Page 257 - Foton Workshop Manual - Aumark (BJ1099)

ENGINE CONTROL SYSTEM - CANISTER PURGE CONTROL VALVE 11-31
CANISTER PURGE CONTROL VALVE

1. Principle of work
Canister purge control valve has a solenoid valve system inside and its jaw opening
is controlled by the digitalized pulse square wave output by ECM. With different
operating conditions of the engine, the jaw opening of canister purge control valve
changes. If the load of the engine is huge enough to idle, the canister purge control
valve will not operate in order to protect the output power of the engine.
2. Function and installation 11
The function of the canister purge control valve is to control and adjust the fuel
vapor volume, which is absorbed by activated charcoals in the canister and then
flows into the admission manifold, with ECU electronic control unit. Canister purge
control valve is fixed in its sheath.
3. Fault phenomenon and judgment method
(a). Fault phenomenon: function failure, etc..
(b). General causes for faults:
The rustiness and poor sealing performance caused by foreign matters entering into
the valve, etc..
(c). Precautions for maintenance:
• The direction of air flow must be in conformity with regulations in the process of
installation.
• Please check the condition of the canister, if the control valve should be replaced
for finding that the control valve fails because of the black granules.
• Try to avoid getting liquid such as water, oil, etc. into the valve in the process of
maintenance.
• Canister purge control valve must be installed with the canister purge control
valve bush in order to avoid the transmission of the solid-borne noise.

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