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

EGR Control Solenoid: Description and Operation



EGR Duty Solenoid And Vacuum Switching Valve:





EGR system control and optimum EGR volume are determined by the ECM based on three main signals:

1. Engine RPM
2. Intake air volume
3. Coolant temperature

To operate the system, the ECM controls a duty solenoid which in turn regulates vacuum to the EGR valve. Also incorporated into the system is an ECM controlled vacuum switching valve for EGR cut under specified conditions.