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

The EGR vacuum switching valve (VSV) is normally closed to prevent the EGR valve from opening when the engine is started cold and blocks the vacuum signal to protect the EGR valve diaphragm from excess turbocharger pressure. The ECM will energize the VSV and allow EGR valve operation only when preprogrammed values from these devices are met:

Coolant temperature sensor
MAP sensor
Throttle position sensor
Engine rpm