Chery QQ6 (S21) / S12LHD. Manual — part 103

pressure difference between the inlet and the outlet of the canister control valve. The canister control

valve will be closed when there is not any electric pulse.

12.4 Installation attentions

See above installation drawing for connection among canister control valve, carbon canister and

intake manifold.
l In order to avoid transfer of solid borne noise, floating installation of the canister control valve

on the hose is recommended.

l During installation, make sure that the airflow direction meets the specification.
l Appropriate measures such as filtering and purge etc. must be taken to prevent such foreign

material as particles from entry into the canister control valve from carbon canister or hose.

It is recommended that a corresponding protective strainer (size of grid

<

50

µ

m) should be

installed on outlet of carbon canister.

12.5. Failure effects and judgment method
l Failure effects: Failure of functions etc.

Reasons for general failure: corrosion or poor sealing performance etc. due to entry of foreign

material into inside of the valve.
l Maintenance precautions:

1. During installation, make sure that the airflow direction meets the specification;

2. In case of control valve failure due to black particle inside the valve body, when replacement

of the control valve is required, check the status of the canister;

3. During maintenance, try to avoid entry of such liquid as water and oil etc. into the valve;

4. In order to avoid transfer of solid borne noise, floating installation of the canister control

valve on the hose is recommended.

87# pin of main relay

Canister control valve

1 From fuel tank

2 Canister

3 Atmosphere

4 Canister control valve

5 To intake manifold

6 Throttle

Cross-section view of

canister control valve

Installation drawing of canister control valve

ΔP is the difference between environmental pressure
Pu and intake manifold pressure Ps

l Simple measurement method:

With the joint removed, turn the digital multimeter to Ohm shift, and then connect the two

meter pens respectively to both pins of the canister control valve. The rated resistance at 20

should

℃

read 26±4Ω.

13. Electronic Accelerator Pedal

13.1 Function:

The electronic accelerator pedal has cancelled the conventional throttle guy and the position of

accelerator pedal is fed back to ECU by means of electronic signal, through which ECU can

calculate and control the action of the electronic accelerator pedal. Two sets of Hall sensors are

integrated in the pedal; ECU can compare and analyze the two signals, if one signal is improper,

ECU will duly access the other signal and light the failure indicator.

13.2 Working principle:

The pedal is a Hall sensor. The fixed Hall generator and signal processing circuit are installed

on fixed mounting of the pedal. The two permanent magnets with different magnetic sheet thickness

act together with the pedal. When the pedal acts, the magnetic flux passing the Hall generator will

also change accordingly, the signal processing circuit will process these signals and then send them

to ECU.

13.3 Detection:

The relationship between the two signals of the accelerator pedal is that signal 1 is equal to

signal voltage.

At idle speed position, the voltage of signal 1 is 4.59 and that of signal 2 is 4.30. When the

pedal is at middle position, the voltage will be the minimum; when the pedal is at either end position,

the voltage will be the maximum.

14. Three-way Catalytic Converter

14.1 Function:

Three-way catalytic converter is used to convert the noxious gas in tail gas into such innocuous

gases as carbon dioxide and water etc. At 300-800

, the conversion efficiency of three

℃

-way

catalytic converter is maximum; with a temperature below this scope, the conversion efficiency will

be very poor, while, with a temperature above this scope, the three-way catalytic converter may be

burnt out. Three-way catalytic converter can exert better conversion efficiency only when the

oxygen sensor works. In control strategies of ECU, there are several protective modes for three-way

catalytic converter, and ECU can protect the three-way catalytic converter by regulating air-fuel ratio

and ignition advance angle.

15. Fan Control

15.1 Function:

In order to abstract heat from engine system and from condenser with A/C turned on, fan

control is affected by the signal to ECU sent by water temperature sensor; When water temperature

is high (above the threshold value set by ECU), the fan will run, and when water temperature is low

(below the threshold value set by ECU), the fan will also run; with A/C turned on, the fan will run at

low speed.

15.2 Composition:

DC electric motor double fan (high and low speed change).

15.3 Installation requirements:

The fan is installed between the rear of radiator and the engine, be careful when installing: not

to damage fin of fan blade, otherwise, running noise of the fan will increase, if serious, it may lead to

sharp fall of heat radiation effect of the engine.

15.4 Failure diagnosis:

Fan control circuit is a short or open circuit to ground;

The fan has failure itself;

Too loud fan noise;

Failure in power supply circuit of fan.

15.5 Troubleshooting:

First, validate whether it is a high speed fan system problem or a low speed fan system problem.

Provided that this is a fan control system problem, use a diagnostic tester to locate the failure point,

and then validate whether it is a short-circuit or a break in control circuit.

Failure symptom: the fan failure may result in rise of engine coolant temperature and poor

refrigeration of A/C system.

15.6. Fan Control:

Turn-on of low gear of fan:

1. Temperature of engine coolant: 96℃-102

;

℃

2. On request for A/C, the fan will start up;

3. When driving speed is too high, the fan will start up;

High speed startup of fan:

1. Engine coolant temperature sensor failure;

2. Air flow meter failure;

3. Engine coolant temperature exceeds 102

.

℃

Pins:

Main relay

High

speed

relay of fan

Low

speed

relay of fan

Brief sketch map of fan control

Fan motor

1. High speed fan control (corresponds to ECU50#);

2. Low speed fan control (corresponds to ECU68#);

The operating mode of fan after engine stops:

1. Failure of intake air temperature sensor of engine, delay 60s;

2. Failure of intake air temperature sensor of engine, delay 60s;

3. Engine coolant temperature exceeds 100.5

, delay 60s;

℃

4. Engine coolant temperature exceeds 70.5

, delay 60s.

℃

16. Position Sensor of Double Brake Pedal

16.1 Function:

制动开关传感器是将刹车信号送给 ECU，ECU 根据（原文不全）

16.2 Working principle:

Inside the brake switch, there are two mutually independent switches with one normal close and

the other normal open. After applying the accelerator pedal, the former normal close switch turns to

be normal open, while the normal open one turns to be normal close. Both signals will be sent to

ECU to be used to control other systems. Whenever the two signals disaccord, ECU will enter failure

mode, the electronic throttle will not respond when applying the accelerator pedal and the engine

will maintain idle speed working state.

Composition: the double brake switch is installed on the bracket of the brake pedal and contains two

independent switches inside.

Installation requirement: the assembly is installed on the pedal and there is a thread adjusting

mechanism on the switch for stroke adjustment of the switch and effective stroke adjustment of the

brake switch.

17. Clutch Position Sensor

17.1 Function:

Long flame (30)

Main power supply (15)

Double brake switch