Operation CHARM: Car repair manuals for everyone.
Home >> GMC >> 1999 >> Safari Van AWD V6-4.3L VIN W >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Scan Tool Testing and Procedures >> Scan Tool Data, Normal Values and Definitions >> Scan Tool Data Definitions - Powertrain Systems >> EGR Duty Cycle
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 Duty Cycle

Range 0 - 100%.
The EGR Duty Cycle determines the percentage of time the EGR valve's control circuit has 12 volts applied to it. This is a method to control the current applied to the valve motor. As duty cycle increases, so does current which forces the valve to open further and allow more exhaust gas to enter the intake. 100% duty cycle would indicate a fully opened valve.
pro multis · About Operation CHARM