Trouble Code Memory
DescriptionWhen a fault develops in the system, the test light will come on and a trouble code will be set in the memory of the ECM. However, if the fault is intermittent the test light will go out when the fault goes away, and the trouble code will remain in the memory of the ECM.
Long Term Memory
The ECM in this system has long term memory, so trouble codes are not lost when the ignition is turned OFF. Some trouble codes may not be displayed until the system has been operated 5 to 18 minutes at part throttle. For this reason and to diagnose intermittent problems, this long term memory feature is more desirable. To clear long term memory, disconnect the negative battery cable for a few seconds.