Why else would the ATF Temp light flash?

[Off Road SHO]

Is it just a general flashing because there is something wrong with the Duty C solenoid or could there be other causes?

 

Tom

[monkeyposeur]

On the first gens the tcu will flash a code if you follow a procedure to turn it on. http://www.surrealmirage.com/subaru/trans.html

 

I found the procedure without a scan tool for second gens here: http://www.ultimatesubaru.org/forum/showthread.php?t=33331

 

Quote from rruge on ultimatesubaru.org:

" On-Board Diagnostics for the 4EAT Auto Tranmission

 

There are two varieties of trouble codes from the Transmission Control Module (TCM); Existing and Previous. Here is how to read the code without the Select Monitor tool.

Existing:

1. Move gear selector to D
   
2. Turn the ignition switch to On
   
3. Move the selector to 3, 2, then 1st gear.
   
4. Depress the gas pedal
   

Or Previous:

1. Move the selector to 1st gear
   
2. Turn the ignition switch to On
   
3. Move the selector to 2, 3, then D gear.
   
4. Depress the gas pedal
   

Next, watch the AT Oil Temp light. Here is the output:

1. Light flashes 4 times per second, you have a faulty battery.
   
2. Light flashes 2 times per second, all is normal.
   
3. Light remains on, check the inhibitor switch, diagnosis switch, wiring, TCM, etc.
   
4. Trouble code (see the next section).
   

Reading the trouble code:

1. Long light pulses (~1.2 seconds) indicate "tens."
   
2. Short light pulses (~0.2 seconds) indicate "ones."
   
3. Count the long, then short pulses.
   
4. Interval between codes are ~1.8 seconds.
   
5. Codes will repeat.
   
6. There are about 13 codes ranging between 11 and 33.
   

Trouble Code

11) Duty solenoid A

12) Duty solenoid B

13) Shift solenoid 3

14) Shift solenoid 2

15) Shift solenoid 1

21) ATF temperature sensor

22) Mass air flow signal

23) Engine speed sensor

24) Duty solenoid C

25) Torque control signal

31) Throttle position sensor

32) Vehicle speed sensor 1

33) Vehicle speed sensor 2

 

All solenoid issues, "detect open or shorted drive circuit, as well as valve seizure". All sensor or signal issues, "detect open or shorted input signal circuit".

 

Aside: although Subaru says that the TCM will, "detect... valve seizure", in my case the Duty Solenoid C seizure that I incurred was NOT detected by the TCM.

 

Good luck and may the force be with you.

 

Peace, out.... http://www.ultimatesubaru.org/forum/images/smilies/smile.gif"

[johnegg]

the flashing AT Temp light is a ''fault'' indicator. it means there WAS an electrical or other fault with the auto trans the last time it was driven.

 

as mentioned you have to read the code to know what the fault was.

 

duty C is a common fault , but other solenoids could also cause a fault / TCU trouble code.

 

or there are engine issues that can cause a trans codes, like TPS or MAF.

[Off Road SHO]

Thanks John and MP. I printed out the procedure and will report back what I find out. Brokeindark came over yesterday and put a new front halfshaft in for me and then serviced the front brakes for me (what a guy). He drove it afterwards and while turning on my gravel driveway, the car would exhibit the tire jerking associated with a locked center diff, but not on the asphalt.

 

Tom

[Off Road SHO]

Well, I couldn't follow that sequence at all. Without doing step 2 first, I can't move the selector to D or 1st. If I reverse the first two steps, I can then do the next two steps but get no flashing of the ATF light, only a buzzing sound from under the hood (I think.) Any other ideas?

 

 

Edit: I just cleaned the MAF sensor, even though it looked great.

 

I'm going to put the fuse in the FWD socket and see what happens.

 

 

Tom

[johnegg]

i would search for the way to read ''TCU* codes''. probably over on the usmb.

 

i think the directions above have left out the part about grounding out the #5? pin? on the test / diagnostic connector under the dash right of the steering column. it is a black? 6 pin connector and the wiring harness has 2 single pin ground wires included with it.

 

not all of the pins are actually there , but all of the pins are diagnostic. one for the TCU, one for the ABS, one for the SRS, ...etc.

 

do a search at ultimatesubaru.org . there are several threads that give some info but not all. if it have it bookmarked i'll post the link.

[Off Road SHO]

Thanks John. What is USMB?

