2004 Subaru Outback FUBAR

97K miles on an automatic that has run well until recently. For about 4 months there have been brief episodes of hesitation & erratic shifting. 2 wks ago, the AT oil temp light flashed for a few minutes; husband changed trans fluid & filter per some info he found online about the AT oil light flashing.



On Monday, the hesitation & erratic shifting increased, AT oil temp light flashed continuously & check engine light came on. At a Subaru dealer (out of town), they found a code for throttle position sensor and advised me to drive it and see what happens. My husband found code P1700 and 45 that night.



On Tuesday, the car died dead while 80 mph on e-way. Tach went to 0, back up and back to 0; fuel gauge went to E. Temp gauge was all over the place. Car would not start and all dash lights remained on when the key was removed from the ignition. Futzing with the shifter caused the lights to turn off. Towed to the dealer where I live and by then, the battery was dead.



Dealer replaced the battery and the brand new NAPA trans oil filter w/ a Subaru because they said it messed up the pressures. Car started then but continued to run/shift erratically and stalled out when the mechanic drove it; it restarted after a time for them. Dealer can get no codes and says the scanner and computer are not communicating. They want to replace the ECM but admitted they have never seen this problem and only replaced one ECM in a car that was struck by lightening. The mechanic was not certain there was not a problem external to the ECM that caused the car to stop or fried the ECM, if it is indeed fried. They say they verified that the car is getting spark and checked all the grounds.





We went to retrieve the car today with plans to drive it to another mechanic for another opinion and it would not start. The car started with a jump but died within a minute and would not restart. We pulled it home where the battery was found to have 1.7 volts. It’s on a charger now. Once on the charger, the radiator fan came on and my husband had to remove a fuse to get it to go off.



There was mild & brief hesitation at about 37 mph when I first got the car new; took it back to the dealer twice then and they found nothing. Finally I forgot about it and the car’s been fine. My husband (a retired mechanic) has done regular maintenance on the car. I drive the car everyday and feel like there was an intermittent transmission problem: hesitation, erratic shifting, sometimes abrupt shifting. Now, it’s a way bigger problem than that.



Anyone have suggestions??

It sounds like you have a sever wiring problem on your car. As if the wiring harness had multiple crossed wires. Sometimes, a bad battery ground will cause the kinds of problems you describe, and you need to check the current capacity of the battery rather than the voltage. Alternatively you can check the specific gravity of the battery, both are better checks of the condition of the battery than a voltage check, at least in my humble opinion.
however, I have to wonder about the service intervals being kept, since you say our hubby changed the fluid and filter after the initial problems with the tranny, rather than having said the tranny was serviced regularly at the recommended intervals.

Regarding the transmission issue, I am thinking along the same lines as ignoramus9, namely that if the recent trans fluid and filter change at 97k was the first time that the trans was serviced, then this has some bearing on the shifting problems.

Regarding the apparent electrical problems, I think it is possible–bordering on likely–that your alternator is failing. When an alternator begins its death throes, it will usually put out inconsistent voltage, and this is something that causes a myriad of problems with electronic devices. Virtually everything in your car is an electronic device, or is activated/monitored by an electronic device. Throw wildly varying voltage at these devices, and they will rebel in some occasionally bizarre ways, including fluctuating tachometer and other dashboard gauges.

Another clue to a dying alternator is the dead battery a few days ago and the weakness of the new battery. If the dealership did not test the alternator output, then they missed a very important diagnostic step.

The hesitation and what feels like erratic shifting could be engine driveability problems, rather than transmission problems, and could stem from the aforementioned dying alternator. I suggest that you address the alternator issue promptly before you kill another battery and wind up getting hauled to the dealership again.

Incidentally, I REALLY hope that the car was placed on a flatbed auto transporter, rather than towed recently. If it was towed, then your transmission probably is toast by now. A car with full-time AWD of this nature CANNOT be towed without severe damage taking place.

I agree with everything cdcd says here.

Who is “cdcd”??

FWIW, the car was NOT towed, sorry for my inexact choice of words. The battery is sealed. Manual says only maintenance on trans fluid is to inspect it unless the car is driven under extreme conditions (mine is not); the filter is a life long filter and not replaced unless it is leaking or damaged. Routine maintenance has been done – filters, plugs, oil changes, etc. In Feb 09, the cylinder head gasket, timing belt, water pump and related gaskets were changed. In August 10, the R-side 1/2 shaft was replaced.

Checking all the grounds himself, my husband found a loose set of wires/ground; I could turn the bolt with my fingers. Tightened the bolt, test drove and all was well in Subaru-land. As a test, we loosened the bolt and recreated the problems described above. Tightened the bolt and problems resolved. I just drove the car for 40 minutes with no problems whatsoever.

Obviously, the dealer mechanics did not check the grounds as they said they did. That is very discouraging.

Of course, I don’t know if the intermittent drivability problem that I “read” as a transmission problem will return because they were intermittent. I’ll be going on a 100 mile drive tomorrow and time will tell. It seems the car did not need a $543.00 ECM or $35 trans oil filter, labor additional. Probably killed the battery when the car failed on the highway.

Thanks to those who responded. I hope this is the end of the story!

The only vehicles that meet light duty service requirements are those that seldom ever leave the garage.
Your car meets the severe service requirement with the next step being “more severe service”.

The trans fluid should be serviced every 30k miles on an automatic no matter what the manual says. Owners manuals, and not just Subarus, make many recommendations that are fine from a PR standpoint but not so fine for the well-being of your car.

OK–You are correct, of course, and I was tempted to post something similar.
However, I didn’t post it because I assumed that the OP would not return to this thread after the driveability problem was rectified.

Hopefully she will return to see what we know to be true, namely that automatic transmissions do need to be serviced every 30k, no matter what the mfr’s maintenance schedule may say.

sorry, thats a typo, it was meant to read VDCd.