HE72 - Run KOER Self-Test While Monitoring EGR Vacuum

- Key Off.

- Disconnect vacuum hose at EGR valve and connect hose to a vacuum gauge.

- Run Key On Engine Running (KOER) Self-Test while monitoring gauge. Approximately 30 seconds into test, EGR flow will be requested for a few seconds. The vacuum at this time should increase above 1.6 inHg to open the valve.

NOTE: Since the EGR vacuum hose is disconnected, ignore DTCs during this KOER Self-Test.

- Does the vacuum increase to 1.6 inHg or greater at any time during KOER Self-Test?

YES -- The vacuum indicated is sufficient to open the EGR valve. Fault is unlikely to be in EGR vacuum control. GO to HE73. HE73 - Inspect DPFE Sensor Pressure Hoses

NO -- The vacuum indicated is insufficient to open the EGR valve. GO to HE80. HE80 - Check Vacuum Source and Hoses to and From EVR Solenoid