EVAP System - MIL ON/Codes 171/173/179 Set: Overview

9210ford01

Article No.
92-3-7

01/29/92


^ EVAPORATIVE EMISSION SYSTEM - 5.8L - MALFUNCTION INDICATOR LIGHT ON - EXCESSIVE CANISTER PURGE FLOW - 0/8500 GVW

^ LAMP - MALFUNCTION INDICATOR LIGHT (MIL) ON EXCESSIVE CANISTER PURGE FLOW - 0/8500 GVW


LIGHT TRUCK: 1991 E-250, E-350, F-250, F-350


CALIBRATION: 1-76B-R00, 1-75A-R00, 1-76A-R00, 1-76C-R00

WARNING: THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.

ISSUE: The Malfunction Indicator Light (MIL) may be ON indicating service codes 171, 173 and/or 179. This occurs because of excessive canister flow through the mechanical ports of the throttle body at temperatures greater than 100 degrees F (38 degrees C), or at altitudes greater than 5000 ft. (1525 meters).

ACTION: Perform the necessary engine/emissions diagnosis and, if required, install a new vapor canister assembly and in-line purge hose restrictor. Refer to the following procedure for service details.