Chery A21 2005, Service Manual, Page: 266 / 475

（ 1 ）
Fault descriptio n:
Fault analysis ：
Troubleshoot :
Badness idle speed, badness acceleration, badness tail gas, over fuel
consume etc.
Moisture enterin g inside of sensor, then the temperature is ch anged and the pin is broken;
the sensor is poisoned （ Pb,S,Br,Si ）
Disassemble joint ， Put digital multimeter to ohm shift, connect meter pen to No.1
（ white ） and No.2 （ white ） pins of the sensor. Normally the resistance value is 1~6 Ω .
（ 2 ） Connect the joint and keep it at idle speed status. When the oxygen sensor reaches to
its working temperature 350 ℃ , keep digital multimeter to DC volt shift and connect meter pen to
No.3 （ gray ） and No.4 （ black ） pins of sensor. Now the voltage should be fluctuate between
0.1- 0.9V quickly （ the data also can be gotten from data flow inspected by diagnosis meter ） .
ECU
1 2
3
59
T he 1st pin of the vehicle speed s ensor connect t o power
T he 2nd pin conn ect to ground
T he 3rd pin is the vehicle speed s ignal, it connec t to the
59 th pin of engine ECU.
60 75
Br/B V/W
2 3
4 1
High/Low
pressure Switch
To The
Air Conditioner
Module B19 (AC Switch)
ECU
（ 8 ） Vehicle speed sensor
Figure9-12 Ve hicle spee d sensor and its circ uit
（ 9 ） A/C pressure switch
Figure9-13 A/C pressure switch and its ci rcuit
（ 10 ） Clutch pedal switch
74
Sb/B
ECU/A1/7
Clutch
Pedal
Switch
ECU
The 1st pin of clutch pedal swit ch is connectted
to the 74 th pin of ECU, and the other pin is
connect ted to ground.
Figure9-14 Clutch pedal switch and its circuit
（ 11 ） Power steering switch
The 1st pin of the power steering
switch is connectted to the 76th
pin of engine ECU, and the
other pin is connectted to ground.
Figure9-15 Power Steering switch and its circuit
Vehicl e speed sensor
To fuse FB5
Vehicle speed sensor
A/ C high/low pressure
switch
In stallation position of
power steering switch
Clutch pedal switch
The 2nd pin of A/C high/l ow pressure switch connect to the 75th pin of ECU; the 3rd pin conne ct to the
60th pin of ECU; the 1st 4th pin connect to the B19 switch of A/C module.
、
18
76
L
Power
Steering Switch
E CU