Ok i have searched and searched and nothing is quite hitting my problems dead on. What seemed to be the most accurate symptoms of my car called for a new shift solenoid assembly. That did not work. My problems are the CEL is on at all times, and the S3 gear is at a constant flashing. In the attempts to start my car when it has been sitting for more than 6 hours, the car will not start up right away. It usually takes 9-12 cranks to finally get the car going. Then when i am driving it appears the car will not go into 4th gear. I am LOST NOW and also getting tired of my threads getting locked, when i am sitting here just trying to get help, because this topic has been talked about so much and being told to do a search. I have searched these forums far more than i would’ve liked. I no longer know where to start. Oh i had a friend do a ecu code read and the CEL blinked 6x. Does that help?? I know i can keep replacing parts from what i have gathered doing the searches but that is getting costly. Next up will be Vacuum modulator and then Lock-up solenoid and then after that i only have the MFR left other than getting a new tranny. Any specific advice to look at first??? Or does anyone have a exact gameplan i can proceed with?? I must mention this when i was replacing the shift solenoid i had to take off many things one being the battery tray. When i removed that i noticed on top of the tranny near the vacuum modulator (just under) there seemed to be a nozzle that looked like it should have had a hose attached to it maybe??? Could that be my problem?? HELP PLEASE!!!
I had the same problem. Your problem is the ENGINE COOLANT TEMP SENSOR. Code 6 on your ECU is telling you it’s the ECT. Also look on your TCM(Transmission Control Module), it’s located above the dead pedal on the driver’s side. If it’s blinking 10X, I’m almost 100% sure its the ECT sensor - that’s why your car is flashing S3. While it flashes it won’t let the transmission go into the last gear.
^^^^^^^^^^^^^^YES!!! i checked and it is blinking 10x… so i need a Coolant temp. Sensor?? Awesome… Thanks man. I just checked to see if acuraautomotiveparts.net had this item and they do not. Where do i get this sensor?? Also i just called my local dealer and there no such thing as the engine coolant temperature sensor, But they did say that it is probably equal to the TW sensor (Water Temperature sensor). Does that sound about right??
Yea it should be the same as a “water” temp sensor. I’m suprised that the local dealer doesn’t know it as the ECT. Anyways the ECT sensor is located next to the coolant “sending unit” where the upper radiator hose goes into the engine. They have one at Autozone’s website under “coolant temperature sensor” for $30.
^^^^^ Yea i just called NAPA and they know it by ECT for $27… thanks man… hope this works but every thing you said so far is right on the money!!
Remember you might have to reset the ECU after swapping it out. That shitty sensor caused me so many freakin headaches. I would have never guessed the coolant temp sensor would also scew with the transmission. Anyways good luck and tell me how it goes.
What your seeing on top of the tranny is the vent.It’s curved at 90 degrees.
Hey integra93gs, just wondering what symptoms you had when your problems arose that are similiar to mine??? i have not yet been able to replace that part yet it has been snowing here everyday and it is cold as hell out, been waiting for a half decent day to replace it.(No garage)
Just curious as to whether or not that little sensor is the cause of all my problems?? Also usually i disconnect the battery before i replace any electric part or sensor is that acceptable or rather replace the part and then start the car and then do the ECU???
I had pretty much the same as you. Car would start on 2nd or 3rd try -sometimes more, same ECU code and same TCM code(flashing S3). In my case the ECT sensor was actually telling the ECU that my coolant temp was -144 degrees, yea thats NEGATIVE 144. I guess a car will do weird things if it thinks the engine is frozen solid :sick: After I swapped it out which was over a year ago, I’v had ZERO starting issues and S3 flashing. 
Wha Wha… PROBLEM FIXED (ECT Sensor was LOOSE)!!! Thanks 1993integrags… If only i would’ve been a little more patient and waited for you to post, i could’ve saved myself $270 or so, oh well… happy that is behind me. IF anyone needs Brand New Shift Solenoids, let me know i have them.
Location of the Lock-up Solenoid - 1990 LS AT
:argh: 1990 LS Auto Tranny
I need to replace my Transmission Lock-up Solenoid but I am having trouble locating it.
Does anyone have any pictures of where it sits?
Do I get to it from the Top on the Battery side?
I have pictures of the parts, but I just can’t locate the little !@#$.
thanks.