[goatman70]

2002 Ody exl
when I select defrost the AC turns on (normal) and nothing comes out of the window defrost vents. The side vents blow just fine.

Any ideas - I searched for threads and didn't find much on this to remedy the situation

Thanks - great forum. Have used it multiple times with my 2 odys.

 

[New Dad New Van]

You can retrieve HVAC DTCs from the control panel. This will tell you the problem area.

It sounds like a problem with the Mode Control Motor and its circuits or the linkages and doors to this motor are stuck. If this is correct then you will be getting a DTC of "L" or "M".

How to Retrieve a DTC
The climate control unit has a self-diagnosis function.
To run the self-diagnosis function, do the following:
1. Turn the Ignition switch ON (II).
2. Press the AUTO button and then press the OFF button. Continue to hold both buttons down for 1 minute.
If there is any abnormality in the system, the temperature Indicator will light up the segment (A through N) corresponding to the error. The temperature
indicator will then alternate every second between displaying ‘‘88’’ (all segments lit) and the error code segment (A through N).
NOTE: The system will only display the DTC when the AUTO and OFF buttons are pressed. If you release the buttons, the display will go blank. To return the display, simply press the AUTO then the OFF buttons again.
To determine the meaning of the DTC, refer to the DTC Troubleshooting Index. If there is no abnormality, the segment will not light up.
Cancelling the Self-diagnosis Function
3. Turn the ignition switch OFF to cancel the selfdiagnosis function. After completing repair work, run the self-diagnosis function again to make sure
that there are no other malfunctions.
To retrieve the DTC , you must run the self-diagnosis function. In the case of multiple problems, the respective Indicator segments will come on. If Indicator segments A, C, E, G, I, and L come on at the same time, there
may be an open circuit in the common ground wire of the sensors.
A An open in the in-car temperature sensor circuit
B A short in the in-car temperature sensor circuit
C An open in the outside air temperature sensor circuit
D A short in the outside air temperature sensor circuit
E An open in the sunlight sensor circuit
F A short in the sunlight sensor circuit
G An open in the evaporator temperature sensor circuit
H A short in the evaporator temperature sensor circuit
I An open in the air mix control motor circuit
J A short in the air mix control motor circuit
K A problem in the air mix control linkage, door, or motor
L An open or short in the mode control motor circuit
L A problem in the mode control motor circuit
M A problem in the mode control linkage, doors, or motor
N A problem in the blower motor circuit

 

[goatman70]

I will give it a whirl - thanks for the information. Much appreciated. Sounds like I may need to take it in to the dealer

 

[goatman70]

ran the test - got 88 flashing with no code.
started the car - put on auto mode and then I selected the defrost and air was blowing pretty well out of the windshield defrost. Strange

when I needed it in the cold chicago night before - nothing was coming out. Things seem to be well now. My clock light is out - I have all the great pictures to do that job thanks to this forum. Great job - there are a lot of folks on here pretty smart. Learn something new everytime I log on here

 

[ralbach]

ran the test - got 88 flashing with no code.
started the car - put on auto mode and then I selected the defrost and air was blowing pretty well out of the windshield defrost. Strange


As I saw this and tried it in 2018 I thought to follow up with a similar experience. Just the act of running the diagnostics seemed to improve the defrost output.

But as we say in the tech industry. Problems that go away by themselves return the same way.