Chery Tiggo T11 LHD. Manual — part 65

Chery T11 Service Manual Electric Injection System

73

6) Unstable idle at any time

No.

Operation Step

Detection

Result

Subsequent Step

1

Place the ignition switch on the “ON” position, and apply the

failure diagnosis instrument to examine and confirm whether

there are some failure information records.

Yes

Remove

the

displayed

failure

No

Next step

2

Examine and confirm whether the stepper motor idle actuator is

seized.

Yes

Repair or

replace the idle

actuator

No

Next step

3

Turn on the ignition switch, and examine and confirm whether

the connecting wires among the water temperature sensor, idle

stepper motor and ECU are normal.

Yes

Examine

harness and

connecting parts

No

Next step

4

Enable the engine to operate at idle speed, shut down these

cylinders one by one, and view whether the engine speed

decreases and fluctuates.

Yes

8

No

Next step

5

Examine and confirm whether the operating condition of fuel

injector of any cylinder is normal.

Yes

Next step

No

Examine the

fuel injector and

harness

6

Examine and confirm whether the resistance value of

high-voltage wire of any cylinder is normal.

Yes

Next step

No

Replace

7

Examine and confirm whether the ignition switch is damaged.

Yes

Replace

No

Next step

8

Examine and confirm whether the sparkle plug is normal.

Yes

Next step

No

Replace sparkle

plug

9

Connect the fuel pressure gage valve. Short circuit the No 30

and 87 pins of fuel pump relay to enable the fuel pump relay

and fuel pump to operate. Examine and confirm whether the

fuel pressure is approx. 350 kPa.

Yes

Next step

No

13

10

Apply the special connecting terminal to directly supply the

fuel injector 12 V voltage from the battery, and examine the

normal operation of fuel injector.

Yes

12

No

Next step

11

Rinse the fuel injector, and then reexamine the normal

operation of fuel injector.

Yes

Next step

No

Replace the fuel

injector

12

Examine and confirm whether the fuel deteriorates or contains

water.

Yes

Replace fuel

No

18

13

Examine and confirm whether the fuel pressure is less than 350

Yes

Next step

Chery T11 Service Manual Electric Injection System

74

kPa.

No

17

14

Turn off the fuel gage valve, turn on the ignition switch again

to enable the fuel pump to operate again, and examine and

confirm whether the fuel pressure can be established.

Yes

Next step

No

16

15

Turn on the fuel gage valve, apply the fuel return immobiliser

to clip the fuel return pipe tightly so as to make it hasn’t fuel

return, and examine and confirm whether it is able to establish

the fuel pressure quickly.

Yes

Replace the fuel

pressure

regulator

No

Repair or

replace the fuel

injector or fuel

pipe

16

Examine the leakage or jamming of the fuel intake pipe.

Yes

Repair or

replace the fuel

intake pipe

No

Replace the fuel

pump

17

Examine the jamming or bending of the fuel return pipe

Yes

Repair or

replace the fuel

return pipe

No

Replace the fuel

pressure

regulator

18

Examine and confirm whether the sensing holes of intake

manifold pressure and intake temperature sensor are jammed.

Yes

Clean

No

Next step

19

Enable the engine to operate at idle speed, and, after the

coolant temperature reaches the closed-loop control activated

temperature, view whether the operation of oxygen sensor is

normal. (Fluctuate between 0V and 1V.)

Yes

Next step

No

Examine

oxygen sensor

and harness

20

Examine the leakage of engine intake system.

Yes

Remove the

leakage

No

Next step

21

Examine and confirm whether the cylinder pressure of engine

is normal.

Yes

Next step

No

Remove the

failure

22

Enable the engine to operate at idle speed, and, after the

coolant temperature reaches the normal value, examine and

confirm whether the ignition advance angle is normal.

Yes

Replace ECU

No

Examine the

others

Chery T11 Service Manual Electric Injection System

75

7) Unstable idle during warm up

No.

Operation Step

Detection

Result

Subsequent Step

1

Place the ignition switch on the “ON” position, and apply the

failure diagnosis instrument to examine and confirm whether

there are some failure information records.

Yes

Remove

the

displayed failure

No

Next step

2

Examine and confirm whether the air cleaner is unobstructed.

Yes

Next step

No

Replace

3

Enable the engine to operate at idle speed, and detect and

confirm whether the pressure of intake manifold during warm

up is between 35 kPa and 55 kPa.

Yes

Next step

No

Remove the intake

system leakage

failure

4

Switch off the engine, turn off the ignition switch, connect an

adaptor between the ECU and harness, and examine and

confirm whether the voltages of intake temperature sensor,

water temperature sensor and ECU’s No 4 and 20 pins (applied

for 4.5 to 5V sensor power supply) are normal.

Yes

Next step

No

Examine and

repair

5

Pull out the idle actuator connector on the harness before the

completion of warm up, and view whether the engine speed

changes (the engine enters the Fault Mode).

Yes

Next step

No

Replace the idle

actuator

6

Examine and confirm whether the coolant temperature sensor

operates normally.

Yes

Next step

No

Replace

7

Enable the engine to operate at idle speed, and, after the

coolant temperature reaches the normal value, examine and

confirm whether the ignition advance angle is normal.

Yes

Replace ECU

No

Examine the

others

Chery T11 Service Manual Electric Injection System

76

8) Unstable idle after the completion of warm up

No.

Operation Step

Detection

Result

Subsequent

Step

1

Place the ignition switch on the “ON” position, and apply the

failure diagnosis instrument to examine and confirm whether

there are some failure information records.

Yes

Remove

the

displayed

failure

No

Next step

2

Place the ignition switch on the “ON” position. Connect up an

adaptor between ECU and harness, and examine and confirm

whether the voltages of ECU’s intake manifold absolute pressure

sensor output, intake temperature sensor output, coolant

temperature sensor output, oxygen sensor output pins, and the

voltage of ECU’s (outputs to idle actuator) pins are normal.

Yes

Next step

No

Repair or

replace

harness and

its

corresponding

parts

3

Stop the engine, and examine and confirm whether the air cleaner

is unobstructed.

Yes

Next step

No

Replace

4

Detect and confirm whether the pressure of intake manifold

during idle operation is between 35 kPa and 55 kPa.

Yes

Next step

No

Remove the

intake system

leakage

failure

5

Connect the fuel pressure gage valve (the connecting point

changes as the vehicle model). Short circuit the No 30 and 87

pins of fuel pump relay to enable the fuel pump relay and fuel

pump to operate. Examine and confirm whether the fuel pressure

is approx. 350 kPa.

Yes

Next step

No

9

6

Apply the special connecting terminal to directly supply the fuel

injector 12 V voltage from the battery, and examine the normal

operation of fuel injector.

Yes

8

No

Next step

7

Rinse the fuel injector, and then reexamine the normal operation

of fuel injector.

Yes

Next step

No

Replace the

fuel injector

8

Examine and confirm whether the fuel deteriorates or contains

water.

Yes

Replace fuel

No

14

9

Examine and confirm whether the fuel pressure is less than 350

kPa.

Yes

Next step

No

13

10

Turn off the fuel gage valve, turn on the ignition switch again to

enable the fuel pump to operate again, and examine and confirm

whether the fuel pressure can be established.

Yes

Next step

No

12

11

Turn on the fuel gage valve, apply the fuel return immobiliser to

clip the fuel return pipe tightly so as to make it hasn’t fuel return,

and examine and confirm whether it is able to establish the fuel

Yes

Replace the

fuel pressure

regulator