The damage indicator light ( MIL ), or check the machine lights , is a fairy tale used by the computerized-machine management system to show malfunctions. Found in the instrument panel of most cars, usually containing a spangle checking machine , service machine soon , or machine pictogram - and when illuminated it is usually yellow or red.
Light generally has two stages: stable (indicates a small error) and blinks (indicates a severe error). When MIL is turned on, the machine control unit stores error codes associated with malfunctions, which can be retrieved - although in many of these models requires the use of a scan tool. This warning light can show almost anything from a loose gas cap to a serious tap on the machine.
In the United States, special functions are required for MIL by EPA regulations.
Video Check engine light
Histori
Some older vehicles have a single indicator labeled "problem" or "machine"; this is not a MIL, but an "idiot lamp" is meant to indicate a serious problem with the engine (low oil pressure, overheating, or charging system problems) and impending trouble. The use of "engine" lights was discontinued in the mid-1980s, to prevent confusion with MIL.
MIL appeared in the early 80s along with computer engine controls. Even the earliest systems, such as the GM's CCC (Control Computer Command) system have a self-diagnostic function. When the computer detects an error, it illuminates the MIL. Until OBDII, in most cars MIL can issue code, when two pins on ALDL are skipped, the light will flash code, for example blink for code 12. Some manufacturers, like Honda, this is even after OBDII.
MIL is often referred to today as a "check engine light" or "service engine immediately lit".
Maps Check engine light
Odometer trigger
Some vehicles manufactured from the late 1990s through the mid-2000s have MILs that light up based on odometer readings, regardless of machine operation. For example, in some Mazda models, light will come at 80,000 miles (130,000 km) and stay on without generating computer code problems. Volvo has a light labeled "Lambda", Lambda Sond becomes another name for oxygen sensors. This is done to remind the driver to change the oxygen sensor.
Some American Chrysler Corporation vehicles from 1973 to 1976 had a similar odometer-triggered reminder: "Check EGR", which was reset after service at Chrysler dealership. MIL also lights up before starting the engine, along with other stories on the dashboard, to show that the lights are working and not burning. The light will die after the car starts up if no errors are observed. MIL will also turn on if the machine has been turned on but fails to start after returning the ignition key to "ON." In most modern vehicles this is usually because it does not provide enough time to start the engine. In the pre-fuel injection years, many crank businesses are sometimes required to start the car. If the machine fails to start at the second or third attempt, then a real visual inspection of the machine may be required. If the engine suddenly stops or is triggered by an excessive load, such as in a manual transmission car, MIL will also turn on until the engine turns on again.
Incorrect trigger
Higher amounts of methanol/ethanol (or other additives) from machines equipped for handling can trigger MIL (see E85). This burns differently from gasoline, and the EFI system may mistakenly interpret the oxygen sensor readings as incorrect. Oxygen gas can cause the wrong trigger in the early EFI system.
See also
- OBD-II PIDs ("Parameter ID")
References
Source of the article : Wikipedia
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