Geely Emgrand X7. Manual part — 73

2.2.7.46 DTC P0641 P0651

1. DTC

description:

DTC P0641 ETC Reference Voltage A # Amplitude Fault

DTC P0651 ETC Reference Voltage B # Amplitude Fault

As ETC uses two throttle position sensors, its normal working required 5 V reference voltage and
low reference voltage is shared with ETC harness connector terminals A and D. Where A and
EM01 terminal No.74 is connected as the low reference voltage. Terminal D and EM01 terminal
No.70 is connected as the 5 V reference voltage. Malfunction in any circuit will report DTC code
P0641 or P0651.

2. Conditions For Setting DTC and The Fault Location:

DTC
Code

DTC Detection
Strategy

Conditions For Setting The DTC
(Control Strategy)

Fault Locations

P0641

P0651

Hardware Circuit
Malfunction

Internal chip self-diagnosis

1. Electronic

Throttle

Body

2. Electronic

Throttle

Circuit

3. ECM

3. Circuit

sketch

Refer to 2.2.7.21 DTC P0122 P0123

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.

1

Inspect ETC harness connector EM28 terminals A and D.

A. rotated ignition switch to OFF

position .

B.

Disconnect ETC harness
connector EM28.

C. Rotated ignition switch to ON

position .

D. Measure resistance between

EM28 terminal A and a reliable
ground.

E. Measure voltage between EM28

terminal D and a reliable ground.

电子节气门线束连接器

EM28

A

E

B

F

C

G

D

H

NL02-0029c

Results

Test Items

Standard Value

Electric throttle harness connectorEM28

291

Resistance Between EM28 (A) and a Reliable
Ground

Less than 3 Ω

Voltage BetweenEM28 (D) and A Reliable
Ground

4 . 8 - 5. 2 V

Does it conform to the standard value?

2

Replace the electronic throttle body

Refer to the Replacement of Electronic Throttle Body.

3

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

A. Connect fault diagnosis tester to the data link connector.

B. Rotated 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 10min.

F. Read control system DTC code again to confirm that the system has no DTC code output.

4

Inspect ECM Power Supply Circuit and ground circuit.

A. Refer to 2.2.7.43 DTC P0562 P0563 to inspect ECM Power Supply Circuit and ground

circuit.

ECM power and ground circuits normal?

5

Replace ECM. Refer to 2.2.8.6 Replacement of Engine Control Module.

6

Carry out the crankshaft position sensor learning, refer to 2.2.7.11 “Crankshaft
Position Sensor (CKP) Learning.

Refer to 2.2.7.11 "Crankshaft Position Sensor Learn".

Next

No

Power and ground circuits fault.

Yes

No

Refer to 2.2.7.3 Intermittent Fault
Inspection for intermittent fault.

Yes

Next

No

Circuit malfunction, repair circuit.

Yes

292

7

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

A. Connect fault diagnosis tester to the data link connector.

B. Rotated 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 10min.

F. Read control system DTC code again to confirm that the system has no DTC code output.

8 Troubleshooting

No

Refer to 2.3.7.3 Intermittent Fault
Inspection for intermittent fault.

Yes

Next

293

2.2.7.47 DTC P0646, P0647

1. DTC

description:

DTC P0646

Air-conditioning Clutch Relay Circuit Short to Low Voltage or Open

DTC P0647

Air-conditioning Clutch Relay Circuit Short to High Voltage

The working voltage of the air-conditioning compressor relay is provided by the main relay which
is controlled by ECM. ECM controls Air-Conditioning compressor relay internal ground through
ECM harness connector EM01 terminal No.9, and relay pulls in. ECM has an internal driver
circuit that controls relay coil ground. The driver circuit is equipped with a feedback circuit to
ECM. ECM monitors the feedback voltage control circuit to determine whether the there is an
open circuit, a circuit short to ground or power supply.

2. Conditions For Setting DTC and The Fault Location:

DTC Code

DTC Detection
Strategy

Conditions For Setting The
DTC (Control Strategy)

Fault Locations

P0646

When air-conditioning is not
working, with air-conditioning
relay control circuit open or
short to ground, the DTC code
will be set.

P0647

Hardware Circuit
Inspection

When air-conditioning is not
working, with air-conditioning
relay control circuit open or
short to ground, the DTC code
will be set.

1. Air Conditioner Relay

2. ECM

3. Air-Conditioning

Relay

Circuit

3. Circuit figure :

Refer to 8.2.6.2 Air-conditioning System Circuit Diagram

4. Diagnostic

Steps:

Refer to 8.2.7.8 Air-conditioning Clutch Inoperation.

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