Powertrain fault codes

How to read a code

P

SystemPowertrain

0

Defined bySAE, the same on every car

4

AreaAuxiliary emission controls

20

FaultThe specific fault in that area

1. 1

   Read the code

   Note every stored and pending code your scanner shows, such as P0420.

2. 2

   Find it

   Search by code or by words. For a manufacturer code (P1, B1, C1, U1) pick your make: its meaning differs by make.

3. 3

   Open the code

   Its page explains the symptoms, likely causes, the checks to run and the fixes.