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

On Board Diagnostic Tests

A diagnostic test is a series of steps which has a beginning and an end. The result of which is a pass or fail reported to the Diagnostic Executive. When a diagnostic test reports a pass result, the Diagnostic Executive records the following data:
^ The diagnostic test has completed since the last ignition cycle
^ The diagnostic test has passed during the current ignition cycle
^ The fault identified by the diagnostic test is not currently active

When a diagnostic test reports a fail result, the Diagnostic Executive records the following data:
^ The diagnostic test has completed since the last ignition
^ The fault identified by the diagnostic test is currently active
^ The fault has been active during this ignition cycle
^ The operating conditions at the time of the failure