In my Blazer, the VIU and VCU are mounted together on a single bracket, and are easily removed as one unit. In order to do this, you will need to unplug the wiring harness and GPS antenna from the bracket, and unplug the cellular antenna from the VCU. Be careful with the GPS coax, apparently bending or creasing this wire can easily damage it. The cell antenna looks like it should screw off, but you actually just push the wire in while pulling back on the connector housing.
Once you get it out of the vehicle, you'll want to remove the VIU from the rest of the assembly. There are two rectangle connectors for the wiring harness that are easiest to remove if you pry back the clip with a small screwdriver. You will also have to unplug the GPS Coax. There are four phillips screws holding the VIU onto the bracket.
Now let's get the cover off this thing! The cover is only clipped on, and can be easily pried off using a small screwdriver. It should be fairly obvious when you take a look at it. Once you get that off, you will need to remove the three Torx (star) screws that hold the circuit board. You will also need to unbolt the GPS coax connector and remove the torx screw under the wiring harness connector. (See above image). Push the coax connector into the VIU housing, and you should be able to unfold the circuit board as shown below.
Now that we've got it open, the Oncore's location should be obvious. It's inside the metal RF shield that the antenna wire is hanging from. This shield will slide right off to reveal the Oncore.
| Disclaimer |