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

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EGR Control Solenoid: Description and Operation


On cold engine start-up the ECM receives input from the MAT sensor (Manifold Air Temperature), and if the MAT reading is less than 12~C (57~F) the EGR solenoid is off until the coolant warms to 80~C (176~F). If there is a malfunction of the MAT sensor then the ECM receives input from the coolant sensor.