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Chery B11. Manual - part 74

Chery Automobile Maintenance Manual

Note

Barometric pressure sensor is embedded

in airflow sensor, so refer to airflow

sensor connector for the joint terminal

of barometric pressure sensor.

Sensor Plug

Measure airflow sensor connector

Connect cable MB991709 between

terminals

Voltage between 2# terminal and ground

(Ignition switch ON)

Normal Status: 3.7

4.3V(Altitude Height:

0m)

3.2

3.8V(Altitude Height: 1200m)

Abnormal Measure airflow sensor harness joint.

Disconnect connector and measure

wiring side

1. Voltage between 1# and ground (Ignition

switch ON)

Normal status

4.8-5.2V

2. Conductivity between 5# and ground

Normal status

Conductible

Abnormal

Normal

Check airflow sensor connector

Abnormal

Normal

Check failure

Abnormal

Check wiring between barometric
pressure

ensor and check ECU

Abnormal

Repai

Normal

Replace airflow sensor

Check harness D zone joint

Abnorma

Repair

Normal

Check failure

Abnormal

Check the harness between

barometric pressure

sensor and ECU

Abnormal

Repai

Normal

Repai

Replace engine ECU

Norm

Check D zone connector of engine ECU

Connect connector

Voltage between D15# terminal and ground

(Ignition switch ON)

Normal Status: 3.7-4.3V(Altitude Height: 0m)

3.2-3.8V(Altitude Height: 1200m)

Normal

Check D connector of engine ECU harness

Abnormal

Repai

Norma

Check failure

Abnormal

Replace engine ECU

Abnormal

Check harness between

barometric

pressure sensor and engine ECU. If

necessary, repair it.

Chery Automobile Maintenance Manual

V. Idle Speed Motor

1. Idle Speed Motor Component
Position Figure

To keep idle speed status and operation

load of engine stable, stepper motor is moving
forward or backward according to pre-defined
control status, which controls the airflow
through throttle and keeps idle speed at best
status.

ISC system is in control and actual idle

speed is calculated by ECU. If actual idle speed
is different from target idle speed, you may
drive stepper motor speed feedback control in
order to adjust actual speed to target speed.

In order to process the load of air

conditioners etc., stepper motor (STM) position
control also may drive stepper motor to target
position.

Check
(1)Action sound check

Confirm engine coolant temperature is

below 20

Note: If engine coolant temperature is

above 20

, you may remove the harness joint

of engine coolant temperature sensor and
connect another coolant temperature sensor
which is below 20

with it.

When ignition switch is turned to ON

(don’t start on engine), check if there is action
sound from stepper motor.

If there is no action sound from stepper

motor, please check the drive circuit of stepper
motor. If drive circuit is OK, it maybe caused
by the defect of stepper motor or engine ECU.

(2)Coil resistance check

Standard Value:28-33 (at 20

)

Idle Speed Motor

EGR valve

Chery Automobile Maintenance Manual

VI. Throttle Body Structure

There are 3 inlet tubes of throttle body.
The airflow volume of main inlet tube is

controlled by throttle. The throttle axle is
connected to throttle sensor (throttle position
sensor and idle speed switch). The throttle
position change is turned into electric signal by
sensor and transferred into ECU.

The other two inlet tubes are bypass inlet

tubes. The airflow of one bypass inlet tube is
adjusted by helical pin valve. The airflow of the
other bypass inlet tube is adjusted by pin valve
driven by stepper motor and protected by
coolant temperature control valve.

Engine idle speed is controlled by ECU.

The pin valve is driven by stepper motor, which
may adjust airflow. No manual adjustment is
required.

The airflow is controlled by the position of

helical pin valve in bypass tube.

Because engine idle speed is controlled by total
airflow, the airflow of each tube affects each
other. Stepper motor is a mechanism that
controls airflow during engine idle speed
running, so it can’t be closed. If new engine is
running at idle speed (no load on engine), the
frequency of stepper motor is about 20 steps,
while after running-in, if it is running at idle
speed (no load on engine), the frequency of
stepper motor is about 10 steps.

Chery Automobile Maintenance Manual

VII. Throttle Body Cleanness

Throttle Body Cleanness

Start and preheat engine until
coolant temperature reaches 80

more, and then stop engine.

Remove inlet soft tube from throttle
body.

Stem bypass induction port of throttle
body.

Note

Don’t let cleanser into bypass

tube.

Inject the cleanser into valve through
throttle body induction port and keep
for 5 minutes.

After starting engine, racing several
times at high speed and then running at
idle speed for 1 minute. If instable idle
speed or engine flameout due to
stemmed bypass tube, you can open
throttle partially, which make engine
run well.

If deposit inside throttle fails to be
cleaned up, please repeat step (4) and
(5).

Pull out the plug of bypass inlet port.

Connect inlet soft tube.

Clear diagnostic code with MUT-II.

Adjust basic idle speed.

Note: If there is interrupted vibration during
engine running at idle speed after basic idle
speed adjustment, please keep battery
cathode disconnected for more than 10
seconds and then re-connect it, the engine
run at idle speed for about 10 minutes.

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