I20 2011 model. air blow mode knob faulty. how to set apart and replace with

HAVC Blend Door problem under the dash

I do not know this car so iam guessing in the dark here but look for a vacumn pipe from the manifold going into the car somewhere,sorry here but no experiance of this model car

sounds to me as if one of the doors / air mix door stuck. your model sentra had some issues with that. we were actually removing the dash and complete evaporator box and replacing the air mix door foam that came of and jammed the doors. it also could be that your cable came off that connects from the knob to the evaporator box to switch modes. does the knob on dash turn or is it stuck??when you turn it??let me know.

replace the blower motor resistor located on the passenger side under the dash around the blower motor

depending on model and year even though it is manual a/c most of them do not have cables anymore and are all controlled by electric circuit board.i have seen this problems in early model highlanders and some lexus models.i have been successful but not every time in taking the unit out and taking it apart to repair the wire that has broken from the switch getting loose and moving back and forth every time you adjust the temp control.the wire is a type of ribbon like computers have and is stiff,that is why it will break so easy when the switch gets loose......i hope this info will help and if you need more info let me know.........the unit itself is not that hard to replace and if you do take it out and take it apart and see the problem a good radio shop that repairs radios might could help you........i would be afraid of a used one since this problem is out there.........let me know how you did and if i helped you any.........

The LH models (LHS, Concorde, New Yorker, Intrepid, Vision) do have self-diagnostic capability with the standard type heater controls. I don't know about the Sebring heater controls (my '95 manual doesn't mention it) but if you have the various controlknobs/buttons that I will describe you could give it a try.
There is a rear window defogger that is initiated by a push button with an LED light. That light is the readout, by its blinking. To begin the diagnostic mode, run the vehicle at idle with the controls set as follows: the blower speed knob should be on any position other than OFF, the temperature knob should be set in full COOL, and the mode knob should be set on Defrost mode.
To enter the diagnostic mode, press the defogger switch in for five seconds, until it begins to blink, then release it. It will continue to blink for about 30 seconds while it calibrates. If it goes out, the calibration is OK and you can skip 3 paragraphs to "Position...mix mode" below.
If the light stayed on, switch the mode knob to the MIX (defroster-floor) position. If the light stays on there is a problem with the control head unit.
Switch the mode knob to the FLOOR position, if the light stays on, it indicates a problem in the blend door or the blend door actuator wiring.
Move the knob to the Bi-level (panel-floor) position where a continuous light indicates a problem with mode actuator or circuit.
Position the knob in the MIX mode. The LED light should now flash twice then pause, and continue a two-flash sequence, indicating that the MIX mode is OK.
In the FLOOR mode the light should flash three times, meaning that the FLOOR mode is OK.
In the Bi-Level Mode, a four-flash sequence indicates that mode is OK.
In the PANEL mode the light should flash 5 times to indicate no problems there, and in the recirc-panel mode 6 times and seven times in the recirc Bi-level mode.
The temperature control can be checked by switching the mode knob to Defrost and rotating the temperture knob. If the temperature contol is OK, the light will flash faster the more you turn the temperature knob up, until the light goes out at the hottest setting.
Switch the knob between Panel and Recirc-Panel and watch the recirc door (unit under the dash). Proper operation means that circuit and components are OK.
To get out of the self-diagnostic mode, turn off the blower or push the air conditioning button once.
If this doesn't seem to apply to your control head or you get no response from an LED light for the rear defroster, then the Sebring may not have this capability. Please let me know your results if any

I would first remove the fuse for the heater control head for one minute and then put in and retry.
The control head could have locked up on you with a volt spike. The rear defrost switch does not go through the same circuit in the heat as the hvac controls. Could be a broken know also.
Could also be mechanical linkage on side of heater box above accelerator pedal may have broken or popped apart. or if electrical motor control may be actuator.

#76-11-01: HVAC CONTROL KNOB SPINS FREELY (REPLACE) - (Oct 9, 1997) SUBJECT: HVAC CONTROL KNOB SPINS FREELY (REPLACE ALL THREE KNOBS)
MODELS: 1996-97 CHEVROLET AND GMC M/L AND G VANS 1995-97 CHEVROLET AND GMC C/K TRUCKS
CONDITION:
SOME CUSTOMERS MAY REPORT THAT ONE OR MORE HVAC CONTROL KNOBS SPIN FREELY, RESULTING IN LOSS OF FAN, TEMPERATURE AND/OR MODE OPERATION.
CAUSE:
THE KNOB'S PLASTIC INNER SHAFT MAY CRACK WHEN FORCED AGAINST ITS STOP.
CORRECTION:
IF ANY ONE OF THE THREE HVAC CONTROL KNOBS EXHIBITS THIS CONDITION, REPLACE ALL THREE KNOBS WITH NEW P/N 16268157.
PARTS INFORMATION:
P/N DESCRIPTION QTY 16268157 KNOB, HVAC CONTROL 3

1. what year model is accord?
2. there are several doors in the air box
3. blend door (hot cold)
4. mode door (defrost, floor, vent)
5. recirculation door (outside air)
6. if the control mechanism is defective. the tech may have reached under the dash and manually opened the blend door.
7. which control knob does not work mode or temp?

if it has dual zone climate setting it could be stuck in the cool setting. if it is not blowing any air it could be the duct came loose and it is blowing the air inside the dashboard. it will require you to pull the dash apart to inspect what the exact cause is. it could be anything from a bad temp setting switch in the climate control panel to a bad vac line that that switches the air from hot to cold. any other info you could give me may help such as if it is full electronic climate or manual knobs, dual zone, is it blowing any air or just no hot air.

You need to replace the blower speed module.