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2010 Chevy Impala Radio Swap US8 – Fleet/Rental

I recently got a really good deal on a 2010 Chevy Impala from a rental company. Unfortunately it didn’t come with Bluetooth or the upgraded radio that is mp3 and XM satellite radio capable. I wanted to add an iPod hookup that displayed the song info on the screen, charged the iPod, and allowed for iPod control from the steering wheels. There are plenty of iPod modules for GM vehicles that can do this but they require the US8 GM radio that has Radio Data System (RDS) – to display the song information. Also, the only way to install add on modules to extend the radio’s capability, you need a XM wiring harness port. The easiest way to tell the difference is the right-most button on the programmable button line says CAT instead of a picture of a speaker (see below).

RDS General Motors radio with LCD that goes along entire radio and clock is always small in top-right corner – you can also tell this radio apart because it has “CAT” for category in right-most button of programmable buttons. Mine had part # 20756285. This radio is XM compatible and includes an extra plug in the back for the XM wiring harness:

Basic GM radio without RDS. LCD is large and in the middle with large clock – also, the right-most button has a speaker icon:

So the first project was to buy a US8 radio on eBay. Not just any radio that looks like the one above will work. You need to make sure it is pulled from a compatible vehicle. If you need help finding what GM RPO (like US8) option codes mean, you can reference this PDF: RPO Codes PDF

Reprogramming GM Radio – 2006+

Since 2006, GM has required the radio programming to match the VIN of the vehicle (as opposed to just needing an unlock code). To reprogram any electronic component on a GM vehicle you need a device called a Tech II programmer. These are expensive and so the only people that have them are dealerships, other repair shops, or your friend that is a GM mechanic.

If you want to know how to navigate your car’s computer with the Tech II, you can find all the possible settings on GM’s TIS website:

After the radio is programmed to your VIN it *should* work like normal. However, with mine it seemed to work normally at first, but the music wasn’t very loud at 50% volume, door chimes were very soft, and the equalizer only gave the options of Talk and Custom. From the TIS webiste, I found that there are two ways to program the equalizer setting with the Tech II:

GMLAN 29bit
Operating System

25865971 > 25909886 Part Number 25865971 “For use only in 4-door vehicles with Enhanced Audio system (RPO UQ3)”
25865972 > 25909887 Part Number 25865972 “For use only in 4-door vehicles with standard 6-speaker system (RPO UW6)”

Controller: RAD Radio
Audio System: MP3 Radio (RPO US8/US9)
Hardware: 20756285


After my dealership changed the Equalizer programming to the only other option, the radio volume and door chimes worked normally.

How to Get Factory Bluetooth + A2DP Music Streaming + iPod

Because my Impala was a rental, it had the option of “Delete Onstar”. That means the rental company saved money by removing Onstar. Unfortunately, the Onstar VCIM module contains the bluetooth component as well. The Onstar module is installed in the trunk on the driver’s side brake light. If Onstar was never installed in the vehicle, there is no wiring harness that runs to the top center of the back window for the Onstar GPS antenna or to the radio and computer components in the dash. Also, there is no microphone that is normally located in the roof, just above the rearview mirror. That means there is no way to put Onstar back in the vehicle. You can see a wiring diagram and other GM vehicle wiring diagrams here:

If the Impala had Onstar, but not bluetooth, getting factory bluetooth is possible with 2 options:

(1) Get a Costar Bluestar and replace the Onstar module in the trunk. Since Onstar is removed, you will no longer have it.

(2) Get a Onstar module (or VCIM) on eBay or use to locate a salvage yard – my part # was 25974806. eBay is more expensive and you can get lucky on pricing from salvage yards for around $50. When searching on, look for “Computer box not engine > Communication, (Onstar, opt UE1) voice recognition (opt UPF)”. If you replace your Onstar module with a salvage yard one, the VIN that is programmed to it won’t match. That means Onstar won’t work, but your bluetooth should. If you REALLY want your Onstar to work, it is possible, but a long road. You can visit this forum for examples of people that had success. You’ll also need to buy a bluetooth antenna if it didn’t come still attached. Its very short and just plugs in and is AC DELCO part # 15938939.

So if you’re looking for bluetooth that mimics factory controls and you never had Onstar, your search just got very limited. I found 2 acceptable ways to do this:

(1) A Parrot handsfree device. This integration requires some extra work to get it to work with the steering wheel controls and the controls aren’t very intuitive. You need to mount their small control panel on your dash. You can stream music through your phone’s bluetooth A2DP. You’ll also need to buy a separate wiring harness. This doesn’t help with iPod charging or RDS music display.

