Canada

EGR & Canister Control:

PURPOSE
The EGR System controls the formation of NOx (Oxides of Nitrogen) emissions by recirculating some of the exhaust gases into the combustion chamber. The exhaust gas in the combustion chamber lowers the peak ignition temperature.

OPERATION
A system is provided which precisely cuts and controls port vacuum applied to the EGR valve and canister to suit engine operating conditions. This cut-and-control operation is accomplished through the ECM. When the ECM detects any of the following conditions, current flows through the solenoid valve in the EGR and canister control vacuum line.
This causes the port vacuum to be discharged into the atmosphere so that the EGR valve and canister remain closed.
1) Low engine coolant temperature
2) Engine starting
3) High-speed engine operation
4) Engine idling
5) Excessively high engine coolant temperature
6) Mass air flow sensor malfunction