my wife has a 2009 Acura TL SH-AWD with Tech Package...her defrost stopped working, we get heat out of the front facing vents SOME heat out of the foot vents, and it seems like both of the vents in the back seat work fine...

I did the self diagnoses process (turned on the key, held the on/off button and pressed the rear/mirror defrost button 5 times within 10 seconds) and I got the Auto 88 defrost error...

does anyone know what the likely causes are, and how do I fix them?

 

I have the Exact same problem! Same Car, I see nobody responded to your question have you found the problem yet by chance? I sure don't want to pay the $155 just for diagnosis....
anyone please?