Continuous Memory Self-Test

NOTE: Continuous memory self-test may also be known as memory test.

Continuous memory self-test is a functional test of PCM performed under any condition (engine running or engine off) with ignition switch turned to ON position. Unlike KOEO and KOER self-tests which can only be activated on demand, continuous memory is always active in monitoring the system. When a fault is detected, DTC will be stored in memory. This makes it possible to diagnose intermittent faults. Memory codes should be serviced last, after all other DTCs.

There are 2 types of continuous memory DTCs. Emission related DTCs will illuminate the Malfunction Indicator Light (MIL) on instrument cluster. Non-emission DTCs will never illuminate MIL. On emission-related MIL DTCs, PCM will store DTC in continuous memory at first detection of problem. The MIL will not be illuminated, but DTC is considered by PCM to be a pending DTC. If same problem is detected in next drive cycle, MIL will illuminate. MIL will go out if fault is not present after 3 consecutive drive cycles, or PCM has been reset. An emission-related pending DTC or non-emission DTC will be erased after 40-80 warm-up cycles or PCM reset.