Symptoms

Warning lights and what they mean — TRAC OFF, flashing light, and per-model causes.

An active engine misfire — raw fuel is reaching the exhaust

The Camry's engine computer logged a fault — usually EVAP, an O2/air-fuel sensor, or a misfire

The engine computer stored a fault from the emissions, fuel, ignition, or sensor systems

The Corolla's engine computer logged a fault — often the same one that lights TRAC OFF

The Highlander's computer logged a fault — often the same one that lights VSC / TRAC OFF

The Prius logged an engine OR hybrid-system fault — gen-3 EGR/misfire issues are well-known

The RAV4's engine computer logged a fault — usually EVAP, an O2/air-fuel sensor, or a misfire

The Sienna's engine computer logged a fault — EVAP and O2 sensors lead on the V6 minivan

The Tacoma's engine computer logged a fault — EVAP and O2 sensors lead, plus misfires

The TRAC OFF light stays on after a button press or a repair — traction/stability control is still switched off

The Tundra's computer logged a fault — on the 5.7L V8, secondary air injection (AIR) is a known one

An engine fault made the Corolla's computer switch traction (TRAC) and stability (VSC) control off

An engine fault made the RAV4's computer switch traction (TRAC) and stability (VSC) control off as a fail-safe

An engine fault made the Tacoma's computer switch traction (TRAC) and stability (VSC) control off as a fail-safe

An engine fault made the computer switch traction (TRAC) and stability (VSC) control off as a fail-safe

Both traction (TRAC) and stability (VSC) control are switched off — by the dashboard button, or by a stored fault