Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Hello,
I recently started my own mobile service business. And I have been getting a few customers. The ones I get are either super easy or way out of my realm. I've got 5 vehicles with lost communication codes, U-codes, B-codes. I am not strong in the graphing and scoping world don't even know what tool to get that would do that and be worth it. I'm asking what are u codes and B codes? Where are the best schematics found or wiring diagram or information on vehicles modules locations?
I just paid for the premium, and I'm hoping I learn how to diagnose cars more accurately and repair them the first time.
P codes, like p0300 etc are Powertrain codes.
B codes refer to non Powertrain or body control systems
U codes indicate a network or communication fault. It is generally accepted the the module that sets the U code is not at fault, it is warning that another module on its network has an issue.
It is not uncommon during a system code scan for multiple modules to have some U or B codes set when there is no issue present. It is important to not get lost in the weeds you see these codes and remember why you are looking at the car in the first place. If the symptoms you are troubleshooting are not related to the codes set in various modules, then you don't necessarily need to try and figure out why these codes are set in various modules. It is important to know what not to fix.
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