P0741 - Does this make sense?

[Alisoncc]

Recently had a DTC P0741 error code - relates to Torque Converter Clutch Circuit Performance or Stuck Off Lock-up clutch is faulty or valve is stuck.

Outback compliance date 04/04 4GEN MY04 Odo +-175,000kms sold with extended warranty, provided through a third party. Rht Hnd drive (Australia).

Took Subbie into workshop yesterday am. Call from them in pm to say Lock-up solenoid ordered was incorrect part, and would need to keep overnight. This morning call to collect vehicle. On arrival told by manager that they had been unable to do anything as my transmission was "Revision 2" and the solenoid was matched to the "case/valve", and they would need to replace the full cover with all sorts of other kit that was attached. Could run into multiple thousands of dollars, and there may be a warranty issue.

Sounds very suss to me. Would appreciate any comments. Thanks.

[cardoc]

For one, I don't see why the shop can't get the correct part. Did they even diagnose it properly? The Phase II transmissions were all the same through Gen 2. Gen 3 saw valve body changes to improve shifts and MPC engagements.

Here is a post by PlainOM from 4-12-2010 concerning the change in Phase II transmissions to an updated valve body.

"Plain OM 04-12-2010 06:50 AM
There was a change in the Phase II 4-speed automatic around 2004-5. Although outwardly it was not evident, inside the changes were relatively significant, at least in my view.

The major change was the elimination of accumulators in the control system -- the new version uses better duty solenoids and a more sophisticated TCM program to control the shift clutches directly. (Previously, a solenoid would open, passing fluid into an accumulator, which in turn would act on the shift clutch or brake band or whatever it was controlling. Now, the solenoid acts directly on the functional element.) In addition, the clutch piston seals were revised to further improve control.

Another significant change was in the AWD system. The AWD duty solenoid ("Duty C") and the transfer valve, which had been located in the extension case, were moved to the main valve body itself on the underside of the transmission. Along with this change was a change in the AWD "failsafe". In the earlier version, the default condition in the event of a malfunction in the AWD control system was a fully-engaged transfer clutch, leading to noticeable torque bind when turning. With the revision, the default is the opposite -- failure of the control system (e.g. open connection to the AWD solenoid) results in no power being transferred to the rear wheels.

These changes coincided with the shift to electronic throttle control, which enabled better coordination of the throttle, engine control and transmission control. This change occurred earlier in the turbos, and was introduced to the general Legacy/Outback platform with the 3rd generation in 2005.

The Owners Manual wording for the proper ATF has also changed over the period of the 3rd generation, ranging from HP is "recommended" for the 4EAT, to "required". But the reference to increased vibration and noise seems to be repeated. Subaru "TechTips" had a short article on this in late 2006 and again a few months later, in which it was more emphatic -- HP is required in all Subaru ATs from MY06 onwards. HP should be available at Subaru dealers. The other brands that are mentioned don't seem to be marketed in North America."

Also, in the American market, the part numbers changed between 2004 and 2005 models for the 4EAT. The American models are a year behind the European markets, so I assume your transmission could be either version. Still, a competent transmission tech would be able to tell the difference between the two valve bodies upon visual, if he works on Subarus regularly or pays attention. All else fails, the shop could decode the transmission number on the front case. There shouldn't be a need to modify anything. Just get the correct part.

I think you may be dealing with inexperience.

[plain OM]

One of the downsides to the later version is that the solenoids located on the valve body are not individually replaceable as they were earlier. This is reflected in the relevant factory service manuals and in the parts lists at http://opposedforces.com/parts/.

This doesn't mean that with some ingenuity suitable replacements couldn't be found and used, but they are not being supplied by Subaru. Faults in the valve body require replacement of the assembly. I suspect that's what the workshop manager is referring to.

Not clear on the warranty issue. If the car is covered by an extended warranty, does it cover the transmission? If it does, then I would think that a failed solenoid would qualify, and if that means changing the valve body assembly, it should be covered.

[Alisoncc]

Originally Posted by plain OM

One of the downsides to the later version is that the solenoids located on the valve body are not individually replaceable as they were earlier........Faults in the valve body require replacement of the assembly

Thanks for that. Now it does make sense.

Originally Posted by plain OM

Not clear on the warranty issue. If the car is covered by an extended warranty, does it cover the transmission? If it does, then I would think that a failed solenoid would qualify, and if that means changing the valve body assembly, it should be covered.

Third party providing extended warranty coverage, and transmission is covered. Initial quote provided to them by workshop for approval most likely just specified single replacement solenoid. Now significant increase in cost.

Indications of diagnostic error only occurs whilst driving on freeway, never locally around town, which would suggest it is the lock-up solenoid itself that is failing.

[NWSub]

i have found this usually mean that the obd sensed some slippage in the torque converter. could be a bad seal, solenoid.

My bmw has had this code for 75k miles and runs just fine. I have been waiting for it to die before i replace it as all the places just want to slap a rebuilt in reguardless. so may as well let it die before i do anything.