ASCNG_25.PDF

EMISSION CONTROL SYSTEM

GENERAL INFORMATION

The emission control systems used on both the

compressed natural gas (CNG) and gasoline powered

vans equipped with the 3.3L V-6 engine are the

same. This is except for the deletion of certain com-

ponents on the CNG vehicle. They are:

The EVAP canister

from the fuel tank and venting into the atmosphere.

Because the engine is not using gasoline, and the

CNG cylinders are sealed to the atmosphere, EVAP

canister and canister purge solenoid are not used

with the CNG system.

For all other emission control system diagnosis,

testing and component removal or installation, refer

to the 1994 Town & Country, Caravan, and Voyager

service manual (number 81-370-4105). See Group 25,

Emission Control System.

The EVAP canister purge solenoid (duty cycle)

The EGR valve and connecting tube

The EGR valve vacuum/electric solenoid (EET)

The function of the EVAP control system is to pre-

vent the emissions of gasoline vapors from escaping