By model
The codes and fixes that show up most on each Toyota.
Toyota Camry
A stored engine fault. Complaints cluster on 2018–2020 cars and oil-burning 2007–2009 cars
Toyota Corolla
A stored engine fault. On 2005–2008 Corollas, rule out ECM recall 10V-384 before anything else
Toyota Corolla
Traction control (TRAC) is off. If the switch wasn't pressed, the 2014 Corolla manual says TRAC can't operate: contact a Toyota dealer
Toyota Highlander
A stored fault. 2017–2018: Toyota's transmission program ZJC lists it. 2006–2010 Hybrid: inverter recalls
Toyota Prius
The Prius logged an engine OR hybrid-system fault — gen-3 EGR/misfire issues are well-known
Toyota RAV4
A stored engine fault. 2001–2003: Toyota tied shift codes to the ECM. 2019–2021: ask about program 24TE04
Toyota RAV4
Traction control is off or can't operate. On 2006–2012 RAV4s, owners often report it with the check engine and 4WD lights; Toyota doesn't say why
Toyota Sienna
A stored fault code, often with VSC and TRAC OFF. On certain 2017–2018 vans, a ZJC transmission symptom
Toyota Tacoma
The Tacoma's engine computer logged a fault — EVAP and O2 sensors lead, plus misfires
Toyota Tacoma
TRAC OFF lit without the switch means TRAC can't operate (2012, 2015 and 2018 manuals). On 2012 trucks, owners mostly trace it to secondary air injection
Toyota Tundra
The Tundra's computer logged a fault — on the 5.7L V8, secondary air injection (AIR) is a known one