Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Trouble Code Memory


The ECM is capable of sensing certain system malfunctions, storing data related to these malfunctions in the trouble code memory and alerting the operator of the malfunctions through the instrument panel mounted "Check Engine" lamp. If a system malfunction occurs while the engine is running, the ``Check Engine'' lamp will light and a trouble code will be stored in the ECM memory. The lamp will remain on with the engine running until malfunction is corrected. If the malfunction is intermittent, the lamp will go out but the code will remain stored in the trouble code memory.