I have a 2005 sx 2.0. Yesterday while driving home I notice the speedometer fluctuating up and down while i was maintaining a constant speed... at the same time the trany downshifted to second and stayed there..the check engine light didnt come on even though i know it works as i have been dealing with the camshaft pos sensor code last month(p0340)..
anyways more about this problem. i removed the airbox to check the connectors on the trany.. all connection where tight and clean.. i did the key cycle to see if there was any codes and nothing came back on the dash so I plugged in the scanner to be safe and came back with 2 codes.. p0700 on the engine scan which refers to the trany.. and on the trany side code p0731 which is gear ratio error in 1st.. so i removed all the grounds and wire brushed and reconnected them. checked to make sure the input and output speed sensors showed good ground at the plugs.. and hooked everything back up.. cleared the codes and went for a test drive.. no I have no reading on the speedo and the trany still doesnt shift.. also the fuel gauge now goes from half full to empty when you accellerate..
As I said the grounds going to the input and output speed sensors are good.
Anyone got any ideas.. money is real tight as i was layed off from work and havent been able to find a new job yet so cant afford to send to the dealership to get fixed.. and I'm thinking maybe the sensors themselves but again if i buy and install them and it is not the problem i cant return them..

Any help is appreciated

 

just on update on this problem in case anyone else has it... spent 5 hrs last night going through 30 pages of threads looking for an answer it seems that no one came back on after the problem was fixed to say what it was and how it was solved...
every reply seemed to point to either the output speed sensor or wireing.. i had taken the ground leads that supply that section and the pcm off.. wire brushed them and re connected them.. used a tester and checked and got tone from the ground side of the plug (pin 1 dark blue wire with black stripe) to chassis ground so the ground wire was good and only read a .02 ohm resistance to the ground.. near perfect.. cleared the codes and started car.. as soon as i moved car in forward codes came back and no speedo.. talk to a transmission tech and he said basicly the same thing.. the speedo runs off the output sensor which also controls the shifting pattern.. he also said at the same time that output also works in tandom with the input sensor.. so if the input quits then the output will not work either even though there is nothing wrong with it.. so they should be changed as a pair.. i replaced both sensors,, reconnected wires,, cleared the codes and crossed my fingers.. same thing .. no speedo and no shifting.. I knew it wasnt the grounds and the sensors so either had to be the pcm or the feed wires to the sensor..
Long story short.. it was the feed wire right at the base of the ouput speed sensor.. because it was just inside the connector and the coating on the wire wasnt broken or even damaged i didnt suspect it but a quick test of the pin to the first 6 inches of wire showed no continuaty.. replaced the the connector and everything is working normal again...

Hope that helps anyone else with this problem

 

Ok so I'm having the same problem but my wiper blades also won't shut off. Not so much worried about that, but when you say you replaced the connector do you mean just the pigtail to the sensor?