What has caused my water inlet pipe feeding the ice making machine to freeze?

You could try pipe insulation. This is 1\4" but it is available for most pipe sizes.

https://www.google.com/search?q=1%2F4+pipe+insulation

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First, I'm not a Frigidaire representative.
*Check your warranty. You should call vendor for service.
* Note; Check as refrigerators usually have long warranty.

*** The following is for information only.**
* First check if the water faucet (valve) is turned on.
* first check if you have water from the water dispencer. No? then there is a clog. (note; older GE fridge) ; https://www.youtube.com/watch?v=cjShdHoiiJw
* He suggest checking filter then the water solenoid. (requires getting into the guts of box. (may void warranty.)
* Check if the filter is seated and locked. https://www.youtube.com/watch?v=9x4Q_k9czzU
* Change filter (if stuck); https://www.youtube.com/watch?v=yeWmjDO-kZI
* Water okay? Then check Ice maker; Perform "Harvest Test"; https://www.youtube.com/watch?v=LQQHNHHM4QE
* Not "Harvesting"? (not running) ; https://www.youtube.com/watch?v=LQQHNHHM4QE
* Another "Replacement" of ice maker; https://www.youtube.com/watch?v=v0kh3RVcNZo
* Good example of "freeze up"; https://www.youtube.com/watch?v=KsV-Zno92Fk
*** For older models:
* I've had this problem a lot with my old fridge. Water line works but no ice.
* Check if the "Ice Full" leaver is in the down (no ice) position. Some ice makers will lock the leaver (a stiff wire) in the full position to manually shut off ice maker. Make sure it swings up and down when ice tray is empty.
* Sometimes when the tray is left full of ice for a week or more then the tube feeding water will freeze up. Defrosting the freezer on a regular basis will help. A quick fix is to pour warm water in the ice maker section (where the ice is formed). This will help melt the clogged pipe and also make some ice while your waiting. You may have to do this several times. But at least you have ice.
* This (freezing up) may also be caused by the freezer set too cold. The temperature dial should be in the middle. But turning it colder and colder over time will cause ice to build up and prevent foods from freezing properly (thus turning the dial down colder.) Once your maxed out on the dial. You will find the freezer gets warm and things get covered in frost crystals.
* Transfer food to another refrigerator and perform a complete defrost by leaving it unplugged and the door open (freezer section).
* Frequently check and dump water at bottom of fridge. Clean the dust on coils while down there.
* A fan blowing into the freezer section helps. (Do NOT use a heated fan as it will warp the plastic and over pressure the refrigerate.)
* Once defrosted (+4 hours). Power up the freezer and set the temperature dial to mid point and the freezer diverter to middle or normal setting. Don't put the food back in yet. Wait till the freezer gets down to normal freeze temp (about 0 to 10F)
* Move freezer back in place (if you moved it to access plug) then slowly put back the food. Try not to cram stuff in. Leave space for air to flow freely around items.
* Final, Call for service anyway and have them perform yearly service. Check your warranty.
Aloha, ukeboy57

*Check your warranty. You should call vendor for service.
*** The following is for information only.**
* I've had this problem a lot with my old fridge. Water line works but no ice.
* Check if the "Ice Full" leaver is in the down (no ice) position. Some ice makers will lock the leaver (a stiff wire) in the full position to manually shut off ice maker. Make sure it swings up and down when ice tray is empty.
* Sometimes when the tray is left full of ice for a week or more then the tube feeding water will freeze up. Defrosting the freezer on a regular basis will help. A quick fix is to pour warm water in the ice maker section (where the ice is formed). This will help melt the clogged pipe and also make some ice while your waiting. You may have to do this several times. But at least you have ice.
* This (freezing up) may also be caused by the freezer set too cold. The temperature dial should be in the middle. But turning it colder and colder over time will cause ice to build up and prevent foods from freezing properly (thus turning the dial down colder.) Once your maxed out on the dial. You will find the freezer gets warm and things get covered in frost crystals.
* Transfer food to another refrigerator and perform a complete defrost by leaving it unplugged and the door open (freezer section).
* Frequently check and dump water at bottom of fridge. Clean the dust on coils while down there.
* A fan blowing into the freezer section helps. (Do NOT use a heated fan as it will warp the plastic and overpressure the refrigerate.)
* Once defrosted (+4 hours). Power up the freezer and set the temperature dial to mid point and the freezer diverter to middle or normal setting. Don't put the food back in yet. Wait till the freezer gets down to normal freeze temp (about 0 to 10F)
* Move freezer back in place (if you moved it to access plug) then slowly put back the food. Try not to cram stuff in. Leave space for air to flow freely around items.
* Final, Call for service anyway and have them perform yearly service. Check your warranty.
Aloha, ukeboy57

Possibly the inlet valve.  If it doesn't shut all the way off it will drip water which will freeze in the chute and cause it to overflow.  

Pour about 2/3 cup of water into the ice maker . If it freezes and dumps the cubes , but doesn't fill with water , replace the water inlet valve ( the piece that the wall water line connects to on the fridge ) . Also check to be sure that the fill tube from the back of the freezer to the ice maker , isn't blocked with ice , as this is caused by a seeping bad water valve . If the ice maker doesn't dump the cubes , after freezing , then replace the ice maker . Also check to make sure the coils under the front of the refrig , are clean of dust , lint , pet hair , etc.

Check for ice blockages at the water inlet pipe of the ice maker.

Hello,

If your trying to save a service call you have your work cut out for you. The ice maker is a unit that sits by itself attached to the wall or part of the freezer wall.

There are many reasons why you do not get ice and I will list them.

1- Temp of freezer got too cold and has frozen the pipe that feeds the water to fill the icemaker.
check to see if the icemaker has any ice in the area that fills and makes the cubes.
If the pipe is clogged, very gently put a small tipped screw driver in the fill hose that sites over the ice making row in the ice maker. Be careful you do not push your screwdriver out the back of the refer.
Check to see the freezer temp is not too cold and is freezing that pipe. 0-3 degrees F is good.

2.- check to make sure your water feeding the fridge is on. There is an on off valve to allow the water to feed the icemaker when it needs to fill. This could be bad. there are reset proceedures for the fridge, but unplugging the entire frige for 1 minute and plugging it back in you can listen for the the valve to come on and see if it fills the ice maker resevoir.

3. If it fills and freezes the ice resevoir, then the sensor in the ice tray does not sense the frozen ice and will not cycle and kick cubes. At this point, unless you are super tech, you will need to replace the entire icemaker unit.

Hope this helps.

ice makers have a bar that urns the ice maker on and off. look in your ice maker and make sure the bar is still in the on position.

replace the optics board