Chery S11 / Chery QQ. Manual — part 226

Chery QQ Maintenance Manual 465 EFI System

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Chapter 1 The principle for

EFI and actuator

1. Intake air pressure and intake
temperature sensor
Usage: Measure baro pressure equal or
below 115kPa in manifold and intake air
temperature to supply load information for
engine.
Constitute and pricinple:The sensor consists
of two sensors, MAP and IAT, which
mounted on voltage stablizer box.
MAP: Map consists of one silicon chip that
etched a film on the chip. There are 4
piezoelectric resistances that consist of a
Wiston bridge. The information processing
circuit is also on the chip. The chip consists
of closed reference space with a metal shell.
The air absolute pressure in the space is
nearly to zero. In this way, a micro
electric-mechanic system is formed. The
active face of the chip is endured a pressure
nearly to zero, and MAP pressure applies on
the back of the chip through a connecting
pipe. The thickness of the chip is only
several microns（ um），so the change of
MAP pressure will result the mechanical
deform for the chip together with 4
resistances to change their resistance. The
voltage signal that is linearity with pressure
is formed after processing by information
processing circuit in the chip.
Intake air pressure: IAT is a resistor with
NTC. Like coolant temperature sensor, the
resistance decreased with the temperature
increasing. ECU in engine monitors the
change of intake air temperature
(corresponding in series circuit).
Diagnosis: The open, short or wear of sensor
could be detected by the rear electronic unit
of MAP.
ECU will judge the malfunction of sensor if

the out put signal exceeds the signal outside
the curve of output feature. For example, if
the intake air pressure is higher than the up
limit or lower than lower limit,ECU will
judge that sensor is malfunction ( The intake
air pressure is below lower limit in starting,
but ECU can judge starting condition),
“CHECK ENGINE”light will on at same
time and engine will run at malfunction
mode.

MAP/IAT

The circuit for MAR/IAT
Pins: No.1 Ground
No.2 Output signal of temperature
No.3 To 5V

Chery QQ Maintenance Manual 465 EFI System

No.4 Output pressure signal

The section plane of MAP/IAT
1. Seal 2. Stainless steel bush
3. PCB plate 4. Sensor 5. Shell
6. Support 7. Welding connection
8. Felt connection

2. TPS
Usage: TPS is used to supply Throttle angle
signal. According to this signal, ECU will
receive engine load signal and working
condition signal such as starting, idle, back
up, partial load, and full load) as well as
acceleration and deceleration signal.
Constitute and pricinple:TPS is a angle
sensor with linear output. It consists of 2 arc
slide resistors and 2 slide arms. The shaft of
arm and throttle shaft connect to one axes.
When running throttle, arm run together and
slides on resistor. Putout UP as output
voltage. So it is a angle potentiometer.
Diagnosis: ECU check if throttle angle
exceeds the up limit or lower limit of output
signal. If so, ECU will judge TPS
malfunction, engine will run at malfunction
mode, MIL will on (Knock sensor or dirty
will cause engine malfunction).
Install: Screw torque for bolts:
1.5Nm-2.5Nm

Out view of TPS

Diagram of TPS

Pins: Run throttle counterclockwise (see
from one side of sensor on shaft into
throttle):1.Ground 2. 5V source 3. 5V
source

3. Coolant temperature sensor TF-W
Usage: ECT is used to supply Coolant
temperature information for the timing and
fuel inject pulse width control on engine
start, idle, normal running.
Constitute and principle: ECT is a thermal
sense resistor with NTC. The resistance
decreases with coolant temperature increases,
but it is not in linearity. The resistor is
enclosed in copper bush. The change of
resistance is transformed into changing
voltage to ECU by a voltage distribute
circuit to monitor the change of water
temperature.
Diagnosis: When coolant temperature is
over up limit, or below lower limit, MIL is
on, engine run at malfunction mode. ECU
control ignition and fuel inject according to
set temperature. Fan runs at high speed.
Limit data: 2.5±5%KΩ
Hint: Screw torque: 15±2Nm
Hint: There are 2 sensors in vehicle. One is
single pin water temperature and supply
water temperature signal for water temp
meter; The other is double pins and supplies
the temp signal to ECU.

