Operation CHARM: Car repair manuals for everyone.

Clearing Diagnostic Trouble Codes


1. Turn ignition switch to OFF position.
2. Deactivate STAR tester by depressing self-test button. The colon should disappear from the display window.
3. Turn ignition switch to ON position.
4. Activate STAR tester by depressing self-test button. As soon as the tester begins to display service codes (even code 11), deactivate self-test sequence by depressing the self-test button.
5. The colon as well as any service code displayed should disappear from the tester window. Any memory codes held in storage will be erased at this time.
6. Ensure that the memory codes have been erased by turning ignition switch to OFF position and repeating steps 3 and 4. Do not erase intermittent faults from the ECA memory until they have been corrected.




Continuous Memory
1. Perform Key On Engine Off self-test.
2. When service codes begin to be displayed, deactivate self-test as follows:
a. STAR tester, position center button in up position.
b. Analog Volt/Ohmmeter, remove jumper wire from self-test input connector and signal return pin of the self-test connector.
c. Check engine light, remove jumper wire from self-test input connector and signal return pin of the self-test connector.
d. Message center, remove jumper wire from self-test input connector and signal return pin of the self-test connector.
3. Continuous codes should now be erased.

Keep Alive Memory (KAM)
To clear keep alive memory, disconnect negative battery cable for a minimum of five minutes. After clearing memory, it is necessary to vehicle a minimum of 10 miles to allow processor time to relearn value.