How do I look up a fault code?

Open DTC search in the portal and type either the code itself (for example P0299) or a keyword describing the fault. DTC stands for diagnostic trouble code — the codes a diagnostic tool reads out of a vehicle.

What can I search for?

• The code. Type it with or without the letter prefix; both find the same entry.
• A keyword. "turbo underboost", "glow plug", "lambda" — the search matches the description text, which is useful when you have the symptom but the code is not in front of you.

You can narrow the results by category when a code prefix is ambiguous across systems.

Why look a code up before ordering?

Because a code changes what you order. Some faults are a mechanical problem the tune cannot fix, and some are exactly what a DTC-off service is for. Naming the fault in the order's notes also saves a round trip — the supplier can see what you are trying to solve rather than guessing from the file.

Does a code in this list mean it can be switched off?

No. The list is a reference for identifying a fault, not a statement about what your supplier will do with it. Whether a specific code can be removed depends on the vehicle, the ECU and your supplier's own policy — ask on the order.

The code I have is not in the list

Manufacturer-specific codes vary between brands, and the list cannot hold every variant of every marque. If a code does not resolve, search the description instead, and put the raw code in the order notes so the supplier sees exactly what the tool reported.