Trouble Code Memory

Description


When 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, but the trouble code will remain in the memory of the ECM.

Long Term Memory

The ECM in this system has a long term memory, so that trouble codes are not lost when the ignition key is turned off. Also 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. If it is necessary to clear this long term memory, disconnect and connect the negative battery ground cable.