Geely Emgrand X7. Manual part — 52

(a) Rotated ignition switch to OFF

position.

(b) Disconnect the rear oxygen

sensor wiring harness connector
EM03.

(c)

Disconnect ECM harness
connector EM01.

(d) Test Continuity between rear

oxygen sensor wiring harness
connector EM03 terminal C and
ECM harness connector EM01
terminal No.23.

ECM线束连接器

EM01

1

2

4

5

3

81

63

44

25

6

62

43

24 23 22 21 20 19 18 17 16 15 14 13 12 11 10

9

8

7

26

42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27

45

46

61 60 59 58 57 56 55 54 53 52 51 50 49 48 47

64

65

66

80 79 78 77 76 75 74 73 72 71 70 69 68 67

NL02-0033c

Standard Resistance: Less than 1 Ω

(e) Connect ECM harness connector EM01.

(f) Connect the rear oxygen sensor wiring harness connector EM03.

Is resistance the specified value?

(a) Inspect whether ECM power supply circuit is normal.

(b) Inspect whether ECM ground circuit is normal.

Step 6

Replace ECM. Refer to 2.2.8.1 Replacement of Engine Control Module.

(a) Replace

ECM.

(b) Carry out the crankshaft position sensor learning; refer to 2.2.7.11 “Crankshaft Position

Sensor (CKP) Learning.

Step 7

Use fault diagnosis tester to confirm if DTC is stored again .

(a) Connect the 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) test the vehicle on the road for at least 5min.

Step 5

Inspect ECM working circuit.

Yes

No

Repair the faulty part.

Yes

No

ECM control circuit malfunction.

Yes

ECMharness connectorEM01

207

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

Step 8

Troubleshooting

5. Maintenance

guide:

Refer to 2.4.6.1 “Replacement of Rear Oxygen Sensor” to replace the rear oxygen sensor.

No

Refer to 2.2.7.3 Intermittent Fault Inspection for
intermittent fault.

Yes

208

2.2.7.26 DTC P0171 P0172 P1167 P1171 P2187 P2188

1. DTC

description:

DTC P0171

Mixture Too Thin

DTC P0172

Mixture Too Thick

DTC P1167

Pre-catalytic Oxygen Indicating Mixture Too Thick During Deceleration

DTC P1171

Pre-Catalytic Oxygen Indicating Mixture Too Thin During Acceleration

DTC P2187

Mixture Too Thin When Idling

DTC P2188

Mixture Too Thick When Idling

Engine Control Module (ECM) controls the close-loop Air-fuel ratio Measure system that
achieves optimal combination of performance, fuel economy and emission control. In the
close-loop mode, the engine control module monitors heated oxygen sensor (HO2S) signal voltage
and adjusts fuel supply according to the signal. Changes in fuel supply will change the value of
long-term and short-term fuel supply adjustment. Short-term fuel supply adjustment will respond
to heated type oxygen sensor signal voltage and rapidly change. These changes will fine tune the
fuel supply. Long-term fuel supply adjustment will respond to the trend in shortterm fuel supply
adjustment. Long-term fuel adjustment adjusts the fuel supply in order to return to the center of
the short-term fuel adjustment value and controls the short-term fuel adjustment. The ideal fuel
adjustment value is around 0%. A positive value indicates that engine control module is increasing
fuel supply to compensate the lean Air-fuel mixture. A negative value indicates that engine control
module is decreasing fuel supply to compensate the thick Air-Fuel mixture.

2. Conditions for Setting DTC and the Fault Location:

DTC
Code

DTC Detection Strategy

Set(Control

Strategy)

Conditions

Fault Locations

P0171

P0172

P1167

P1171

P2187

P2188

1. Fuel

Adjustment

Value Higher Than
Maximum Limit

2. Fuel

Adjustment

Value Lower Than
Minimum Limit

3. Fuel

Adjustment

Value Higher Than
Maximum Limit
(Low-Load Zone)

4. Fuel

Adjustment

Value Lower Than

1. Engine slows down and

enters (DFCO) working
condition.

2. ECM detected oxygen

sensor signal voltage is
higher than 0.55 V.

3. Engine

enters

power-enriched (PE)
working condition.

4. ECM detected oxygen

sensor signal voltage is
lower than 0.35V.

1、 Fuel Injectors

2、 Canister

3、 MAP

4、 TPS

5、 HO2S（Front）

209

Minimum Limit
(Low-Load Zone)

5. Duration longer than 12s.

3. Circuit

figure

Refer to 2.2.6 Electrical Schematic Diagram.

4. Diagnostic

Steps:

Note: Before carrying out this diagnosis step, observe the data list on fault diagnosis tester and
analyze the accuracy of the data, as these will help with quick diagnosis.

Step 1

Inspect there are no other control system 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.

Are there DTC codes other than P0171, P0172, P1167, P1171, P2187, P2188?

Step 2

Read the intake manifold absolute pressure sensor data.

(a) Turn ignition switch to OFF position, connect fault diagnosis tester.

(b) Start vehicle .

(c) Read the intake manifold absolute pressure sensor data.

(d) Read the fault diagnosis tester for atmospheric pressure value, and compare it with table

2.2.1.3 Altitude and Atmospheric Pressure Correlation.

Is fault diagnosis tester atmospheric pressure reading normal?

Step 3

Read the throttle position sensor data stream.

(a) Start

the

vehicle.

(b) Warm up the engine with normal idle speed and throttle opening is less than 10%.

(c) Use fault diagnosis tester to read throttle position sensor data.

Is throttle position sensor data normal?

No

Refer to 2.2.7.21 DTC P0122 P0123

Yes

No

Refer to 2.2.7.18 DTC P0107 P0108

Yes

Yes

Refer to 2.3.6.7 DTC Code Section Index

No

210