Caprice V6-262 4.3L (1987)
Canister Purge Control Valve: Testing and Inspection
Component Diagnostic Charts - Throttle Body Fuel Injection
Fig. 101 - Wiring Diagram for Chart C-3 Canister Purge Valve. VIN Z
CHART C-3
CANISTER PURGE VALVE CHECK
4.3L "B/G" SERIES
FUEL INJECTION (TBI)
Circuit Description:
Canister purge is controlled by a solenoid that allows manifold vacuum to purge the canister when de-energized. The ECM supplies a ground to
energize the solenoid (purge "OFF").
If the diagnostic test terminal is grounded with the engine stopped or the following is met with engine running the purge solenoid is de-energized
(purge "ON").
a. Engine run time after start more than 1 min.
b. Coolant temperature above 80°C
c. Vehicle speed above 5 mph.
d. Throttle off idle. TPS signal about .75 volt.
