My 04 NON NAV tl's cd changer broke, so I replaced the radio with a unit for an 05 that's for a NAV unit. The wiring harness for the NAV and NON NAV are the same. Everything works well except that I can no longer access my HFL through the steering wheel button. Any of you know what may be the problem. My Acura dealership did the replacement and they believe that the incompatibility may be due to the NON nav car with a NAV car radio.

 

I'm going to answer my own question. The NON Navi car needs an NON Navi radio, The wiring harness in the back of the radio appears to be the same as the radio for a Navi car but the steering wheel voice command button will not work properly.

 

if you have an 04, you must use a 04 radio. 05 are different. best way to check is there is a 4 digit code by the cd load slot.

 

the 4 digit code is for the firmware version on the radio itself. The radio for 2005 just had different logic for the rear speakers. the radio will work fine, but your HFL will not since the radio logic for the non-navi and navi ones are different since the navi handles some part of the HFL.

 

different firm wear, is also different radio version.