Radio throwing codes?
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2nd Gear
Joined: Nov 2018
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Radio throwing codes?
2005 c6 is throwing codes. I went to turn her on and it didnt read my gas guage said it had low fuel but I had a 3/4 tank. Also threw service vehicle soon, check engine light, service antilock brakes, and shocks inoperative.
it has an after market radio in it and the dealership is pretty adamant about it being the radio and want to put the stock back in to see if the codes clear. I also brought up the ecm possibly being it and the guy says he isnt even worried about that right now because he thinks it's the radio.
She drove fine. She was out in some rain two days before it happened but drove fine one day and then that the next. I did get the rear drivers side wheel replaced since it had a crack but that is probably unrelated.
I cant find any forums pointing to an aftermarket radio causing problems and would like to know what you guys think before dropping the money to have them swap it just to have it end up being something else.
it has an after market radio in it and the dealership is pretty adamant about it being the radio and want to put the stock back in to see if the codes clear. I also brought up the ecm possibly being it and the guy says he isnt even worried about that right now because he thinks it's the radio.
She drove fine. She was out in some rain two days before it happened but drove fine one day and then that the next. I did get the rear drivers side wheel replaced since it had a crack but that is probably unrelated.
I cant find any forums pointing to an aftermarket radio causing problems and would like to know what you guys think before dropping the money to have them swap it just to have it end up being something else.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,644
Likes: 4,082
From: Cape Coral, Florida
Hi !!...what codes are the car throwing ??...”U codes” maybe ??...yes, an aftermarket radio can sometimes cause issues on your CAN data line and cause all kinds of electrical issues...C6’s have a Class 2 and a GMLAN...sometimes some of the car’s modules can even keep the car from starting. I have a C5 and seat modules or BCM’s that are defective due to water intrusion will cause a “no start” or a “start and stall condition”..,don’t know how much you know about CAN buss but here is a great instructional video...watch it from the 1 hour mark !!
Last edited by C5 Diag; Nov 11, 2018 at 04:11 AM.
Race Director
Joined: Dec 2013
Posts: 12,505
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Normal for a OEM 05 radio to throw codes radio codes, when the BCM is set wrong and programming and it looking for a Nav radio not installediinstead.
Hence CD radio communicates fine on the scan, but since the BCM is programmed as having the Nav installed, when it goes looking for it, you get a U code for it when the BCM can not find it on the Gm lan bus.
Also, since some after market radio module are not allow to communicate back on the GM lan bus, then can cause a U code for the Radio as well. Hence they get/work with the wake up and sleep commands to work correctly, but since GM will not allow them to communicate back on the GM land bus (what is preventing the after market Nav radios from sending information to the Hud to display it there), not uncommon to get the U code for the after market radio module when the car goes looking for the stock radio isntead.
As for the after market radio causing the other problem codes, NO!!!!!
Hence CD radio communicates fine on the scan, but since the BCM is programmed as having the Nav installed, when it goes looking for it, you get a U code for it when the BCM can not find it on the Gm lan bus.
Also, since some after market radio module are not allow to communicate back on the GM lan bus, then can cause a U code for the Radio as well. Hence they get/work with the wake up and sleep commands to work correctly, but since GM will not allow them to communicate back on the GM land bus (what is preventing the after market Nav radios from sending information to the Hud to display it there), not uncommon to get the U code for the after market radio module when the car goes looking for the stock radio isntead.
As for the after market radio causing the other problem codes, NO!!!!!
