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

Electronic Engine Controls



The engine management system consists of a powertrain control module and a number of sensors and actuators. The sensors supply the powertrain control module with input signals which relate to engine operating conditions and the actuators respond to output signals from the powertrain control module. These output signals are based on the evaluated input signals which are compared with calibrated data tables or maps before the output signal is generated.