 

I put in the fuse and not only did I not get a FWD light on the dash, but it also made no difference in the tight circle wheel hopping. I also didn't see a FWD light go on when I turn the key to on. Maybe my bulb is burned out?

 

Tom

[johnegg]

link to the single post: http://www.ultimatesubaru.org/forum/showpost.php?p=1111474&postcount=2

 

originally posted by general disorder on ultimatesubaru.org

 

if the AT Temp light flashes 16 times on startup then you have stored TCU codes. There is a 6 pin black connector above the gas pedal and two grounding wires wrapped into the harness directly above that. Insert one grounding pin into the center pin on the black connector (blue with yellow trace typically), then follow this process:

 

1: Turn ignition on, apply brake, and place gear selector in 1. Turn ignition off.

2: Turn ignition on.

3: Move selector to 2.

4: Move selector to 3.

5: Move selector to D.

6: Depress accelerator pedal slightly.

 

7: Read morse codes flashes on the AT Temp light. 24 will indicate a bad duty-c. These are "stored" history codes from previous drive cycles.

 

8: Turn ignition off, then back on.

9: Move selector to 3.

10: Move selector to 2.

11: Move selector to 1.

12: Depress accelerator pedal slightly.

 

13: Read codes again. Codes given here are current faults active in the TCU on the current drive cycle.

 

GD

[johnegg]

I put in the fuse and not only did I not get a FWD light on the dash, but it also made no difference in the tight circle wheel hopping. I also didn't see a FWD light go on when I turn the key to on. Maybe my bulb is burned out?

 

typically this means you have a bad duty C solenoid in the rear extension housing on the trans. it runs about $100 from online dealers and it can be replaced with the trans in the car, in the drive way. but maybe not when the air temp is in the teens or lower.

 

depending on where you live (snow) and how long before you can replace the duty c, you may want to consider removing the rear section of the drive shaft to relieve the binding. of course this would also eliminate 4wd as well.

[johnegg]

edit: it could be caused by the TCU under the dash. rare but possible.

you have to look at the circuit board for burns or scorch marks.

[Off Road SHO]

John,

 

I removed the rear drive shaft on my 96 LOB a year ago and never looked back. This 95 Legacy Brighton I'd like to figure out what is wrong. It's a balmy 70 degrees outside right now, but it is expected to get way down to the mid 60's tonight. I have a lift in my shop so removing stuff isn't a problem, would just like to be sure it needs replacing before I do. Thanks.

 

Tom

[Off Road SHO]

John, Thanks for the updated test procedure. With it I got code 24. So it's either the Duty C Solenoid or the TCU.

 

I am getting all kids of weird things happening now; fans cycling on and off, relays clicking... I think I'll just follow through on my original course of action and grab the 120K mile 2.2 out of this car and refresh it and put it in my 96 OB.

 

Too many problems with this 95.

 

Thanks anyway for the help.

 

Tom

[johnegg]

all kids of weird things happening now; fans cycling on and off, relays clicking..

this, with a bunch of CEL trouble codes, MIGHT be caused by the GREEN diagnostic connectors being connected under the dash.

 

they should not be connected for normal operation. when they are connected, they TEST all sensors? and relays on the car and will generate a ton of CELs.

 

EDIT: swapping the engine into your 96, will not correct what ever created the need to pull the dive shaft.

 

the TCU failure can cause binding but it is very very rare.

 

if you got a DUTY C trouble code, then that is the cause of the problem. this is common.

[Off Road SHO]

Any online sources for that solenoid?

 

Tom

[johnegg]

sure. two listed below, but there are lots of others.

 

www.subarupartsforyou.com they will even show the part number. but i sometimes have trouble knowing where to look for the part i need.

 

once you have a part number www.subarugenuineparts.com will give you a price. shipping is plus 10% usually.

 

go to either of these sites and print the price out, and take it to your local dealer. the parts guy MAY match the price. it happens all the time. i usually just say, ''i'm going to buy this part online , but i will buy it here if you can match the price.'' you may get the online price with out the shipping. in my experience, the online price plus the 10% shipping is the same as the ''wholesale'' price at the local dealer.

 

i would buy ATF from the local parts store.

 

http://opposedforces.com/parts it a great place to part numbers.

