Check Engine Light

Check Engine Light

If you own a Toyota, Lexus or Scion you’ve seen the check engine light illuminate before you start the car. If the engine detects a malfunction with itself or auxiliary systems it will turn on this light solid, flash the light or (on a hybrid) set a Check Hybrid System warning on the display.  These all have unique meanings.  First, the solid check engine light and potential causes.

Solid, always on check engine light

A solid, illuminated check engine light indicates the vehicle has detected a malfunction in any of the various computer, sensing or monitoring systems that the engine has.  The light indicates the vehicle has stored a specific Diagnostic Trouble Code, of which there are 4 main types:

  • P-code: P code DTCs indicated a malfunction with the powertrain (the engine, transmission, or emissions systems).  P-codes can be caused by a failing gasket like in this post, or something more complicated and misleading like in this computer-related DTC.
  • B-code: B codes mean there is a malfunction detected with a body system.  These mostly pertain to modules that do things like adjust the climate control, radio, or power door.
  • U-code: U codes mean there is a malfunction with the on-vehicle network.  U codes are the most complicated to diagnose.
  • C-code: C codes mean there is a malfunction with the anti-lock brakes, traction control, or vehicle stability control system, like this ABS issue.

Flashing check engine light

A flashing check engine light indicates a normal code like above, but the the vehicle is also misfiring severely enough to damage your vehicle’s catalytic converter(s), oxygen sensor(s) and other exhaust related emissions components.  When the check engine light is flashing the car is usually shaking severely.  The vehicle will log misfire codes like in this Prius.  If you have a flashing check engine light, CARspec recommends you do not drive your vehicle to minimize the damage to your exhaust.  This will save you money in the long run.

Check Hybrid System

Check hybrid system

Check hybrid system

If your hybrid detects a malfunction with the engine, hybrid electric transaxle, inverter/converter or hybrid battery you’ll see this warning.  This indicator sets multi-level P codes – because of the complexity of the hybrid system’s electronics, the hybrid control module sets a general malfunction P code followed by a sub-code that narrows down the detected malfunction.  A hybrid battery failure can cause a Check Hybrid System message, as can inverter/converter failure.

If you have a check engine light, flashing check engine light, or Check Hybrid System malfunction CARspec is here to help.  Featuring state of the art factory diagnostic software and access to the entirety of Toyota and Lexus’s diagnostic library, the technicians at CARspec are ready to tackle even the most obscure malfunction.  As Eden Prairie and Chanhassen’s Toyota and Lexus independent service and repair shop we’re always happy to answer questions as well, so call us today at (952)426-4798!