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

Operation With System Failures


In the event the ECM detects a system malfunction, the light will be activated, the corresponding trouble code stored and substitute values to replace missing data may be made available for computations by the ECM. This can be thought of as a ``Fail Safe'' operation. In this mode, driveability of the car may be poor under certain condition and the diagnostic procedures should be exercised.