Chery A11. Manual — part 158

Maintenance Manual for Chery·Windcloud

Marelli EFI System

C. Check spark plug to see if clearance is proper;
D. Check high voltage wire to see if resistance is

too high;

E. Check intake conduit to see if it is worn out,

etc.

No

Diagnosis
Instruction

Failure: too high circuit voltage of upstream oxygen sensor

Step Operation

Result Solution

1

Connect scanner and commutator, and then turn
ignition switch to “ON”.

Go to next step

Yes

Diagnosis
Instruction

2

Start engine and idle it until coolant temperature is
normal. Observe Oxygen Sensor Voltage to see if
the indication quickly changes between
100mV-900mV (at least 5 changes within 10
seconds).

No

Go to next step

Yes

Repair or
replace wire
harness

3

Check respectively the connections between Pin 20
of ECU and Pin A of sensor connector, Pin 9 of
ECU and Pin B of sensor connector (two thin wires
on ECU wire harness, the two thick wires are
heating coils) to see if they are short circuit to
power.

No

Diagnosis
Instruction

Failure: signal error of upstream oxygen sensor

Step Operation

Result Solution

1

Connect scanner and commutator, and then turn
ignition switch to “ON”.

Go to next step

Yes

Diagnosis
Instruction

2

Start engine and idle it until coolant temperature is
normal. Observe Oxygen Sensor Voltage to see if
the indication quickly changes between
100mV-900mV.

No

Go to next step

Yes

Repair or
replace wire
harness

3

Check respectively the connections between Pin 20
of ECU and Pin A of sensor connector, Pin 9 of
ECU and Pin B of sensor connector (two thin wires
on ECU wire harness, the two thick wires are
heating coils) to see if open circuit occurs.

No

Diagnosis
Instruction

Failure: heating circuit error of upstream oxygen sensor

Step Operation

Result Solution

1

Connect scanner and commutator, and then turn
ignition switch to “ON”.

Go to next step

20

Maintenance Manual for Chery·Windcloud

Marelli EFI System

Yes

Go to next step

2

Unplug oxygen sensor connector from wire harness,
and check the voltage between Pin C
(corresponding to white wire of oxygen sensor) and
Pin D (corresponding to white wire of oxygen
sensor, two thick wires on ECU wire harness) of the
connector with a multimeter to see if it is around
12V.

No

Go to Step 4

Yes

Go to next step

3

Check the resistance between Pin C (white) and Pin
D (white) of oxygen sensor with a multimeter to see
if it is around 4.5Ω (23 ± 5°C).

No Replace

sensor

Yes Replace

fuse

4

Check the 10A fuse in oxygen sensor heating circuit
to see if it is blown.

No

Go to next step

Yes

Repair or
replace wire
harness

5

Check respectively the connections between Pin 28
of ECU and Pin C (corresponding to white wire of
oxygen sensor) of sensor connector, Pin 87 of main
relay and Pin D (corresponding to white wire of
oxygen sensor) of sensor connector to see if open or
short circuit to power/ground occurs.

No

Diagnosis
Instruction

Failure: self-adaptation of air fuel ratio closed-loop control exceeds upper

limit

Step Operation

Result Solution

1

Connect scanner and commutator, and then turn
ignition switch to “ON”.

Go to next step

Yes

Go to next step

2

Start engine and idle it until coolant temperature is
normal. Observe Oxygen Sensor Voltage on scanner
under all working conditions to see if the value
indication maintains stable around 100mV under
some working conditions for a long time.

No

Diagnosis
Instruction

Yes

Go to next step

3

Connect a fuel pressure gauge to fuel inlet pipe of
fuel system and observe fuel pressure under all
working conditions to see if it is around 350kPa.

No

Check and
repair fuel
system

Yes

Repair or
replace wire
harness

4

Check respectively the connections between Pin 20
of ECU and Pin A of sensor connector, Pin 9 of
ECU and Pin B of sensor connector (two thin wires
on ECU wire harness, the two thick wires are
heating coils) to see if they are short circuit to
ground.

