How-to
How to read OBD2 codes (beginner)
OBD2 ports sit under most dashboards since the mid-1990s. A basic DeepScan reader shows diagnostic trouble codes (DTCs). Codes point to a system — they are not always a parts list.
Independent MyGooloo guide — authentic GOOLOO products, purchases on Amazon. Affiliate disclosure.
Beginner workflow
- Ignition on (engine may be off — follow your scanner prompt)
- Plug into the 16-pin OBD2 port
- Read and photograph stored / pending codes
- Look up the code + your vehicle before buying parts
- Fix the cause, then clear codes and confirm they stay gone
Code letter basics
P-codes relate to powertrain (engine/transmission). B/C/U codes involve body, chassis, or network — many entry readers focus on powertrain. Step up DeepScan models if you need broader modules.
Recommended next steps
- DS100 Start here for CEL
- Which scanner for CEL? DS100 vs step-ups
