Theory Of Operation

WARNING: This page is about a different variant/trim than selected.

The High Pressure Exhaust Gas Recirculation (HP EGR) Cooling Bypass system is used to redirect the HP EGR gases around the HP EGR Cooler when the engine is under certain operating conditions. The system consists of two devices.

The HP EGR Cooling Bypass Solenoid is a 2-wire electrical device. The solenoid is located on the Intake Manifold. This solenoid controls the crankcase vacuum supply to the HP EGR Cooling Bypass Actuator.

The EGR Cooling Bypass Actuator is a typical 'vacuum-diaphragm' device. The actuator is located on the EGR Cooler and is activated when the engine is cold or at idle.

The Powertrain Control Module (PCM) will light a MIL lamp after this monitor runs and fails in two consecutive drive cycles. The PCM will turn off the MIL lamp after the diagnostic passes in four consecutive drive cycles.