Powertrain Diagnostic Trouble Code Guides
Free step-by-step guides to diagnose Powertrain OBD-II trouble codes. Choose your subsystem below.
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All Powertrain DTC Codes
Emissions medium
P0402
The engine control module (ECM) has detected that more exhaust gas is being recirculated than the sy...
Emissions medium
P0411
The engine control module (ECM) has detected that the secondary‑air injection (SAI) system is delive...
Emissions medium
P0420
The P0420 code means your catalytic converter is not cleaning exhaust gases as efficiently as it sho...
Emissions medium
P0451
The engine control module has detected that the EVAP‑system pressure sensor is reporting values outs...