TCU Code 24 w/ NO torque bind

[wallaceg]

Car info: 1997 Impreza wagon, 2.2L, 4EAT, 160000 mi

 

Last Friday the "AT Temp" light flashed quickly after starting the engine. After looking around on this form I figured out how to read the TCU error code. Turns out it's TCU code number 24, the dreaded "Duty Solenoid C."

 

The vehicle exhibits no signs of torque bind and idles itself around in circles in both directions just fine. AWD seems to be functioning fine (no wheel slip on loose gravel). The transmission fluid is at the correct level, looks pink, and smells fine.

 

The problem first appeared at the same time as a dragging right front brake pad. Not sure if the trans problem might be caused by the brake issue. I fixed the brake problem but the blinking AT Temp light remains.

 

Any suggestions on the next move? Also, where can I find fuse 14? Sounds like I need to remove it to clear the code.

 

Thanks!

[Legacy777]

The fuse should be in the driver's side kick panel area.

[wallaceg]

The transmission has been behaving normally for a while, then the AT Temp light flashed again yesterday afternoon. No flashing this morning. Error code 24 again. Is this a sign that the Duty C solenoid is failing? Any easy fixes that might help? (i.e. changing the trans fluid) I don't have a garage to work in so dropping the trans is out of the question.

[Legacy777]

Changing the transmission fluid would probably be my first recommendation if it has not been changed in a while.

[johnceggleston]

my son's 95 had an intermittent AT Temp lite and since he never wanted to hang around long enough to fix it we pulled the rear section of the drive shaft and he's still driving it like that 2 years later. knock on wood.

 

before we pulled the shaft we put the FWD fuse in and that elimnated the problem SOME of the time, not always. that's why we pulled the drive shaft. i suspect heat may have played a part in the problem but i have nothing to really base that on. i did try a different TCU but that didn't help in our situation, so he's driving a FWD subaru until .......

 

 

having a tcu code 24 without torque bind seems very very odd to me if not impossible, but never say never.

 

please don't take offense, but...

are you sure you checked the tcu codes and not the abs codes?

are you sure it is code 24?

does the trans operate correctly in every way, shifting, torque converter lock up, downshifting, ect?

 

this seems so odd to me that my first inclination is that some how you have some bad information. if you are sure of all of the above info my guess would be a bad connection or a bad TCU. it seems odd that either could throw a code and not cause torque bind but who knows? i might swap in a different TCU if you can get one extra cheap, or free, or borrow one from a friend and return it after you learn if it helps.

 

since the AT Temp lite blinks at start up in the NEXT drive cycle, when you test the car for torque bind and find it is clean, turn it off and then re-start it, looking for the blinking lite. there is a possibility that your problem / duty c is intermittent and you just didn't notice the torque bind on the previous drive.

 

i hope this helps. i'm afraid it is a little disorganized.

 

let us know what you learn.

Edited April 23, 2010 by johnceggleston

[wallaceg]

No offense taken, John.

 

1) Yes, I checked the TCU codes and not the ABS codes. This is a 97 Impreza L and does not have ABS. I checked the codes by plugging the diagnostic lead into the connector under the dash, shifting through the gears in a specific order, then depressing the accelerator. The AT temp light then started flashing the code.

2) Two long flashes and four short flashes = code 24, correct?

3) There is some vibration on occasion when stopped in gear. It goes away if you shift to N then back to D, or if you roll forward a foot or so. Giving a little gas when stopped in D does not make the vibration go away (i.e. not caused by a low/stumbling idle).

 

I did not noticed any torque bind in regular driving on the trips immediately before it flashed. After the light flashed I did the driving-in-circles test in a parking lot and there was no binding.

 

What exactly is the fault condition for code 24? Open circuit? Short circuit? Can I ohm-out the solenoid externally? I'll try to find the connections for the TCU wiring harness and see what condition the cables are in.

 

Thanks!

[wallaceg]

Well, the car has started binding on sharp turns. The problem is intermittent. Most days it drives fine, but about one day a week it binds on sharp turns at low speed. The FWD fuse sometimes works but sometimes doesn't (i.e. FWD light sometimes does not come on). Transmission fluid was changed 6 months/10k miles ago. Still reading TCU code 24 about once each week.

 

Anything else I should try before I take it to the shop and have them replace the Duty C? Any recommendations on shops in the Boston area to do the work?