danaroypatton

Is there a transistor somewhere? I don't understand that voltage.

At Josh's advice, I checked input voltage at the TCU. Here's what I found: TCU terminals B83/1 and B85/6 are both receiving correct voltage, between 11.5v and 13.8v, when the switch is ON. TCU terminal B84/14, however, is not. It is supposed to receive 10 to 14 volts when the switch is OFF. It is receiving over 33v with the switch ON. It drops immediately to 5v when the switch is turned OFF, then quickly descends through 4v, 3v, etc., down to 0v within one minute. So, B84/14 fails the Subaru specs when OFF. I also doubt that the 33v while ON should be occurring, either. The above voltages are present both when the transmission is shifting normally and when it enters failsafe mode. I read no change whatsoever in either scenario. Thanks, Dana

I bought the car without a transmission.

Thanks guys. I'll clean some connectors and check voltage at the TCU this week, then let you know what I find.

Hello. Thanks in advance for reading. A bit of a long post, I'm trying to provide as many details as possible. History I recently swapped a '95 4EAT (90k) and rear differential into my '92 Legacy L AWD Sedan. The original final drive ratio was 3.90, and is now 4.11. However, the winter tires I am using are significantly larger than the factory tires (I do not have tire clearance issues, BTW). The factory calls for 185/70 14s with a circumference of 76.017 inches, and I'm running 195/75 14s with a circumference of 80.161 inches. At the advice of the local Subaru guru, I did NOT swap the TCU. The steeper gears combined with the taller tires is a near-perfect match IF there were to be a TCU issue: 3.90/4.11 = 0.949 76.017/80.161 = 0.948 I've also verified this by calculating my speed through several mile markers. Symptoms 1) Intermittent, totally random failsafe mode (stuck in 3rd gear). This can happen at any speed, at any time, and for any duration. It can be downshifting normally as I slow to a stop, only to go into failsafe as I accelerate. I can drive it for 30 minutes on the highway with no problems when it suddenly drops to 3rd and revs. It can happen first thing in the morning when cold, or not. It can be in failsafe for two seconds or fifteen minutes. Totally random. Overall, it seems to fault approximately 25% of the time, and is not getting better or worse. 2) When it exits of failsafe mode, I receive one and only one power light indicator flash. I receive no indications when the 4EAT enters failsafe mode, and I am even sometimes unaware the the transmission has faulted until I observe the one flash. Occasionally, I also get one extremely fast AT temp indicator flash. This happens very quickly. So quickly, in fact, that I can barely even tell which indicator came on. The AT temp indicator may be flashing every time the power indicator flashes, but I don't think this is the case. I cannot tell because when I am able to visualize the indicator, it stays lit for just a split second. 3) Occasionally, but much more infrequently then the symptoms above, I receive the 16 power indicator flashes, indicating a stored TCU code. When I am able to retrieve the codes, I always receive a 32 and a 33 for vehicle speed sensors 1 and 2. 4) As to 3) above, I cannot always retrieve codes. When I follow Josh's code retrieval steps, the power indicator lamp does not always come on in step 3. Actions I've changed the fluid twice. It is always bright red with no burnt odor. I've used 1/2 bottle of red LubeGuard each time. I always keep the fluid right on the full mark. Next I do not think that I have a mechanical issue with the transmission. The intermittent but binary nature of the symptoms, combined with occasional lack of power indicator at startup point me to an electrical issue. I could try a '95 TCU, speed sensors, cleaning the transmission connectors, or cleaning and adjusting the throttle position sensor. Any other ideas? Thanks for the forum, the great write-ups, and the good community attitude. This is my first Subaru and I've had fun learning not only about my car, but what everyone else is doing. Dana