109 

 

No.061 Quick diagnosis for canister solenoid valve   

 

Function: for controlling flow of regenerated air flow of fuel evaporation control system.   
Principle: canister of fuel evaporation control system could absorb oil vapor of oil tank, till 
saturation. After canister control valve by electronic controller is opened, fresh air and fuel vapor 
saturated in the canister will form regenerated air flow, and reintroduce to engine inlet pipe. And 
electronic controller will change duty ratio of impulse signal transferred to magnet coil of canister 
control valve according to engine’s different conditions, thus controlling over flow of regenerated 
air flow. In addition, this flow is affected by pressure difference at two s ides.   

 

 

 

Definitino of TEV pin:   
1#  TEV driver stage pin; 
2#5#  TEV control pin;  
Maintenance precautions: 
1. When installing, airflow direction shall conform to specifications; 2. In case control valve 
becomes invalid due to black particle within valve body, and needed to be replaced, check 
canister; 3. During maintenance, avoid liquid such as water, oil from entering to valve; 4. To 
avoid transfer of solid borne noise, recommend to hang up canister control valve and install it at 
hose.  
Simple measuring method: 
1. (remove the connector) place digital multimeter to ohm position, and two pens are respectively 
connected to two pins of canister control valve; rated resistance is 26Ω under 20 ; 

℃

 

2. Remove canister control valve, and absorb the air inside and check; canister control valve 
shall be stuffy; then apply battery voltage of 12V to two connecting terminals, and absorb the air 
to control valve, and the valve shall be airing. If upon check, status of canister control valve is not 
consistent with above check results, it indicates that it is malfunction, and replace it;   

 
 

 

 

110 

Diagnosis flowchart for canister control valve

 

 

1. Ignition switch closed: remove joint of canister control valve, and turn on 

ignition switch, but unable to start the engine. Measure there is 12V voltage 

to ground at one terminal of socket connector?   

2. Check lines between main relay terminal 87 and canister control valve are 

open circuited, shorted to ground or to power source?   

3. Check resistance of canister control valve is 5-50Ω? 

4. Ignition switch closed: remove ECU joint: check lines between ECU and 

canister control valve are open circuited, shorted to ground or to power 

source?

5. Replace canister control valve   

6. Replace ECU, and confirm repairs are completed.   

Repairs 

Repairs  

Y 

Y 

Y 

Y 

N 

N 

N 

N 

Y 

 
 

 

 

111 

No.062 Fuel injector EV   

 
 

 

•    Function: fuel injector ejects fuel within specified time according to instructions of ECU, and 
provides fuel to the engine and make it atomized.   
 
•    Principle: ECU supplies power to coil of fuel injector, forming magnetic field force; when this 
force increases enough to overcome resultant of pressure of release spring, gravity of needle 
valve and friction force, needle valve starts to rise, and fuel injection starts. When injection 
impulse stops, pressure of release spring will make needle valve re-closed.   
•    Mounting position: Intake manifold close to inlet valve.   
 
Malfunction:    Poor idling speed, poor acceleration, unable to startup (difficult startup), etc.   
General causes: Colloid deposit within fuel injector due to lack of maintenance, causing it 
ineffective.  
Maintenance precautions: 1. There are many types of fuel injectors, and those with the same 
appearance and which could be installed may not be the proper one. Part number for injector 
during repairs must be the same with that of original injector. Do not mix up; 2. To ensure 
convenient installation, apply clean silicon-free oil at surface of upper O ring connected with fuel 
distribution pipe. Do not pollute inner of oil injector and jet orifice; 3. When removing and 
reassembling fuel injector, replace O ring; do not damage sealing surface of fuel injector; 4. If 
fuel injector has two slots, make it correct when installing clamps by referencing mounting 
position of original parts; 5. Do not remove, and clean or replace filter screen without permission; 
6. After removing, make sure fuel injector seat is clean. Avoid foreign substances entering to the 
cylinder. 

1. O 

ring 

2. Filter 

screen 

3.  Ejector body with electric 

plug 

4. Coil 

5. Spring 

6.  Valve needle with coil 

 
 

 

 

112 

Simple measuring method:   
(remove the connector) Place digital multimeter to ohm position, and two pens are respectively 
connected to two pins of oil injector, and rated resistance is 11-17Ω under 20 . 

℃

 

Suggestions: thoroughly clean oil injector with special cleaning analyzer for each 20000kM.   
Diagnosis flowchart for oil injector 

 

1. Close ignition switch and disconnect joint of oil ejector; connect voltmeter 
to No. 1 terminal of the first cylinder ejector and earth between; switch on 
ignition switch, and observe voltage of No. 1 terminal of oil ejector is 12V 
instantaneously? For other oil ejectors, same steps.   

2. Repair earthing, short circuit and open circuit between main relay, oil 

pump relay, oil ejector 

3. Check lines between oil ejector and ECU terminal (17-2) are open 
circuited, shorted to ground or to power source?   

4. Close ignition switch, and remove joint of oil ejector: measure resistance 
of each oil ejector is lower than 15.95Ω one by one with ohmmeter? 

5. Connect oil ejector joint of each cylinder and ground with ohmmeter; 
measure resistance between each oil ejector and ground is larger than 
1MΩ?  

6. Replace oil ejector 

7. Replace ECU   

Completed  

Repairs  

Y 

Y 

Y  

Y  

N  

N  

N  

N  

Y