ok... my moms 97 civic ex 1.6L sohc is having some troubles. it had the transmission replaced (with used), worked fine for a couple weeks. she replaced the radiator fan switch (a coolant sensor on the back RH of the engine). Then ever since then the D4 light has been blinking (on the dash) and vehicle seems to shift hard. i am a trained mechanic, but not honda specific. i scanned the vehicle for codes and got several. i cleared the codes then drove it till the D4 light started blinking again. scanned codes again and all the old codes came back. ---- P1382-P0700-P1753-P0720-P0730---- one is for the output shaft sensor circuit(p0720) in general. i found the output shaft speed sensor connector was loose (connector lock was broken). i shoved it down tighter then test drove it. the light never came back on.------ dad and i then took a little road trip in the car. 4 hrs later D4 light started blinking again. i stopped and cleaned the connector out, and put die-electric grease on it. now it seems worse. usually it would take a few miles of driving before the light would come on. now it comes on just moving a few feet. -----we replaced the output shaft sensor with a known good one. now the connector lock works. still the D4 light blinks.....also seems to not shift into overdrive.....

i wonder if anybody has had a similar problem? or if someone could help....
please

 

your transmission is on its way out I would advise looking for a replacement. Honda autos are almost impossible to save once they start slipping. u can drain some atf and add some lucus no slip in it . it worked for me when I had an auto but I went to 5 speed because I was not being left stranded. When that transmission finally gives out its not going to move at all. just when its cold it may move a few feet and then feel like it has no gears and leave u stranded one day....

 

P1382 - Something is wrong with your CYP sensor.
P0700 - Automatic Transaxle (generic code)
P1753 - Lockup Control Solenoid A
P0720 - Countershaft Speed Sensor
P0730 - Shift Control System

Now, you need to buy/borrow/download the Factory Service Manual for your mother's car. Check sections 14-56, 14-68, and 14-75. Those are the diagnostic pages for the three transmission codes. Page 11-172 will cover your CYP sensor, while you're there.

Don't just throw away a transmission without doing any diagnostics first.