2003 V6 Coupe w/Nav heat issue
 

I recently bought a 2003 V6 EX-L Coupe with Nav. The air con works fine on hot days but on cool days it still seems to blow cool air. I can get heat if I manually turn off the AC on the touch-screen, raise the temp to max then back it down to the mid 70 degree range.

I have tried the HVAC code DIY from PAhonda but it doesn't seem to work on my Nav unit.

Any ideas would be appreciated.

Thanks for reading through other threads before posting.

Here is a procedure from a shop manual linked in the online manuals thread in the DIY section. There is a link to this in the common diy thread on top of this page. Let us know if this works and I will change that post that you found earlier.

1.Turn the ignition switch ON (II).
2.Press the AUTO button and then the OFF button. Continue to hold both buttons down for 1 minute.

If there is any problems in the system, the temperature indicator will light up the segment (A through Q) 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 Q).

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.