Mitsubishi Eclipse II technical information manual page 54

text version of content this owner's manual page from owners manual to the vehicle Mitsubishi Eclipse, year of production 1995 - 1999:

ENGINE - Control System 1-33 DTC Identification, Maturation, and Erasure N7lAKMAA Once a test has been run, the diagnostic system DTC’s are erased if the component passes the diag- iidetermines whether the system has passed or failed. nostic test in the course of a number of subsequent It must then determine if the test has failed the warm-up cycles. The number of trips required for specified number of times required to illuminate the this is usually 40. This is why it is best to attempt MIL. If not, the diagnostic system stores a maturing to diagnose intermittent problems soon after they code. When this test is run again (on the next “trip”) occur. While initially a DTC may have been available, the results are once again either pass or fail. If subsequent trips (which passed the diagnostic test) the component fails the test, a code “matures,” and have erased the code. The OBD II system, based a DTC is set. The MIL lamp is illuminated if an on the latest inputs it received, reconsidered its emission component is involved. If the component diagnosis on this intermittent concern. or system passes the test a specified number of times, the maturing code is erased. Of course, a diagnostic scan tool can be used to NOTE erase DTC’s at any time. In addition, DTC’s (along with records of successful trips) are erased whenev- It is important to understand that a system need er the vehicle’s battery is disconnected. not fail a test under exactly the same conditions for a code to nature and trigger the MIL. Freeze Frame Data Storage and Erasure N7lAK35AA Information in the freeze frame includes: All monitored systems provide “freeze frame” data of the vehicle’s operating conditions when a matur- l Diagnostic Trouble Code (DTC) ing code was set. This information can be retrieved l Engine rpm using the diagnostic scan tool and may help a techni- l Engine load cal pinpoint the source of a concern more quickly. l Fuel trim (short term and long term) When there are multiple monitor failures, the first to occur is stored in freeze frame. The exceptions o Engine coolant temperature are the misfire and fuel system monitors. They have l Manifold absolute pressure l Operation mode (open or closed loop) priority and can write over other freeze frame data. L l Vehicle speed Freeze Frame Priority N71AK3SAA The freeze frame only indicates the operating condi-the vehicle must repeat successfully during a test to allow the diagnostic system to erase a DTC and tions under which the maturing code was set. While turn off the MIL on its own. these conditions are usually the same as those which trigger the maturation of the DTC, there can Should the diagnostic system determine that the be exceptions. This first condition is important for DTC can be erased, the freeze frame related to fuel system and misfire DTC’s as it is the condition that code is also eliminated. MIL Illumination N7l AK37AA a larger number of warm-up cycles (40) have been As described earlier, the PCM diagnostic system successfully completed. is responsible for operation of the MIL lamp. This is an important function as unnecessary operation The MIL flashed in misfire situations where contin- of this lamp has a negative effect on customer satis- ued driving could damage the catalytic converter. faction. In most cases, if a component or system Continued driving of the vehicle when this condition passes diagnostics on three consecutive trips after occurs is not recommended. the MIL has been illuminated, the MIL is extin- The MIL can be used to produce diagnostic trouble guished. This explains how customers can note that the “Check Engine” light went on, and then codes. Quickly turning the key to the RUN position three times allows the MIL to flash out any existing off, on its own. The OBD II has reconsidered its flash codes. diagnosis. The DTC remains in the memory until

owners manual Mitsubishi Eclipse

owners manual Mitsubishi Eclipse - year of production: 1995, 1996, 1997, 1998, 1999 - Mitsubishi Eclipse II technical information manual EN