer stalls. But often at seemingly random times, there will be a very disturbing clunk in the drive line somewhere, the speedometer will go to zero, the tach will climb to an unreasonable value and the trans temp light on the dash flashes. The car spent an additional two weeks in the shop where the trans was rebuilt. They could not solve the problem. Now the car is at a Subaru Dealer where the car was originally purchased. It has been in this shop for two weeks. The Subaru Shop Manual for troubleshooting issues, comes to the conclusion that it is either the Transmission Control Module or a wiring problem. They have traced every wire that the manual specifies. There are no open wires and no shorted wires. Today, the installation of a brand new TCM made no difference at all. I find it unconceivable that this car cannot be repaired, but I am at wits end trying to figure out where to go from here. At this point the car has been in three different shops and has been literally un-drivable for over 10 weeks. The Subaru dealer has even consulted with the zone rep about this issue. I purchased the car with 98,000 miles on it. It had every possible bit of maintenance during those miles. Now it has 114,000 miles and at this point wouldn't even make a reasonable boat anchor. ????????????????
 

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I like your wheel speed sensor hypothesis early one. Do you know if any of the wheels had their bearing replaced without an OEM part? I'm sure there is some round about feedback from that speed sensor.

Tom
 

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But often at seemingly random times, there will be a very disturbing clunk in the drive line somewhere, the speedometer will go to zero, the tach will climb to an unreasonable value and the trans temp light on the dash flashes.
Just wondering . . . Vehicle speed sensor failing?

If the AT Temp Light on the dash flashes, there should be a transmission trouble code. That would help locate the area of the fault. Has anyone checked for codes? If there is a code, or codes, which one(s)?
 

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Discussion Starter #35
I will ask about the possibility of a wheel sensor issue. The transmission never reports any codes, at least not while the car is sitting still.

Thanks
 

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Voltage and Amperage are two different things.

Put in a new battery and make sure the cables are in good condition and tight. Then remove and clean with a wire brush all the ground anchors on the body, firewall, transmission case at the starter, intake manifold and block.

Poor amperage flow will not only cause your lights to dim at idle, but it effects the function of every electrical part and actuator on the vehicle including the ones that caused the transmission to burn up. If the actuators are not getting sufficient amperage, they don't work properly. When they don't work up to par, you get burned clutch packs.

The alternator will also be effected. Lack of ground conductivity will not permit proper alternator function.

Think of it this way; how well does your laptop or phone perform on low amperage? Its the same with you car. Electronic controls of fuel, ignition, transmission, braking, cruise control, traction control, transfer case, stereo, AC, fans, lights, seats, wipers, etc., etc.. It all draws current from the system and it all starts with the battery. The more electricity you require from the system on a bad battery the worse everything gets.

And if you don't get this resolved quickly, your new transmission will start to go downhill again.




.
 

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Discussion Starter #38
OK, just like the election, the final answer has FINALLY been found. After almost 3 months, the problem was an issue with the transmission cable harness. Even though there were no shorts to ground an no open connections, there were some shorts between some wires. Unfortunately, I did not get a chance to see the old harness. I'm a bit worried about rodent damage. But looking at the entire picture, the guess is that wiring issues brought about the original damage in the trans and in particular the torque converter. Once the trans and torque converter were rebuilt, the wiring troubles still were causing issues with the drive train. But now after the harness has been replaced, my Subbie is running like a dream. The company that rebuilt the trans wants me to put a out 500 miles on the rebuild and then they will drop the pan and check for issues that may have been caused during the final diagnosis. If so they will fix it. I declare this thread officially closed. Thanks for everybody who made suggestions about this seemingly intractable problem!
 

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Heh, I had to fix the wires for my front wiper- groundhog damage!

Dog was going nuts around the car, I opened the hood, suuuuurpriiiiise!
 
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