Failed transmission

[frprof]

I was driving my 1990 Ls400 and suddenly the trany went out as neutral. I packed and after a while started and it came up.  Not long it went out again. I noticed that each moment I stopped,  turn off engine wait for a moment and turn on again it came up. I continued the the turning off and turning on,  to drive to a safe place as far as 120km until it packed up completely.  I scanned it and got transmission code 63/67 saying OD clutch sensor malfunction.  I was told I need to replace a complete transmission.  My Ls400 has put in over 500,000km

1. Please is there anything I could do to fix without replacement of complete transmission? 

2. Where is the location of the OD clutch sensor and how may I access it? 

Thanks in anticipation 

[paulo57509]

I'm not a transmission expert nor do I have experience in diagnosing your particular problem.  I'm posting the following in general terms as to what you can check and what may be happening.

1.  Have you checked the fluid level?

• What color is the fluid?
• Does it smell burnt?
• Has the fluid ever been changed?

2.  Who told you that the transmission needs to be replaced?

• Other than the trouble codes, has any other diagnostics been performed?

You have two separate trouble codes: (http://www.lexls.com/tutorials/intro/codereading.html)

• 63 - Open or short circuit in No. 2 solenoid valve
• 67 - OD direct clutch speed sensor signal malfunction

Code 67 is most likely just a symptom because the car won't move.  The engine control unit (ECU or "computer") is is getting an above idle throttle position signal, transmission in drive range signal and an elevated engine RPM signal; so it's expecting to see a speed signal from the speed sensor to tell it that the car is in motion.  Since the car doesn't move, the ECU "thinks" the sensor has malfunctioned.

Code 63 is most likely the cause.  However, the fault could be the solenoid itself or in the electrical circuit for the No. 2 solenoid.

I don't know exactly what Solenoid No. 2 does.  It is most likely a solenoid that controls up/down shifts.  However, the symptoms you describe sounds like a transmission fluid pressure issue - there is a solenoid or solenoids inside the transmission that controls fluid pressure.  It may also be the fluid pump.  Driving the vehicle with inadequate transmission fluid pressure may damage the unit.

For problems that you describe, it is probably best (cost effective) to find a transmission specialist that knows Aisin/Borg-Warner A341E transmissions.