System Readiness Test (SRT) Code

SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Mode 1 of SAE J1979. It indicates whether the self diagnostic tests for non-continuously monitored items have been completed or not.
Inspection/Maintenance (I/M) tests of the on board diagnostic (OBD) II system may become the legal requirements in some states/areas. All SRT codes must be set in this case. Unless all SRT codes are set, conducting the I/M test may not be allowed.
SRT codes are set after self-diagnosis has been performed one or more times. This occurs regardless of whether the diagnosis is in "OK" or "NG" and whether or not the diagnosis is performed in consecutive trips. The following table lists the five SRT items (18 test items) for the ECCS used in L30 models.

Together with the DTC, the SRT code is cleared from the ECM memory using the method described later. In addition, after ECCS components/system are repaired or if the battery terminals remain disconnected for more than 24 hours, all SRT codes may be cleared from the ECM memory.