2004 Outback 2.5 Revs High on Startup, Won't Shift, Gear Ratio Incorrect Code

[Wilshire150]

I'm cross posting this topic here from the subaruoutback.org forum to try to help out my sister who's having an awful lot of problems with her 2004 Outback which seems to be the most problematic car I've ever heard of.

The car is a 2004 Outback 2.5L, automatic, 90,000 miles.

The car was purchased in 2012 with about 70,000 miles on it, and it appeared to be in great condition. It was a single owner car with no accidents. About a year after it was purchased, her husband, a Ford mechanic, discovered the rack and pinion and valve cover gaskets were leaking, which are fairly common problems. He replaced the rack, the valve cover gaskets, and also replaced the head gaskets preemptively using auto parts store gaskets, not OEM Subaru gaskets. In early 2016, the car started overheating if driven for more than 20 minutes. Her husband replaced the thermostat multiple times, water pump, radiator, and did multiple coolant flushes. Eventually he decided to replace the head gaskets again, this time using Subaru OEM gaskets. The car still overheated after the second set of head gaskets, so finally he determined that the heater core was clogged, and he dismantled the dashboard to replace the heater core. The heater core corrected the overheating issue. Immediately after the heater core repair, the hood blew up while driving at highway speed because it had not been latched properly, bending the hood, breaking the windshield, and denting the roof and fenders. Shortly after the car was repaired at the body shop, the air conditioning stopped working and had to be repaired. A few weeks after that, the current problem started. At this point, the engine has been disassembled twice, the dashboard disassembled, and the front body has had a significant amount of work done to it, which is an awful lot of work for a car model that is generally known to be reliable and still has a relatively low 90,000 miles on it.

The current problem is that the car revs very high upon startup and will not shift. The car will drive at a maximum of 25 mph while the rpms approach redline. You cannot make the car go any faster no matter how much you press on the accelerator, only the rpms will increase. The position of the automatic shifter has no effect on the problem. Eventually there will be a "kick," and the car will start to drive as normal. If you warm the car up for 20-30 minutes before driving it, it will drive as normal.

After several days of exhibiting this problem, the CEL came on, and the codes were:
P0731 Gear 1 Incorrect Ratio
P0732 Gear 2 Incorrect Ratio
P0733 Gear 3 Incorrect Ratio
P0734 Gear 4 Incorrect Ratio
P1512 Idle Air Control (IAC) Valve Signal 2 Circuit Low Input
P1514 Idle Air Control (IAC) Valve Signal 3 Circuit Low Input
P1516 Idle Air Control (IAC) Valve Signal 4 Circuit Low Input

The transmission fluid has been flushed, the internal and external transmission filters have been replaced, fluid levels are all correct, the Throttle Position Sensor has been replaced, and the Idle Air Control Solenoid was cleaned. The battery has been disconnected over night to try to reset any memory.

Her husband the Ford mechanic is tired of working on the car, so she's now taken the car to a different trusted independent shop, but not one which is a Subaru specialist...those are nonexistent in her area. The new mechanic says that the transmission is bad, and that third gear is "falling out," which is why the car will not shift out of second gear until it's warmed up. It seems very highly unlikely to me that the transmission would fail within a month of all the other major repairs, and I have urged her to try to eliminate every other possibility before spending thousands more on a rebuilt transmission. Are there any sensors, electrical connections, or vacuum issues that could cause this problem? They have a transmission out of a 1995 Legacy on hand her husband would like to use, but I don't think that transmission is compatible with a 2004 Outback.

Any help would be most appreciated.

Andrew

Edited August 31, 2016 by Wilshire150

[golucky66]

I have never heard of something like this so I decided to look up the service procedure for the P0731. 

 

 

Maybe that'll help a little bit? It is certainly a weird issue. 

[Wilshire150]

Thanks, golucky. I'll pass this along.

 

Is there a sensor that would be tied to temperature and the transmission shifting? The transmission operates normally and shifts smoothly after the car is fully warmed up.

 

Does the revving and shifting problem sound like the car is going into some kind of limp mode? I know some transmissions limit vehicle speed and won't shift when the TCU detects an error condition.

Edited September 2, 2016 by Wilshire150

[golucky66]

Well, if the ECM/TCM thinks there's a gearing issue then it might not let it shift in attempt to prevent further "damage". There is a sensor on the tranny for temp. I'm not sure if an 04 had a higher shift pattern until warm (and by higher I mean like, won't go into 4th until warmed up, or shifts 500 rpms higher. Not won't shift at all)

 

So if you let the car idle until fully warm, it would then shift properly through all the gears?

So it only does this weird "won't shift out of 1st" when cold?

[Fairtax4me]

Has the engine been removed twice? How was the transmission supported while the engine was being removed? A jack under the transmission pan will dent the pan and can damage transmission internals. It could block the pickup of the internal filter. It could have damaged one or more of the solenoids in the trans.

 

The IAC code and high idle are probably because of a vacuum leak. A poor seal around a gasket maybe.

 

Seems to me like a lot of these problems are self induced. The hood flying open and subsequent body damage is the fault of the mechanic or driver, not the vehicle. There's no need for a preemptive head gasket replacement at 70k miles. Head gaskets replaced with poor quality parts, some one put stop leak in the system and blocked up the heater core?

[Wilshire150]

Yes, it shifts fine once it's warmed up, either by leaving it parked and idling it or driving it.

 

The engine was not fully removed to replace the head gaskets, but my sister's husband is a Ford diesel truck engine mechanic and not a Subaru specialist, so that lack of familiarity hasn't really helped. He keeps telling her the car is a real lemon, and he's tired of working on it. I've told him several times he needed to check for vacuum leaks.