 

you will need the ''valve assembly'', and 2 gasket for the same. you do not need a gasket for the rear extension housing on the trans, a good quality RTV type sealant will work just fine. you do have to drop the exhaust so you may need an exhaust gasket as well. i think disconnecting at the head may be easier than at the front cat but yours may vary.

 

you will also need to drop the drive shaft, mark it at the middle support bearing and at the rear diff. i hear it is ''balanced' as an assembly so you want to put back the same way.

 

make sure the case trans does not pinch the solenoid wire during reassembly.

 

the 95 solenoid with 2 gaskets may be under $100. i think later years it is more. but i have not priced one recently.

 

one of # 13 and two of #10 in the link below:

http://opposedforces.com/parts/legacy/us_b11/type_28/automatic_transmission/at_transfer_and_extension/illustration_2/

 

 

good luck.

[Off Road SHO]

Thanks John. SubaruGenuineparts.com has it for 85.56. I will take a copy to my dealer and see if he will deal.

 

I changed the fluid and cleaned out the connectors on the bell housing; less TB but still there. Unplugging that test connector under the dash and disconnecting the battery for two minutes cleared all the flashing check engine light and stopped all the relay clatter.

 

Dang this is a smooth running engine, but I've noticed that it idles a little low sometimes. Is there an Idle Air Bypass on these engines? I don't see one external to the throttle body.

 

Tom

[johnegg]

it is called the IAC, idle air control, and is located on the passenger side rear corner of the intake.

 

it sounds like you have some experience with engines, but not much with subarus. so i trust you know not to adjust the small screws on the throttle body. unlike carburetors of the past they do not control the idle. the computer does, based on the info it has.

 

i can't help very much other than to suggest you look for vacuum leaks.

[Off Road SHO]

Damn you're good; we found a dry rotted vacuum line. I couldn't hear it but my son could, found it with a propane sniffer. I fixed it but ran out of vacuum line; will get a new roll and replace them all.

 

Is there an Idle reset procedure? This model doesn't have a tach but it sounds and feels very low.

 

Tom

[Off Road SHO]

Well my dealership was just 8.00 more than online so for a total of 96.00 for solenoid and two gaskets, I will buy it from them.

 

Tom

[Off Road SHO]

I've been pouring over the electrical diagrams all morning and for the life of me I can't find out how to trouble shoot a Duty C Solenoid while it's still in the transmission. I found the pinout location; Connector B pin 6, a red with yellow stripe wire, but can't find what the resistance should be when measured.

 

I have a new one coming from the dealer but would like to know what a good one should read in the vehicle.

 

Tom

[johnegg]

post #8 shows the TCU pin out and the resistance / voltage i think?

not sure which year but it should say somewhere.

 

FYI: the TCU is under the dash above the brake pedal. silver color, 2 bolts, 2 wide connectors, 16 pin and 20 pin.

 

also a pretty good thread on binding and the TCU.

 

http://www.ultimatesubaru.org/forum/showthread.php?p=996223#post996223

[Off Road SHO]

John,

 

Thanks. I think those voltages referenced in post 8 are from the TCU, correct? I'm looking for what resistance I should see across that duty C solenoid.

 

I took out my TCU and opened it up looking for any signs of heat build up but found none. Bought another one from a local Subie guy and after I check the tranny's selector switch and it's relevant connectors, if the problem is still there, I will replace the TCU and see if that does it.

 

Tom

[johnegg]

the wire circuit for the duty c needs the 9 - 15 ohms resistance. i know this because when the guys install the ''4WD LOCKED'' switch which disconnects the duty c, 9 - 15 ohm resistor is what makes the TCU happy.

 

so find the pin on the wiring harness and measure the resistance to ground. or just compare the new one to the old one.

[MakoTako]

Hey Guys, recently had this happen to my 98 Legacy Wagon GT. I did everything, replaced all vacuum lines,hoses, cleaned IACV twice!, Cleaned throttle, MAF, did the 3x Drain refill of trans fluid, changed knock sensor. After all that, car was still stalling, AT Temp Light still Flashing 16 times. Finally figured out how to read the TCU thanks to all of you guys, got codes 22 and 23. I figured I would change the MAF first as hoping that this would help with the idling and stalling. Ordered a Dorman 917-801 Mass Air Flow Sensor from amazon and after the 5 mins install, all my troubles went away. No engine stutter, no hard shifting, no stalling, no nothing. Thanks for all the help and info guys and I hope that this helps someone else down the road.

 

Mako