Faceplate is not displaying anything.Knobs are ligthing up but no display.What could be wrong?

1) Turn on the car.
2) The faceplate rotates out and the CODE - - - - prompt appears.
3) Press >>' and Auto keys simultaneously on the faceplate and hold for 4 seconds. (If the faceplate rotates back into the console push on the upper left top edge of the faceplate and it will flip back around. Press the Eject button and then try it again.)
4) The screen will still say CODE, but the - - - - will disappear! When this happens press the 5 key on the remote twice and it enters a K on the display on the faceplate. Hit the >>' key on the faceplate.
5) Press the 2 key on the remote three times and it enters a C on the display on the faceplate. Hit the >>' key on the faceplate.
6) Press the 2 key on the remote once and it enters an A on the display on the faceplate. Hit the >>' key on the faceplate.
7) Press the 7 key on the remote twice and it enters an R on the display on the faceplate. Hit the >>' key on the faceplate.
8) The radio goes into All Off mode and you are set! Hit the SRC button on the faceplate to select CD, Radio, etc.

Go online with make and model and search or go to the TORO web site or find a local service centre and ask there.

For this fix you need to reconnect your battery.
1) Turn on the car.
2) The faceplate rotates out and the CODE - - - - prompt appears.
3) Press >>' and Auto keys simultaneously on the faceplate and hold for 4 seconds. (If the faceplate rotates back into the console push on the upper left top edge of the faceplate and it will flip back around. Press the Eject button and then try it again.)
4) The screen will still say CODE, but the - - - - will disappear! When this happens press the 5 key on the remote twice and it enters a K on the display on the faceplate. Hit the >>' key on the faceplate.
5) Press the 2 key on the remote three times and it enters a C on the display on the faceplate. Hit the >>' key on the faceplate.
6) Press the 2 key on the remote once and it enters an A on the display on the faceplate. Hit the >>' key on the faceplate.
7) Press the 7 key on the remote twice and it enters an R on the display on the faceplate. Hit the >>' key on the faceplate.
8) The radio goes into All Off mode and you are set! Hit the SRC button on the faceplate to select CD, Radio, etc

To reset the code do the following:
1) Turn on the car.2) The faceplate rotates out and the CODE - - - - prompt appears.3) Press >>' and Auto keys simultaneously on the faceplate and hold for 4 seconds. (If the faceplate rotates back into the console push on the upper left top edge of the faceplate and it will flip back around. Press the Eject button and then try it again.)4) The screen will still say CODE, but the - - - - will disappear! When this happens press the 5 key on the remote twice and it enters a K on the display on the faceplate. Hit the >>' key on the faceplate.5) Press the 2 key on the remote three times and it enters a C on the display on the faceplate. Hit the >>' key on the faceplate.6) Press the 2 key on the remote once and it enters an A on the display on the faceplate. Hit the >>' key on the faceplate.7) Press the 7 key on the remote twice and it enters an R on the display on the faceplate. Hit the >>' key on the faceplate.8) The radio goes into All Off mode and you are set! Hit the SRC button on the faceplate to select CD, Radio, etc.
For further assistance please let me know.

Without test...

To reset the code do the following:

1) Turn on the car.
2) The faceplate rotates out and the CODE - - - - prompt appears.
3) Press >>' and Auto keys simultaneously on the faceplate and hold for 4 seconds. (If the faceplate rotates back into the console push on the upper left top edge of the faceplate and it will flip back around. Press the Eject button and then try it again.)
4) The screen will still say CODE, but the - - - - will disappear! When this happens press the 5 key on the remote twice and it enters a K on the display on the faceplate. Hit the >>' key on the faceplate.
5) Press the 2 key on the remote three times and it enters a C on the display on the faceplate. Hit the >>' key on the faceplate.
6) Press the 2 key on the remote once and it enters an A on the display on the faceplate. Hit the >>' key on the faceplate.
7) Press the 7 key on the remote twice and it enters an R on the display on the faceplate. Hit the >>' key on the faceplate.
8) The radio goes into All Off mode and you are set! Hit the SRC button on the faceplate to select CD, Radio, etc.

Source: http://techbybucky.blogspot.com/2008/01/how-to-reset-security-code-on-kenwood.html

Good luck.

Please check if the connector of the faceplate and head unit don't have dirty or bended pins, these can produce false contacts between them and can produce fails as the one you have, if this is OK, maybe you have a bad faceplate or head unit.

You will need a Kenwood RC-410 remote control.
To reset the code do the following:

1) Turn on the car.
2) The faceplate rotates out and the CODE - - - - prompt appears.
3) Press >>| and Auto keys simultaneously on the faceplate and hold for 4 seconds. (If the faceplate rotates back into the console push on the upper left top edge of the faceplate and it will flip back around. Press the Eject button and then try it again.)
4) The screen will still say CODE, but the - - - - will disappear! When this happens press the 5 key on the remote twice and it enters a K on the display on the faceplate. Hit the >>| key on the faceplate.
5) Press the 2 key on the remote three times and it enters a C on the display on the faceplate. Hit the >>| key on the faceplate.
6) Press the 2 key on the remote once and it enters an A on the display on the faceplate. Hit the >>| key on the faceplate.
7) Press the 7 key on the remote twice and it enters an R on the display on the faceplate. Hit the >>| key on the faceplate.
8) The radio goes into All Off mode and you are set! Hit the SRC button on the faceplate to select CD, Radio, etc.

Obviously, safety first. This being an electrical fix, unplug or otherwise disconnect the power to the appliance.
A philips screwdriver and 1/4" nut driver(or socket) are all that's needed.
First, there are 8 fasteners on the underside of the control panel. Only the 4 nearest the oven openning need to be removed from here.
Next, remove the burner knobs for the stovetop(simply pull straight off; if stuck, wrap a folded wash cloth behind the knob to gain extra leverage). Then remove the 4 screws that were behind the knobs.
At this point the panel should be loose and pulling out the bottom of the control panel will allow it to clear the knob shafts. Be careful not to pull too far, as the wires to the control board are rather delicate.

Change the flat cable that connects the faceplate with the mainboard sometimes is broken.

you need a remote for the KDC-MP628 for this to work.

1)Press >>| and Auto keys simultaneously on the faceplate and hold for 4 seconds.
2) The screen will still say CODE, but the - - - - will disappear! When this happens press the 5 key on the remote twice and it enters a K on the display on the faceplate. Hit the >>| key on the faceplate.
3) Press the 2 key on the remote three times and it enters a C on the display on the faceplate. Hit the >>| key on the faceplate.
4) Press the 2 key on the remote once and it enters an A on the display on the faceplate. Hit the >>| key on the faceplate.
5) Press the 7 key on the remote twice and it enters an R on the display on the faceplate. Hit the >>| key on the faceplate.
6) The radio goes into All Off mode and you are set! Hit the SRC button on the faceplate to select CD, Radio, etc.