Chery QQ6 (S21) / S12LHD. Manual — part 112

Yes

Replace fuel pump

12

Check if the fuel pump is stopped up.

No

Replace ECU

Note: Warm starting difficulty is in connection with many systems, such as battery,
throttle body and water temperature sensor etc. as well as mechanical part of the engine,
such as valve sealing. Thermal expansion of engine under warm state may lead to rise of
engine resistance.

12.5 Engine Speed is Normal, but it is Difficult to Start at any Time

No.

Operating steps

Result

Follow up steps

Yes

Remove the failure

displayed

1

Put the ignition switch to “ON”. Use a special

diagnostic tester to check if any failure

information record exists.

No

Next step

Yes

Next step

2

Check the air cleaner and look if it is open.

No

Replace

Yes

Next step

3

After starting successfully, check if air intake

consumption of the engine at idle speed is

around 300Kg/h (remember to check if cylinder

pressure is normal).

No

Eliminate

the

failure of air intake

system leaking

4

Step on the throttle slightly and observe if it is

easy to be started easily.

Yes

Replace

the

electronic

throttle

body

Yes

Next step

5

Connect fuel manometer valve. Short 30#, 87#

pins of fuel pump relay to make the fuel pump

run, and then check if fuel pressure is around

400kPa.

No

9

Yes

8

6

Use a special joint to directly supply a 12V

voltage and intermittent ground wire from

battery to injector and check if the injector

works normally (work intermittently).

No

Next step

Yes

Next step

7

Clean out the fuel injector and look if it can

work correctly.

No

Replace

fuel

injector

Yes

Replace fuel

8

Replace fuel 8, and check if the fuel is

deteriorated or moisture.

No

14

Yes

Next step

9

Check if the fuel pressure value is below 300

kPa.

No

13

Yes

Next step

10

Close the fuel manometer valve. Re-engage the

ignition switch to let the fuel pump run for 3s,

and then check if fuel pressure can be built up.

No

12

Yes

Replace

fuel

pressure regulator

11

Open the valve of fuel gauge and clamp the oil

return pipe by oil return baffle so that the oil can

not return. Check if the oil pressure occurs

immediately.

No

Repair and replace

fuel injector and oil

pipe

Yes

Repair or replace

oil intake pipe

12

Check if there is leaking or jam in oil intake

pipe.

No

Replace oil pump

13

Check if the oil return pipe is bended or

jammed.

Yes

Repair or replace

oil return pipe

No

Replace

fuel

pressure regulator

Yes

Next step

14

When engine coolant is at low temperature, pull

out electronic throttle body on harness and

observe if engine revolution will rise.

No

Check

electronic

throttle body for

damage

Yes

Next step

15

Put the ignition switch to “ON”. Check if

voltage on the following pins of ECU is normal:

if it is a battery voltage around 12V on 12#, 14#,

15# pins; if the voltage between 51#, 53#, 3#,

61#, 80# pins and the wire is zero.

No

Check wires and

plugs

Yes

Next step

16

Check if ignition advance angle is normal.

No

Check

other

systems

Yes

Next step

17

Check if cylinder compression pressure of

engine is normal, if low, add a little engine oil

into each cylinder and re-measure if the cylinder

pressure is normal.

No

Troubleshooting

Yes

Repair or replace

18

If air cleaner or airflow sensor is choked.

No

Next step

Yes

Replace ECU

19

Check if the coolant temperature sensor is

working correctly.

No

Repair or replace

Note: Note if theft-proof system has started up. After theft-proof system has started up,
when starting the engine, the staring motor can run normally, but the engine can not
start; therefore, please note if this system can work normally.

12.6 Cold Starting Difficulty

No.

Operating steps

Result

Follow up steps

Yes

Remove the failure

displayed

1

Put the ignition switch to “ON”. Use a failure

diagnostic tester to check if any failure

information record exists.

No

Next step

Yes

Next step

2

Use a multimeter to check if the coolant

temperature sensor is normal. (A 2.8KΩ electric

resistance can also be connected in series between

39# and 17# pins of ECU to start the engine in

stead of the coolant temperature sensor. If the

engine can start, it indicates off normal of coolant

temperature sensor.)

No

Replace the sensor

Yes

Next step

3

Put the ignition switch to “ON”. Check if voltage

on the following pins of ECU is normal: if it is a

battery voltage around 12V on 12#, 14#, 15# pins;

if the voltage between 51#, 53#, 3#, 61#, 80# pins

and the wire is zero.

No

Check wires and

plugs

Yes

Next step

4

Check the air cleaner and look if it is open.

No

Replace

Yes

Next step

5

After starting successfully, check if air intake

consumption of the engine at idle speed is around

300Kg/h (remember to check if cylinder pressure

is normal).

No

Eliminate

the

leakage failure of

air intake system

Yes

Check

the

electronic throttle

6

Step on the throttle slightly and observe if it is

easy to be started easily.

No

Next step

Yes

Next step

7

When engine coolant is at low temperature, pull

out electronic throttle body joint on harness and

observe if engine revolution will rise.

No

Check the electric

throttle body

Yes

Next step

8

Connect fuel manometer valve. Let 86# pin of fuel

pump relay directly ground. Turn on ignition

switch to make fuel pump relay and fuel pump

work, and then check if fuel pressure is at around

400kPa.

No

12

Yes

11

9

Use a special joint to directly provide a 12V

electricity and ground wire from battery to injector

and check if the injector works normally.

No

Next step

Yes

Next step

10

Clean out the fuel injector and look if it can work

correctly.

No

Replace

fuel

injector

11

Check if fuel is deteroprated or moisture.

Yes

Replace fuel