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
Passive and Active Diagnostic Tests
A passive test is a diagnostic test which simply monitors a vehicle system or a vehicle component. An active test actually takes some sort of action when the performing diagnostic functions. An active test is often in response to a failed passive test. For example, the
exhaust gas recirculation (EGR) diagnostic active test may force the
EGR valve open during a closed throttle deceleration maneuver. Or the EGR diagnostic active test may force the EGR valve closed during a period of steady speed driving. Either action should result in a change in the manifold pressure.