Head unit issue, OEM, sound option no control

Hello, I try to have every mechanical & electrical as stock as possible but im having this issue and I cannot think of any other answer than changing head unit to something else. If any of you had similar issue, please help.

I have mechanic shop myself, I'm ase certified as well but I feel useless because of this issue I have.

1) after changing battery to agm, my head unit turned it off itself, so i just turned it back on. Thought it has nothing to do with. Ever since then..

2) If I turn off the car when radio was on, when I turn my car back on, radio is on, of course.
Then after I turn it on, I hear buzzzzzzzzzing fan noise from behind the head unit.
a) If I change it to bluetooth, yes it connect to bluetooth, but once its connected I cannot control anything from sound option (where we control bass, travel.. etc)

3) If i turn off the car when bluetooth was on, when I turn my car back on, bluetooth is on, of course. Then after I turn it on, I don't hear buzzing fan noise; but I cannot connect to bluetooth until I do stop 2 above. (change it to fm radio, turn off the car, then turn it back on)

I scanned with my autel max and no problem at all wires, no issue found at all. Tried to reset, hard-reset, tried all kind of reset except Toyota's original obd hard reset.

I took it to local stupid Toyota dealer, paid stupid diagnose fee with dumb service adviser, they say its my amplifier issue, I didn't believe but I tried 2 different used amplifier, 2 different head units, all same issue. just different setting of "sound option" and its set to 1 setting, and I cannot change.

now what should i try, except changing head unit to something else aftermarket ?

 

Check your battery terminals and be certain they're tight. I had something similar happen to me. I even checked the terminals, and they seemed fine. It was when I actually put some man-juice behind the checking that I realized one of them was loose. Once tight, never had a problem since.

 

yea, just for incase, that was the 1st thing I did, ordered new agm battery again from my oem supplier and changed. deng it.

 

Do have a voltage booster? If not, an AGM battery might not be getting adequate charge.

 

Welcome. For shits n gigs man, throw a meter on the battery and see if it's not over outputting voltage. Humming in speakers is usually a power issue. Like if you run speaker wires next to your amp power cable you'll hear noise with the alternator spinning.

The radio may have an overload protection built in. I mean you're waiting on a new battery anyways

 

I already changed to new battery, over course I tight it right, checked voltage meter, even checked with my scanner as well. I don't have voltage booster, I don't have voltage issue either high or low. I don't have anything aftermarket products. Only except tires and suspensions everything is stock, have been using everything oem as well. sigh..

 

An AGM battery with the stock 4R alternator and no voltage booster is likely to have problems sooner or later.

 

i can change it to regular battery tomorrow, its not biggy here. but what else do you recommend to do after?

 

If it acts normal with a well-charged regular battery, that will help isolate the problem. AGM needs higher voltage out of the alternator to charge properly, so that battery may test as not fully charged. There are quite a few boosters on the market, and others here who use them can recommend better than I.

 

i sent one of my guy to pu regular battery and will be changed to regular oe rated battery today, will reset anything i would need, finish the drive cycle today. i will keep you posted if it works tomorrow. I hope it does. im sick of this bluetooth issue.