Fuel Injection System - Diesel: Testing: EGR

Proper EGR solenoid resistance is between 20-40 ohms. The solenoid operates on 12 volts, supplied by the ignition. The ground is completed by the ECM (Electronic Control Module) to turn the solenoid "ON", allowing vacuum to the EGR. The signal from the ECM is Pulse Width Modulated, which changes "ON" time from 0 to 100%.