Geely Emgrand X7. Manual part — 58

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

(b) Turn ignition switch to ON position.

(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.

Step 10

Troubleshooting

5. Maintenance

guide

:

Refer to 2.2.8.5 “Replacement of Fuel Injectors” to replace the fuel injectors.

No

Refer to 2.2.7.3 Intermittent Fault
Inspection for intermittent fault.

Yes

231

2.2.7.32 DTC P0270 P0271

1. DTC

description:

DTC P0270

Cylinder No.4 fuel injector circuit low voltage fault

DTC P0271

Cylinder No.4 fuel injector circuit high voltage fault

Fuel injectors operating voltage is provided by The Main Relay controlled by ECM. Battery
voltage passes through the main relay terminal No.3 to all fuel injector wiring harness connectors
terminal No.A. ECM controls Cylinder No.4 fuel injector internal ground circuit through ECM
harness connector EM01 terminal No.26. ECM monitors all fuel injector driver circuits status, if
ECM detects driving circuit status corresponding voltage is incorrect, ECM will set a fuel injector
control circuit fault DTC code.

2. Conditions For Setting DTC and The Fault Location:

DTC Code

DTC Detection
Strategy

Conditions For Setting
The DTC (Control
Strategy)

Fault Locations

P0270

Hardware Circuit
Inspection

Injector Signal Circuit
Open or Short To Ground

P0271

Hardware Circuit
Inspection

Injector Signal Circuit
Short To Power Supply

1. Sensor

Circuit

2. Sensor

3. ECM.

3. Circuit

sketch

主继电器ER09

87

30

86

85

EM01

44

EM01

B

A

发

动
机

控

制

模
块

蓄电池

EF4

0

EF22

1缸喷油器

3缸喷油器

4缸喷油器

2缸喷油器

6

MPR

INJA

EM01

B

A

7

INJB

EM01

B

A

25

INJC

EM01

B

A

8

INJD

NL02-0043c

4. Diagnostic

Steps:

Note: Before carrying out this diagnosis step, observe the data list on fault diagnosis tester and

Main relay ER09

Battery

1st cyinder

oil injecter

3rd cyinder

oil injecter

4th cyinder

oil injecter

2nd cyinder

oil injecter

Engi

ne

co

ntr

ol mo

dul

e

232

analyze the accuracy of the data, as these will help with quick diagnosis.

Step 1

Initial Inspection

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

loosening

Step 2

Measure the fuel injector resistance.

(a) Disconnect the fuel injector

wiring harness connector EM17.

(b) Measure resistance between the

two fuel injector terminals.

Standard Resistance

11.5-12.4Ω @ 20 (68 )

℃

℉

(c) Connect the fuel injector harness

connector EM17.

喷油器4线束连接器 EM17

B

A

NL02-0048c

(a) Rotated ignition switch to OFF position .

(b) Disconnect cylinder No.4 fuel injector wiring harness connector EM17.

(c) Rotated ignition switch to ON position .

(d) Measure voltage between cylinder No.4 fuel injector wiring harness connector EM17 No.A

terminal and a reliable ground.

Standard Voltage: 11-14V

(e) Connect cylinder No.4 fuel injector wiring harness connector EM17.

(a) Rotated ignition switch to OFF position .

(b) Disconnect cylinder No.4 fuel injector wiring harness connector EM17.

3

Measure Fuel Injectors Working power supply

Step 4

Inspect the fuel injector control circuit.

No

Go to step 5

Yes

No

Refer to 2.2.8.2 “Replacement of Fuel
Injectors” to replace the fuel injectors

Yes

Next

Oil injecter 4harness connectorEM17

233

(c) Connect a light-emitting diodes test lamp to the fuel injector wiring harness connector EM17

terminal No.A and B.

(d) Start

the

engine.

(e) Observe whether test lamp is flashing.

Is test lamp flashing as normal?

Step 5

Inspect and repair cylinder No.4 fuel injector power circuit.

(a) Rotated ignition switch to OFF

position .

(b) Disconnect the fuel injector

wiring harness connector EM17.

(c) Dismantle the engine main relay.

(d)

Measure resistance between
cylinder No.4 fuel injector wiring
harness connector EM17 terminal
No.B and engine main relay
terminal No.30.

(e)

Measure resistance between
cylinder No.2 fuel injector wiring
harness connector EM17 terminal
No.B and a reliable ground.

ER03

85

86

87

30

30

87

86

85

ER05

30

87

86

85

ER06

30

87

87a

86

85

ER11

ER08

ER

09

85

86

87

30

ER10

2

1

5

3

2

1

5

3

2

1

5

3

ER04

ER02

2

1

5

3

2

1

5

3

ER01

ER07

2

1

5

3

1

2

3

4

11

12

13

14

15

16

5

6

7

8

9

10

EF

0

8

EF

0

7

EF

2

7

EF

2

6

EF

2

2

EF

2

9

EF

0

3

EF

0

6

EF

0

9

EF

2

5

EF

1

7

EF

1

6

EF

1

5

EF

3

5

EF

2

1

EF1

4

EF

01

EF

02

EF

04

EF

10

EF

1

1

EF1

8

EF2

4

NL02-0045c

Standard Resistance

Test Items

Standard Value

Resistance Between EM17 (B) and Main Relay Terminal No.30

Less than 1 Ω

Resistance Between EM17 (B) and A Reliable Ground

10 kΩ or higher

(f) Install the engine main relay.

(g) Connect cylinder No.4 fuel injector harness connector EM17.

Exclude the fuel injector power supply circuit fault.

Step 6

Inspect the Cylinder #4 fuel injector control circuit.

Go to step 6

Go to step 7

No

Yes

Go to step 9

Next

234