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Reading B and U codes

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Old Sep 21, 2014 | 12:07 AM
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GCRoberts's Avatar
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Default Reading B and U codes

My Corvette is currently throwing B and U codes. I know this because I saw them come up when I took my car in to diagnose a "Service Electrical System" message on my dashboard. The dealer wouldn't cover under warranty because I have an aftermarket radio. Other than the VERY EXPENSIVE GM Tech 2 scanner, does anyone know of a way to read these codes? I want to do some of my own investigation into this issue.
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Old Sep 21, 2014 | 08:29 PM
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Your U codes may be caused be the aftermarket radio you installed. Stock radio units are hooked to the car's communication network, since U codes are caused by loss of communication between the different modules in the network, if you can't read the code with a cheap code reader you may not be able to turn the code off.

You don't give information about the car. Some ELM327 cables with a good software can access other modules in the car other than the PCM. Depending on the year, the different modules talk to each other using another communication bus and only high end scanners can access that bus.
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