Diagnostics, explained
How to read fault codes, work through a diagnosis and get more out of your scanner. Written for mechanics.
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How to read a BYD fault code
What the letters and digits in a DTC actually mean, and what a code can — and cannot — tell you before you start work.
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Why network codes are so common on electric vehicles
A U code usually means a module went quiet, not that it failed. Here is what actually causes them, and how to tell the difference before you order a part.
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What “implausible signal” really means
The controller is telling you it does not believe a number. That is a different problem from a broken sensor, and it is chased in a different order.
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Reading freeze frame data
The conditions recorded at the instant a code set will often name the fault faster than the code itself — and clearing the code destroys them.
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Check the grounds before you replace a control module
A bad ground imitates almost any module fault, costs nothing to test, and is the cheapest place in the whole job to be wrong.