Will transmission speed sensor on 03 infinti fx35 stop the car from shifting gears

The transmission shifts with different gears with different fluid pressures controlled with the mass airflow sensor.MAS sensor,,this could be the problem or air filter blockage.

99 00 01 02 03 FORD F150 MANUAL TRANSMISSION 5 SPEED MAZDA-TOYO KOGYO 4X2 8 CYL

will it shift if you double clutch ?

might be a shift linkage adjustment
internal shift fork has broken a scroll pin

clutch fork movement ok ?

That code relates to the transmission:
It's the sensor that sits directly on top of the transmission case.. Easy fix.
This sensor detects the rotation speed of the direct clutch drum.
By comparing the direct clutch speed signal with the vehicle
speed sensor signal, the ECM detects the shift timing of the
gears and appropriately controls the engine torque and hydraulic
pressure in response to various conditions, thus performing
smooth gear shifting.
DTC No. DTC Detecting Condition Trouble Area
P1705
The ECM detects conditions (a), (b), (c), (d), (e) and (f) continuity
for 4 secs. or more.
(2?trip detection logic)
(a) Vehicle speed : 32 km/h (20 mph) or more
(b) 3rd or 4th gear
(c) NC2 < 300 rpm
(d) Park/neutral position switch: OFF
(e) Solenoid valves and vehicle speed sensor are normal
(f) L position: OFF
 Open or short in direct clutch speed sensor circuit
 Direct clutch speed sensor
ECM
WIRING DIAGRAM
DI02P?03


according to this site:
Error code P1705

It's not why your car won't start.

No one can tell you what it is.This is the operating characteristic of your transmission and customer do object to the noise or clunk and dealer discourage the repair. This is TSB 03-07-29-004G. Let me give you a partial copy. INFORMATION
Bulletin No.: 03-07-29-004G
Date: December 15, 2010
Subject: Manual Transmission Operating Characteristics
Cold Operation
Manual transmission operation will be affected by temperature because the transmission fluid will be thicker when cold. The thicker fluid will increase the amount of force needed to shift the transmission when cold. The likelihood of gear clash will also increase due to the greater time needed for the synchronizer assembly to perform its function. Therefore when the transmission is cold, or before it has reached operating temperature, quick, hard shifts should be avoided to prevent damage to the transmission.
Backlash
Backlash noise is created when changing engine or driveline loading. This can occur when accelerating from a stop, coming to a stop, or applying and releasing the throttle (loading and unloading the driveline). This will vary based on vehicle type, build variations, driver input, vehicle loading, etc. and is created from the necessary clearance between all of the mating gears in the transmission, axle(s) and transfer case (if equipped).
Shift Effort
Shift effort will vary among different style transmissions and synchronizer designs. Usually the more heavy duty the transmission, the higher the shift effort because of the increased mass of the components. Shift effort can also be higher in cold weather because the fluid will be thicker. Medium duty transmissions will not shift as quickly as a Corvette transmission. To reduce shift effort, do not attempt to rush the shift - allow the synchronizers to work as designed. Shifting harder will only increase the chance of rushing past the synchronizer leading to grinding while shifting.
Non-Synchronized Gears
Some light duty truck transmissions in 1st gear (creeper-gear) and reverse gears in various transmissions, along with all gears in some medium duty transmissions, may be non-synchronized. This means there is not a mechanism to match input and output shaft speeds to allow for a smooth shift. This function is left up to the driver. This can be noticed if a shift into 1st or reverse is attempted while the vehicle is rolling or before the input shaft stops rotating leading to a gear grind. The grinding can be reduced by coming to a complete stop and pausing for a moment before shifting into the 1st or reverse gear. Some slight grinding can be expected. In medium duty non-synchronized transmissions, the driver must match input shaft (engine) speed to output shaft (driveshaft) speed with every shift. This can be accomplished by double clutching, or by using other methods. If the driver is not able to perform this function properly, there will be gear grinding with each improperly completed shift. Driver training may be required to correct this condition. Clutch brakes are used in medium duty non-synchronized transmissions to allow a shift into gear at a stop. The clutch brake is used to stop the input shaft from spinning, allowing a shift into gear at a stop without grinding. The clutch brake is activated by pressing the clutch pedal all the way to the floor. When the clutch brake is used, it is possible to have a blocked shift with the vehicle stationary. If this occurs, engage the clutch slightly to rotate the input gear to allow the shift. The clutch brake is intended to only be used while at a stop. Care must be taken to not activate the clutch brake while shifting between gears. This could lead to excessive grinding or a blocked or missed shift.

It would not be an O2 sensor. What is the code your scanner is pulling?

you need to take this to dealer for repairs,there might be a short in the speed sensor wires that did that to your speedometer,the reason it won't shift is speed sensor,input sensor or output sensor on transmission.

Hi:
This same thing happened to my daughter,s car, and it ended up being fixed with a transmission speed sensor. This sensor not only runs the speedometer, it helps tell the transmission when to shift too.

Hi,
The reason the speedometer stopped working would be the speed sensor.
Sounds like the vehicle speed sensor is not working or the gear on it is stripped. If you look at the rear housing of the transmission, you will see a black plastic sensor protruding from it with a two wire connector and the speedometer cable attached to it. The sensor might be coming apart or the gear that is driven off the output shaft is stripped. The speed sensor, along with the governor, tells the transmission when to shift. You can remove the sensor by simply taking out the bolt that holds it in. A small bracket around the sensor is secured by this bolt. Carefully look at the nylon gear to see if it is worn through the middle.
Thank You for using Fixya.com

Do you know if you have a 3 speed trans or a 4 speed trans? If it is a 4 speed , the (D) on the shift indicator will have a box around it. I need to know which transmission you have, then I can help.

On a lot of vehicles there is a transmission speed sensor that receives data that tells it how fast the car is going and shifts accordingly. If this sensor is bad the transmission can't function properly. I would have this checked, they are not that terribly expensive, and not that hard to change on most vehicles. Hope this helps.