Geely Emgrand X7. Manual part — 204

(c) Clear DTC code.

(d) Start and run the engine at idle speed to warm up the engine for at least 5 min.

(e) Road test the vehicle for at least 10 min.

(f) Read control system DTC code again to confirm that the system has no DTC code.

5. Maintenance

guide:

Refer to 2.12.8.5 “Replacement of Fuel Injectors” to replace the fuel injectors.

Step 10

Troubleshooting

No

Refer to 2.12.7.3 Intermittent Fault
Inspection for intermittent fault.

Yes

815

2.12.7.33 DTC P0300

1. DTC

description:

DTC P0300

Multi-Cylinder Misfire

The engine control module (ECM) uses information from the crankshaft position (CKP) sensor
and the camshaft position (CMP) sensors to determine when an engine mis?re is occurring. By
monitoring variations in the crankshaft rotation speed for each cylinder ECM is able to detect
individual mis?re events. When a misfire happens, unburnt mixture will be discharged into the
exhaust system and burnt in the 3-way catalytic converter (TWC) which will overheat the
converter. A misfire rate that is high enough can cause 3-way catalytic converter damage. The
malfunction indicator lamp (MIL) will ash ON and OFF when the conditions for catalytic
converter overheated are present. A DTC will be set.

2. Setting DTC code and Fault Location:

DTC Code

DTC Detection
Strategy

Conditions For Setting The
DTC (Control Strategy)

Fault Locations

P0300

Under stable
operating
conditions, ECM
detects the
crankshaft
rotation speed
fluctuations.

Under stable operating
conditions, When the ECM
detects the crankshaft rotation
speed fluctuations exceeding the
threshold set by the system:
When the fire degree is too low
for affecting the exhaust
emission, without emergency
control scheme, only record the
fault code and freeze the data
stream as well as turn on the
fault indication.

Lamp; when the fire degree is
too high, which may lead to
overheating of the catalyst,
compel to entering the fuel
open-loop control working
condition, and inhibit oxygen
correction learning. The fault
indicator lamp flickers with the
frequency of 1HZ.

1. Connector Loose or

Poor Connection

2. Vacuum Tube Hose

Broken or Loose

3. Ignition

System

4. Fuel

Injectors

5. Fuel

Pressure

6. Intake Air Pressure

Sensor

7. Engine

Coolant

Temperature Sensor

8. Cylinder

Compression

Pressure

9. Valve Clearance and

Timing

10. Evaporative Emission

Control System

11. Purged

Crankcase

Ventilation System

12. Intake System

13. Poor Exhaust System

Ventilation

14. ECM.

816

3. Circuit

sketch

Ignition System

NL02-2098b

ECM

44

EN01

BAT

20A

E

F

22

MPR

86

87

30

85

发动机主继电器

4

EN01

1

EN01

A EN20

B EN20

C EN20

点火线圈

COILA

COILB

Fuel Injector Nozzle

NL02-2099b

6

EN01

A

EN11

B

EN11

1缸燃油喷射器

ECM

INJA

8

EN01

A

EN12

B

EN12

2缸燃油喷射器

INJD

7

EN01

A

EN13

B

EN13

3缸燃油喷射器

INJB

25

EN01

A

EN14

B

EN14

4缸燃油喷射器

INJC

44

EN01

BAT

15

A

E

F2

1

MPR

86

87

30

85

发动机主继电器

2. Diagnostic

Steps:

Notes:

– If the control system stores DTC other than misfire, diagnose these DTC first and

eliminate the faults.

Engine Main
relay

Ignition coil

Engine main
relay

1st cylinderfuel injector

2nd cylinderfuel injector

3rd cylinderfuel injector

4th cylinderfuel injector

817

–

If the vehicle does not have a misfire when sent to a service station, road test the vehicle, so
that the misfire will occur again. Use fault diagnosis tester to record ECM data when
misfire is occurring, in order to facilitate analyzing the cause of the fault.

–

If after a long period road test, ECM does not store any misfire associated DTC codes, then
the fault may be due to the following reasons:

•

Overfill fuel tank and fuel enters the evaporative emission control system, so that the
mixture is too thick and causes misfire.

•

Use improper fuel caused poor combustion and misfire.

•

Contaminated spark plug causes the ignition failure and misfire.

•

Carry out basic inspections at fault locations identified by DTC codes.

–

Road test the vehicle after repair to confirm no DTC is stored.

Step 1

Initial Inspection

(a) Inspect the harness connector for damage, poor connection, aging or signs of loosening.

(b) Inspect the vacuum tube for damaged, loose, leakage and so on.

Step 2

Inspect other DTC codes output.

(a) Connect fault diagnosis tester to the vehicle diagnostic interface.

(b) Turn ignition switch to ON position.

(c) Press the fault diagnosis tester power button.

(d) Select the following menu items: Engine/Read DTC codes.

(e) Read DTC codes.

Results

DTC Codes Shown

GO to Step

DTC codes other than P0300

No

DTCP0300 Yes

Step 3

Inspect the vacuum tube and the air intake system.

(a) Inspect vacuum canister solenoid valve connection is correct or not and leakage.

(b) Inspect the vacuum brake booster vacuum tube connection is correct or not and leakage.

(c) Inspect the intake tube pressure sensor connection is correct or not and leakage.

No

Refer to 2.12.7.14 DTC Chapter Index.

Yes

Next

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