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Chery QQ Maintenance Manual 465 EFI System

Diagram of ECT

The diagram of coolant tem sensor
Pins: There are 2 pins that could be
inter-exchangeable.

Coolant temp sensor

1. Connector 2. Sleeve 3. NTC resistor

4. KS
Usage: Supply knock signal to ECU for
knock control.
Constitute and principle:
KS is vibration acceleration sensor mounted

on engine. The sense element is a
piezoelectricity element. The vibration of
cylinder is transformed to piezoelectric
crystal through mass block in sensor. The
pressure of crystal produce voltage on two
polar faces and change vibration signal into
output AC voltage signal. Because the
frequency of vibration caused by engine
knock is much higher than normal frequency
of engine vibration signal, so ECU can
distinguish knock and non-knock signals
after filtering the signal of KS. When engine
load, speed and coolant temperature exceed
gate value, and not set KS malfunction
information record, the signal of KS will be
used to close loop control for knocking.
When the control is actuated, the signal of
KS will input to ECU for integral after
amplify and filter. When certain integral
value in crank angle exceeds gate value,
ECU will consider the knock happens, and
reduce 1 degree of ignition advanced-angle.
If knock happens on next cycle, ECU will
reduce 1 degree of ignition advanced-angle
again; If no knocks happen in next cycles,
ECU will resume the angle to normal value.
Diagnosis: ECU monitors each sensor,
actuator, power amplifier and check circuit.
KS will mark malfunction position once
following situations happen:

KS malfunction
KS control data process circuit

malfunction

Cylinder identification signal is

non-trustable
After KS marks the malfunction position,
knock close loop control will shut off and
reduce 1 safety degree for ignition
advanced-angle stored in ECU. When wrong
frequency is below set value, malfunction
position will resume.
Hint: Screw torque 20± 5Nm

.

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Chery QQ Maintenance Manual 465 EFI System

KS with cable

The diagram of KS

Pins: pin 1 and pin 2 connect ECU, pin 3
connects shield.
The shield wire of sensor is folded on
outside of signal wire and connects to pin
19 on ECU. All shield wires on shielded
sensors connect to pin 19 on ECU.

5. Oxygen sensor
Usage: The sensor is used to supply the
information that if oxygen is superfluous
after the fuel in cylinder combusted
completely in intake air.ECU uses the
information to close-loop control for
quantitative fuel and transforms or purifies

three venomous ingredients such as HC, CO
and NOX in catalyzer.
Constitute and principle: The sense element
is a ceramic pipe with bores. The outside of
pipe is surrounded by exhaust of engine, and
inside is touched with atmosphere. The pipe
wall is one kind of solid electrolyte with
electric heating pipe in it to heat ceramic
body to 300 Cº for ceramic body to work.
The oxygen ion can pass pipe freely.
The concentration differential is transformed
into electric differential with this feature to
form electric signal. If mix air is richer,
electric differential and output voltage are
higher; if mix air is leaner, electric
differential and output voltage are lower.
The working voltage of sensor fluctuates
between 0.1-0.9V with 5-8 times every 10
seconds. Sensor is aging if the frequency is
below this value and needs replacing. The
sensor cannot be repaired.
Diagnosis: ECU monitors each sensor,
actuator, power amplifier and check circuit.
ECU will mark the malfunction position
for oxygen sensor once one of following
situations happen:
Battery voltage is not trustable.
MAP signal is not trustable.

Coolant temperature signal is not

trustable.
Injector driver is fault.
After marking malfunction position for
oxygen sensor, fuel ration close-loop
control will shut off and will be carry on
according to basic inject time stored in
ECU.
Install hint: The screw torque of sensor
is 50-60Nm. Smear anti-corrosion oil on
the sensor after replacing.

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