N.B. The major problem here is that the fault reported is intermittent.
Solenoid C is a normally closed solenoid and when energised control pressure is bled off, such that the centre clutch is not closed.
The fuse is not directly connected to solenoid C and completes a circuit only to the ECU, which in turn energises the control circuit to the solenoid and illuminates the dash pilot light. The fault could possibly therefore be be within the tcu.
However alternatively, it could be that the TCU is as suggested programmed so that the signal is not held permanently. The fact that the pilot light goes out is of interest. Note the post included here:-
Merz-----My transmission does the same thing. The FWD light shuts off occasionally while i am driving and i start to get the binding. I just push it into neutral and turn the key off and on and it usually goes back into FWD.
However I have not noticed any other member using the fuse to operate in FWD mentioning this as occurring. But, where they doing so on a permanent basis?
As previously pointed out, according to the manuals the diagnostic system is quite sophisticated and will register an obstructed, sticking, or mechanically faulty solenoid valve. This can be achieved by sensing the inductance of the solenoid.
The first a procedure required is to check for a stored code. This will not give a definite answer to the problem, but could provide a clue as to the real issue, which is the cause of the centre clutch not disengaging when under normal control. Granted that the two issues could be caused by the same fault.
Of relevance to date:-
LAN states that this problem has nothing to do with the trans I bought from him, therefore there is no issue of warranty involved. After talking with him several times I am getting the impression that he is trying to be honest and isn't just avoiding the issue.
Tom suggests ------ My guess is a pinched wire in the transmission. Best way to check is, disconnect the transmission plug (the bundle going into the driver's side of trans) and test the sol. C signal wire to s see if has voltage. Remember, you need to test all of this while the car is on and the FWD fuse is not working (meaning it is installed but the light on the dash is out).
This plug provides electrical access to the solenoid. Disconnected from the loom, the resistance between terminals 11 & 4 should be 15 ohms, being the solenoid coil. Terminal 4 should register zero ohms to ground and terminal 11 register 15 ohms to ground.
A plug diagram, i.e. B14 to T2, has been kindly provided within a previous post. N.B. The socket connected to the TCU is illustrated so that you will have to transpose the positions to determine the plug connections.
Applying a pulse of +12 volts between the connection registering 15 ohms and ground, should result in the solenoid moving and a clicking sound being audible at the rear of the transmission. It should be easy to do this this test using a light wire from the battery positive.
Taking into account the comment,
“I don't have the money, time or ambition to throw parts at this issue. Well basically the last thing I want to do EVER is just throw parts at a problem, so info would be appreciated.” I would strongly suggest checking for codes, as well as testing as suggested and report back. Once these results are available we should be close to a conclusion.
