Chery A11. Manual - part 118

coolant temperature reaches specified value (about 65℃). When engine warming up, ECU 

will send a square wave signal to carbon canister.    Carbon canister on and off is regulated 

by cycle ratio of signal itself. Therefore ECU may control fuel vapor quantity input to 

intake manifold, preventing mixture richness making an abrupt change.   

 

 

When throttle is at idle position, engine speed less than 1500 rpm, intake manifold pressure 

lower than a preset value and air/fuel mixture richness self-adapt, carbon canister solenoid 

keep closed to ensure an more optimum engine performance. 

      (3) Fuel tank ventilation safety valve 

        it has the following functionsThe valve is installed on filter cover and has following 

functions upon pressure inside fuel tank: 

1. When pressure inside fuel tank exceeds 0.1—0.18bar, fuel vapor will be given out from 

outlet (safety function).   

    2. When 0.020—0.030bar vacuum is generated in the fuel tank, air is drawn in 

(ventilation function) 

6. Engine anti-theft system (optional)The engine anti-theft unit is an alien frequency radar 

anti-theft unit. 

 

Fig 13 Engine anti-theft unit schematic 

1. Anti-theft  ECU (ignition key)    2. Engine  ECU    3.Anti-theft  unit  ECU 

The alien frequencies radar anti-theft system is an electric device, connecting with engine 

control system, prevent vehicle  from  disoperation. One of characteristics engine 

anti-theft    unit on and off need no additional operation by user. When use alien frequency 

radar    transponder, the function is on as the key turns off and the function is off as the key 

turns on. Each time the key turn on, the engine ECU needs a special authentication code. 

The authentication code is processed    upon code stored in ignition switch circuit. Only this 

condition meets can the engine start. 

        Alien frequency radar anti-theft unit mainly consists of 3 components: anti-theft ECU, 

antenna and transponder. 

Anti-theft unit ECU is in a black plastic box and usually located on instruments panel. 

Its electric device is in-line with alien frequency radar transponder and connects with engine 

ECU. Antenna is fixed in a special channel in ignition switch and consists of copper coil 

wrapped by a plastic jacket and a connector, which can connect with anti-theft ECU. The 

 

structure of anti-theft ECU is as shown in fig 14. 

 

 

 

Fig 14  Anti-theft ECU 

Anti-theft ECU pin definition 

8-pin connector 

3-pin connector 

1 Not 

used 

1 

Antenna 

positive 

2 

warning indicator 

2 

not used 

3 +30(12V) 

3 

Antenna 

negative 

4 ground 

   

5 Not 

used 

   

6 

to ECU serial surface 

 

 

7 Not 

used 

   

8 

+15 (ignition switch 

positive) 

 

 

  Warning indicator 

Warning indicator on instruments panel is controlled by anti-theft ECU, indicating user 

state information. Warning indicator will flicker under following conditions: 

1.  The key is stored; 

2.  2.5 seconds after the key turned on, the warning indicator begins to flicker, indicating 

system is operating but engine will not be protected until the key is stored. 

5.    Electronic Control Fuel Injection System Maintenance 

        (1) Fuel 

ONLY high quality vehicle unleaded gasoline of RESEARCH RULE octane value 

RON90 or above (conform to SH0041 standard, lead content〈=0.005g/L〉, otherwise, the 

electronic control fuel injection system and 3 way catalyst converter will be damaged, 

affecting exhaust performance.. In addition, sulfur or lead can damage heated oxygen 

sensor. 

        (2) Start-up 

The electronic control fuel injection system can provide appropriate injection fuel width 

under all conditions. Therefore depressing pedal is not necessary before or after hot or cold