No

Go to next step

21

Maintenance Manual for Chery·Windcloud

Marelli EFI System

5

A. Check intake system for severe air leakage;
B. Check injectors for blockage;
C. Check spark plug to see if clearance is proper;
D. Check sub live wire to see if resistance is too

high;

E. Check valve clearance to see if it is proper, etc.

Yes

Repair as per
diagnosis

Failure: self-adaptation of air fuel ratio closed-loop control exceeds lower

limit (too thin)

Step Operation

Result Solution

1

Connect scanner and commutator, and then turn
ignition switch to “ON”.

Go to next step

Yes

Go to next step

2

Start engine and idle it until coolant temperature is
normal. Observe Oxygen Sensor Voltage on scanner
under all working conditions to see if the value
indication maintains stable around 900mV under
some working conditions for a long time.

No

Diagnosis
Instruction

Yes

Go to next step

3

Connect a fuel pressure gauge to fuel inlet pipe of
fuel system and observe fuel pressure under all
working conditions to see if it is around 350kPa.

No

Check and
repair fuel
system

Yes

Repair or
replace wire
harness

4

Check respectively the connections between Pin 20
of ECU and Pin A of sensor connector, Pin 9 of
ECU and Pin B of sensor connector (two thin wires
on ECU wire harness, the two thick wires are
heating coils) to see if short circuit occurs.

No

Go to next step

Yes

Repair as per
diagnosis

5

A. Check injector for leakage;
B. Check exhaust pipe for leakage;
C. Check ignition timing to see if it is proper;
D. Check intake conduit to see if it is worn out;
E. Check valve clearance to see if it is proper; etc.

No

Diagnosis
Instruction

Failure: injector circuit error in Cylinder 1

Step Operation

Result Solution

1

Connect scanner and commutator, and then turn
ignition switch to “ON”.

Go to next step

Yes

Go to Step 4

2

Unplug Cylinder 1 injector connector from wire
harness, check the voltage between Pin 1 of the
connector and cathode of power supply with a
multimeter to see if it is around 12V.

No

Go to next step

22

Maintenance Manual for Chery·Windcloud

Marelli EFI System

Yes

Repair or
replace wire
harness

3

Check the connection between Pin 1 of Cylinder 1
injector connector and main relay to see if open or
short circuit to ground occurs.

No

Go to next step

Yes

Go to next step

4

Check the resistance between Pin 1 and Pin 2 of
Cylinder 1 injector with a multimeter to see if it is
around 11-16Ω at 20℃.

No

Replace
injector

Yes

Diagnosis
Instruction

5

Check the voltage between Pin 2 of Cylinder 1
injector connector and cathode of power supply
with a multimeter to see if it is around 3.7V.

No

Go to next step

Yes

Repair or
replace wire
harness

6

Check the connection between Pin 2 of Cylinder 1
injector connector and Pin 71 of ECU to see if open,
short circuit to power/ground occurs.

No

Diagnosis
Instruction

Failure: injector circuit error in Cylinder 2

Step Operation

Result Solution

1

Connect scanner and commutator, and then turn
ignition switch to “ON”.

Go to next step

Yes

Go to Step 4

2

Unplug Cylinder 2 injector connector from wire
harness, check the voltage between Pin 1 of the
connector and cathode of power supply with a
multimeter to see if it is around 12V.

No

Go to next step

Yes

Repair or
replace wire
harness

3

Check the connection between Pin 1 of Cylinder 2
injector connector and main relay to see if open
circuit or short circuit to ground occurs.

No

Go to next step

Yes

Go to next step

4

Check the resistance between Pin 1 and Pin 2 of
Cylinder 2 injector with a multimeter to see if it is
around 11-16Ω at 20℃.

No

Replace
injector

Yes

Diagnosis
Instruction

5

Check the voltage between Pin 2 of Cylinder 2
injector connector and cathode of power supply
with a multimeter to see if it is around 3.7V.

No

Go to next step

Yes

Repair or
replace wire
harness

6

Check the connection between Pin 2 of Cylinder 2
injector connector and Pin 79 of ECU to see if open,
short circuit to power/ground occurs.

No

Diagnosis
Instruction

23