(2) The route I chose was a iSimple ISGM571 module that allows for 2 types of hookups: an iPod/iPhone cord and a separate iSimple Bluetooth iPhone module. This way, I can charge and display iPod song information on the radio. The iPod is also controlled through the steering wheel controls. The bluetooth module works with all types of phones, not just iPhones – this includes A2DP streaming, however, A2DP streaming does not display song information. It works flawlessly with my Evo 4G and Galaxy S2. The microphone quality is probably a 7/10 if Onstar factory bluetooth is 10/10. The only time people have trouble hearing me is 80mph on the highway. To see it in action, watch this video:


Overall, I’m very happy with the performance of the new radio, bluetooth, and iPod control. It keeps everything as close to factory controls as possible. The only exterior item that you see is the bluetooth microphone that is mounted on the ceiling by the mirror, but I’m the only one that notices that. Being able to answer calls and control the whole system from the steering wheel controls is what I was looking for. The bluetooth reconnects automatically when I get in the car and if I’m listening to my iPod and place or receive a call, the music is paused during the call as the call comes over the speakers and automatically resumes when I hang up from the steering wheel or phone itself. The only weakness of the bluetooth is that voice commands only sometimes work because it relies on the phone’s capability. I prefer to dial directly from the phone and everything integrates automatically.

I hope you found this post helpful. It took me about a month to learn all this piecing together information about which radio to get, how Onstar works, and which aftermarket system integrates the best.

13 thoughts on “2010 Chevy Impala Radio Swap US8 – Fleet/Rental

  1. You mean the ISGM571.  The ISGM575 is for the older Class 2 data system vehicles.  2005 would have been the last year for that system in the Impala.  Yours has the newer 29-bit LAN system, as referenced.  That’s the iSimple ISGM571.  It can be found at ReplacementRadios

    1. Thanks for the catch. Updated the post!

  2. Thank you, this saved me a ton of time. I am in the same exact situation.

    1. glad to hear!

  3. Huh, so if I already have the proper radio in my 2009 Impala (the US8) I can simply grab a $50 part from a local place and a $25 Bluetooth antenna and it will be effectively the same as a factory vehicle with the option (except that OnStar won’t work)?

    Where does the antenna plug in, to the module (I’ve only looked at mine once briefly)? What are the risks a person takes if they do this (I know the module does interface with other stuff in the car.)

    1. I’m not sure what parts you are referring to.

      The way I did it, I plugged the iSimple module into the empty satellite radio connector on the back of the radio. The iSimple bluetooth box connects to the iSimple module. Everything is controlled through the radio or steering wheel controls. If you go with something like a Parrot, it will still work, but I believe you lose steering wheel functionality without buying a special module that emulates GM functionality. Its cheaper to just go with the iSimple version.

      1. Sorry I was referring to the OnStar module with Bluetooth.

        1. I’m trying to remember, its been a while since I went through this process. They key with the Onstar w/ bluetooth method is having Onstar first. This is because you already have the necessary wiring and microphone built in to the ceiling that Onstar uses to communicate.

  4. Okay, so I already have the correct radio, factory onstar, and Bluetooth in my 2012 Impala. The thing is, the factory Bluetooth is A2DP or something where it will only do voice calls over Bluetooth. Audio streaming doesn’t work at all. Can I just buy the iSimple kit and use the auxiliary to allow changing the song, or is there something else I need? Also, is it difficult to get the iSimple adapter to fit behind the radio, or does it fit behind the glovebox pretty easily? I don’t want to take apart the dash or anything.

    1. The iSimple bluetooth module does support A2DP streaming. The screen on the factory radio will only say “STREAMING” when playing music. You don’t get artist and song info over bluetooth like you do with the ipod cable. The steering wheel controls for pause and skip back/forward do work over bluetooth.

      It’s been a while since I did this. If I remember correctly, the iSimple box plugs in with a patch cable and emulates its bluetooth/ipod functionality using the satellite radio button.

      Install is pretty simple: pop off the brown wood (or metallic) bezel that surrounds the radio and HVAC controls; it is held on by clips. Then take out the screws to slide the radio out. You can access everything from there and there is plenty of room to place the iSimple box.

      Worst case, just use the link in this post to buy both the iSimple harness and iSimple bluetooth on amazon (you aren’t required to hook up bluetooth microphone if you don’t want). If it doesn’t work the way you want, return it for free. You can test everything with the radio still plugged in and unbolted from the dash.

      1. Thank you so much! One other question. I have an iPhone 6 so the iPod plug won’t fit my phone. Is there a USB auxiliary cord I could buy to use instead or buy a different iSimple kit altogether?

  5. Update: I bought the iSimple ISGM 651 for my ’12 impala (It has factory onstar and Bluetooth). I hooked it up no problem and was able to get the USB hookup to work as well as the Bluetooth built inside the iSimple. Since I already have Bluetooth factory installed, when the phone rings, the factory one will pick it up after a few seconds. It’s a little glitchy at times but it works. My phone will pair with both the iSimple and the factory Bluetooth at the same time, and I love it!

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