2004 Impala Stereo Steering Wheel Controls Wrong Functions

When I first bought my car, I had an after market radio installed in my car. I had the shop install an infrared setup that used my stearing wheel controls and sent infrared out to the after market radio. It's been about 5 years now and the after market radio is starting to mess up. I bought another factory radio and put it back in. The aftermarket radio is out now. I had the dealer remove the anti-theft from it. Everything is good except my steering wheel controls don't work right anymore. My volume buttons now change the channel. The channel button up button went through the presets. The rest of the buttons I don't think does anything.

The shop that installed my stereo went out of business so I can't take it back to them to undo what they did. Does anyone know how to fix it and get the functions back to the way they were so the volume buttons control the volume, the station buttons control the stations, etc?

The steering wheel control schematic shows that there are only two wires that connect to and control the steering wheel radio functions. One is a pink colored wire controlling the volume side button. A dark blue wire controls the seek/scan side buttons From what you described, it sounds like someone conected these in reverse order somewhere between the steering wheel and the radio resulting in the problem you are having. I myself have never had this problem, but I dont see how any other wiring error or malfunction could possibly cause this. It should be simple to fix. Hope this helps.

There's at least 4 more buttons on the steering wheel for the radio... the mode button, mute, preset stations button, and i can't remember the rest... so there should be more wires.

I agree it would seem like there should be more wires--- but according to the schematic there isnt. The volume/mute side is controlled by one wire and each of the other buttons on that side with the volume button is controlled by a set of resistors being fed by that one wire from the radio. The exact same scenario is true for the channel up/dowm preset side using only its one wire from the radio. This circuit on each side (which is in the steering wheel) appears to be identical allowing it to work in reverse order as you are experiencing.

Here are some additional details regarding which wire controls what button

Dark blue controls seek up,seek down, seek type, preset

Pink controls mute,volume up, volume down and mode

They're not backwards though (button wise.) The volume does control the channels. But the down channel button goes through the presets... it doesn't control the volume. I don't know off the top of my head what the rest do.

when I get in there, I'll have to look for those color of wires coming out of the steering wheel. My guess is they had to put a module of some sort. I should be able to find it easily by following the IR emitter. Then whatever is going in and out of that, I should just be able to splice the wires and put colors back together to get rid of whatever box they put in place. When I put the radio back, I wasn't looking at this part at all. I just wanted to make sure the radio worked first. I'm probably just over-thinking this. I just need to open the dash up and look at it.

There is a good reason for that-- although the circuitry is identical on each side the specific value of the resisters used on each side is different. As a result, each side should be working if the wires were reversed but not working quite correctly--- as you noted.

Just a thought- if you open up the dash I'd be looking for those two wires coming from the radio and trace them back visually to the steering wheel. I'll bet you'll find them plugged in or spliced in reverse order. Good luck.

Ok, so I just got done ripping apart my dash again. I found the module the shop put in. It doesn't look like anything really was wired wrong other than they spiced their module into it. But the colors matched up on the other side and weren't reversed. There were 3 wires though. I don't remember what color they were. But I took their module out and put the wires back color to color and the steering wheel controls work perfect now.

Thanks everyone!!

Dorlow, The Steering wheel controls work on Resistance (its how they all work on 2 wires). With the aftermarket module in there, it was messing up the expected resistances when certain buttons were pressed. thats why it works correctly now that you've removed it! :biggrin: