Car: USDM 93 SS Turbo Legacy 4EAT
I had the 16 flashes, did the handshake and code indicated Duty C solenoid issue. I have slight torque bind at slow turns, with FWD fuse in place torque bind still occurs.
I replaced the duty C solenoid and the flashes persist and the torque bind is still there. While everything was apart I replaced the clutch drum with a lower mileage drum and did some sanding of the clutch plate grooves.
While separating the tail housing I pulled the housing out too far and pulled the wiring out of the pin to the duty C harness plug. I soldered on new connector. I installed the new duty C solenoid and applied sealant to the housing and started to put everything back together. I realized that I soldered the wrong end of the duty C harness plug so I had two identical ends!!! To save time I cut both harness plugs and just soldered them together and bolted the tailhousing back on.
The next day the torque bind seemed to go away, but the flashes persisted. The next day the torque bind came back. I don't know if my solder job was bad (not likely, i solder RC helicopter wires all the time with success), I pinched the wiring when I put the tailhousing back on, or messed up something when I pulled the pin off.
Anyway I started doing some diagnostics and am kinda stumped at this point.
I checked the resistance of the duty c solenoid and it is 24 ohms which is way out of the 1 ohm max range given in the FSM. The flow chart says to replace the duty C solenoid ground.
Does anyone know how to replace this ground?
EDIT: Here is some more info.
Links to FSM diagnostic procedure
To check the Duty C solenoid's ground disconnect connector from the transmission, and measure the resistance oftransmission connector receptacle and transmission case. I put the probe on pin 4 and the trans case and got a reading of about 28 ohms. The max allowed is 1 ohm so the reading I got would indicate a bad duty C solenoid Ground.
If you look at the pin out diagram you can see that the duty C ground is spliced into the signal wire going to the duty C. This is the line that I had to cut and splice.
The FSM flowchart states that if the ground line is out of the 1 ohm spec to repair the ground line. Unfortunately I don't have the transmission section of the first gen FSM. So in my mind the only way that I could replace the original ground would be to drop the trans, take it apart, and replace the internal wiring. Not an easy task.
However, in theory shouldn't i just be able to run a new ground wire from pin 4 to the chassis? It wouldn't be in a loop like the original wiring but that should provide a good ground for the TCU and should in theory provide a low resistance value?
If one looks at the wiring going into the 4EAT pin 4 ground loops into the duty C signal wire, so shouldn't running a new ground by tapping into the wire coming out of pin 4 work?:
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My other idea is to go and measure the resistance of the donor legacy at the junkyard and see if pin 4 of the donor car gives a low resistance measurement. If I get a high number then I know that something else is the issue.
When I follow the FSM procedure to measure the resistance of the duty C solenoid itself (pin 4 and 11 of the connector) I get nothing, which would make sense if I am not getting a ground.
Or is the ground going to the duty C inside the trans not your typical ground and one of the 'powered' grounds you find in a Subaru? I am also going to cut open the wiring loom going and see if the ground has a broken connection.
So perhaps the duty C solenoid was fine all along and I just have a wiring issue. If anyone has any ideas please let me know. I'll post back any findings I get as well.
Edited by monkeyposeur, 22 August 2017 - 10:47 PM.