History Codes

History codes are those indicating that the CCM previously detected a fault which later disappeared. The reason could be either that the fault is a true intermittent, only happening occasionally, or that the system for which the code is set is not currently being operated. An example of this would be the Rear Defogger system; it does not operate unless the engine is running. Since a technician would most likely be using CCM Diagnostics with the engine "OFF," a rear defogger code would always show as history, though the fault was currently present. For this reason, if a code is displayed as a history code and the fault cannot be found easily, try clearing the codes and operating the system that the code applies to. If the code resets, it can be assumed that the condition is present.