《02Toyota Carryover-Evaporative Emission Control.ppt》由会员分享，可在线阅读，更多相关《02Toyota Carryover-Evaporative Emission Control.ppt（22页珍藏版）》请在三一文库上搜索。
1、,General The construction is changed to comply with the LEV-II evaporative emission regulations,Charcoal Canister,Canister Close Valve,Vapor Pressure Sensor,To Intake Manifold,Purge Valve,Tank Pressure Valve,Restrictor Passage,Air Filter,The construction is simpler than the conventional vacuum type,
2、Evaporative Emission Control System,Reference,General Conventional vacuum type,Charcoal Canister,Canister Close Valve,Vapor Pressure Sensor,To Intake Manifold,From Air Connector Pipe,Purge Valve,ORVR Valve,Pressure Switching Valve,Tank Pressure Valve,Air Inlet Valve,Air Drain Valve,Location,Charcoal
3、 Canister,Canister Close Valve,Vapor Pressure Sensor,Purge Valve,Tank Pressure Valve,Air Filter,Service Port,Evaporative Emission Control System,Charcoal Canister,Canister Closed Valve,Tank Pressure Valve,Charcoal Canister (3.0 liters),From Fuel Tank,To Fresh Air Line,To Intake Manifold,Evaporative
4、Emission Control System,Charcoal Canister The vapor guide prevents the vapor gas without passing through the activated charcoal,With vapor guide (03 Tundra),Without vapor guide (Conventional type),Include vapor gas*,To Intake Manifold,From Fuel Tank,To Intake Manifold,From Fuel Tank,Clean air,Absorb
5、 vapor gas,*: It will affect the air-fuel ratio control of the engine,Vapor Guide,Evaporative Emission Control System,Tank Pressure Valve Tank pressure valve controls the flow rate of the vapor gas from fuel tank to charcoal canister,When refueling (Tank pressure is large),Tank Pressure Valve,Vapor
6、Gas (From Fuel Tank),From Fuel Tank,Restrictor Passage,Evaporative Emission Control System,Evaporative Emission Control System,Tank Pressure Valve The restrictor passage prevents the large amount of vacuum that is created during system monitoring from entering the fuel tank,From Fuel Tank,Restrictor
7、 Passage,Restrictor Passage,If the large amount of vacuum enters the fuel tank during system monitoring, system monitoring is not performed normally,Air Filter The air filter prevents dust and debris in the fresh air from entering the system,To Fresh Air,To Charcoal Canister,The air filter is mainte
8、nance-free,Evaporative Emission Control System,Service Point,Air Filter If the air filter becomes clogged, the ECM illuminates the MIL and record the DTC P0446,DTC P0446 is detected (Canister Closed Valve close malfunction),Canister closed valve is OK,The air filter is clogging,System Operation Stor
9、ed fuel vapors are purged from the charcoal canister when the purge valve is opened by ECM,ECM,OPEN,OPEN,To Intake Manifold,Atmosphere,Duty,Stored fuel vapors,Evaporative Emission Control System,System Operation When refueling, the fuel vapors enter to the charcoal canister and they are cleaned,ECM,
10、Close,OPEN,OPEN,The internal pressure increases,The fuel vapors are Cleaned,Evaporative Emission Control System,System Monitoring When the initial conditions are met, the ECM introduces a vacuum into the system and monitors system to detect system malfunction,P1,Initial conditions are met,P2,P1,0 mm
11、Hg,Fuel Tank Pressure,Purge Valve,Canister Closed Valve,The ECM monitors the amount of pressure increase in the fuel tank,Open,Close,Open,Close,Value B,Value A,Evaporative Emission Control System,System Monitoring Step1,The ECM measures the amount of pressure increase (P1) in the fuel tank,Fuel Tank
12、 Pressure,Purge Valve,Canister Closed Valve,P1,0 mmHg,15 secs.,P1,Close,Close,Evaporative Emission Control System,System Monitoring Step2,The ECM opens the purge valve and introduces a vacuum into the fuel tank,Fuel Tank Pressure,Purge Valve,Canister Closed Valve,Open,Close,Evaporative Emission Cont
13、rol System,System Monitoring Step3,Fuel Tank Pressure,Purge Valve,Canister Closed Valve,Value B,Value A,Below value A,The ECM measures the amount of pressure increase (P2)in the fuel tank,P2,P2,5 secs.,Value B,Close,Close,Evaporative Emission Control System,System Monitoring System leak judgment,P2
14、Measurement,*: Reference value is stored in the ECM,Normal system control,Evaporative Emission Control System,P1 Measurement,The MIL illuminates and ECM stores the following DTCs in its memory,VSV Monitoring Normal condition,Purging,System monitoring,Purge Valve,System leak judgment,Canister Closed
15、Valve,Fuel Tank Pressure,Open,Close,Open,Close,Evaporative Emission Control System,VSV Monitoring Purge valve open malfunction,DTC P0441 is memorized, The MIL illuminates,When the ECM is measuring the P1 value, the pressure in the fuel tank drops rapidly,It remains in a constant, slight vacuum state
16、,Malfunction Judgment,Purge Valve,Canister Closed Valve,Fuel Tank Pressure,Normal Condition,Open,Engine Starting,Evaporative Emission Control System,VSV Monitoring Purge valve close malfunction,DTC P0441, P0442 and P0446 is memorized, The MIL illuminates,Purge Valve,Canister Closed Valve,Fuel Tank P
17、ressure,Close,Malfunction Judgment,The pressure does not change,No vacuum is introduced,Evaporative Emission Control System,VSV Monitoring Canister closed valve open malfunction,Purge Valve,Canister Closed Valve,Fuel Tank Pressure,Open,DTC P0441, P0442 and P0446 is memorized, The MIL illuminates,Mal
18、function Judgment,A slight vacuum is created,It is not possible to completely introduce a vacuum,Evaporative Emission Control System,VSV Monitoring Canister closed valve close malfunction,Purge Valve,Canister Closed Valve,Fuel Tank Pressure,DTC P0446 is memorized, The MIL illuminates,Malfunction Judgment,A large amount of vacuum is introduced,Close,Evaporative Emission Control System,