2.10.5 Electrical schematic diagram 

2.10.5.1 Electrical schematic diagram 

曲轴位置传感器

发动机控制模块

ECM

凸轮轴位置传感器

1缸点火线圈

2缸点火线圈

3缸点火线圈

4缸点火线圈

爆震传感器

NL02-0067c

 

 

蓄电池

EF40

EF21

主继电器ER09

87

30

86

85

4

EM01 COILA

EM01 MPR

1

EM01 COILB

81

44

EM01 COILD

62

EM01 COILC

发

动

机
控

制

模

块

一缸点火线圈

3

1

2

二缸点火线圈

3

1

2

三缸点火线圈

3

1

2

四缸点火线圈

3

1

2

NL02-0049c

 

 

Crankshaft position sensor 

Camshaft position sensor 

Knock sensor 

Engine control module

1st cylinderignition coil 

2nd cylinderignition coil 

3rd cylinderignition coil 

4th cylinderignition coil 

Main relay ER09 

Battery 

One cylinder ignition coil

Two cylindersignition 

coil

Three cylindersignition coil

Four cylinderignition 

coil

Engi

ne

 

contro

l

 modu

le 

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2.10.6 Diagnostic information and procedures 

2.10.6.1 Diagnosis descriptions 

Refer to 2.10.2.1 Description and Operation, get familiar with the system functions and operation 
before starting system diagnosis, so that it will help to determine the correct diagnostic steps, more 
importantly, it will also help to determine whether the situation described by the customer is 
normal. 

Refer to 2.11.5.1 Diagnosis Description and 2.11.5.2 Diagnosis Description”for the DTC Codes of 
the ignition system. 

2.10.6.2 Visual inspection 

z  Inspect the after-service retrofitting device that may affect the performance of the ignition 

system. 

z  Check the system components that is easy to access to identify whether there is significant 
damage or potential faults. 

2.10.6.3 Spark Plug Inspection and Diagnostic

 

A

B

C

D

GC02-0261b

 

1 

Refer to 2.10.7.4 “Replacement of Spark Plug” to dismantle the spark plug. 

 

2 

Inspect whether the terminal binding post A is bent or cracked. Test the loose of the 
terminal A via twisting or pulling. 

 

3 

Inspect whether the B-insulator has arcing or signs of leakage, which is due to 
discharging between the two ends of terminal B which lies between terminal A and the 

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grounding point. 

Inspect whether there are following conditions: 

A.  Inspect the high-voltage damping line for damage. 

B.  Inspect whether the cylinder hood spark plug groove is wet. Whether there is engine oil, 

engine coolant or water. Damped spark plug will cause arc discharge. 

 

4 

Inspect whether there is crack on the insulator B, otherwise it will cause discharging. 

 

A.  Inspect whether the spark plug torque is normal. The tightening torque of the spark plug is 

20-30N.m (14.8-22.2lb-ft). If the torque is insufficient, the spark plug will not work normally. 
Too large tightening torque of the spark plug may lead to the fracture of the insulator B. 

B.  Inspect for signs of leakage around the insulator tip rather than near the center electrode D. 

C.  Inspect for the electrode C-side fracture and worn. 

D.  Inspect the center electrode D fracture, worn or loosen via shaking the spark plug. If there is 

click sound, the internal part is broken. The loosen center electrode D will decrease the 
intensity of the spark. 

E.  Inspect whether electrodes C and D are shorted. If it is the case, the residue on the electrode 

C will reduce or even the gap will disappear. 

F.  Inspect whether the electrode is too dirty. 

 

6 

Inspect the cylinder hood slot for debris, otherwise it may damage the spark plug 
during installation. 

 

5 

Inspect for the abnormal discharge signs of the center electrode C. Measure the 
clearance between the center electrodes. 

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2.10.6.4 Common Spark Plug Malfunction 

Serious Spark Plug Burn: Spark plug top scars, damage or electrode melting, brunt all indicate that 
the spark plug has been damaged and should be replaced. Inspect the symptoms as well as color 
changes when replacing the spark plug, in order to analyze the reasons for malfunction. Refer to 
2.10.7.4 “Replacement of Spark plug” 

1.  Electrode melting and the insulator turning white indicate that combustion chamber 

temperature is too high. This may be due to there is too much carbon residue in the 
combustion chamber, so that valve clearance is too small caused by overheating or cooling 
malfunction. Another possible reason is that the tightening torque of spark plug does not 
match the specified value. 

2.  Electrode becomes rounded and the insulator has a scar, indicating that an early engine 

combustion. It may be due to premature ignition timing, low-octane gasoline or spark plug is 
too hot. 

3.  Insulator top is broken. Knock combustion is the main reason for the insulator rupture. 

Premature ignition timing, low-octane gasoline or spark plug too hot may lead to engine 
knocking. 

4.  Insulator top has cinereous strips. Such strips indicate the leakage of the spark plug and it is 

necessary to replace a new one. 

Spark Plug Residue: There is residue between the spark plug insulator top and the electrodes. In 
severe cases, it can cause the engine inoperation. Cleaning the spark plug can be a temporary 
solution. In order to maintain good performance, identify the root cause for the malfunction. 

1.  Oily Residue. Spark plug has oily residues, indicating that lubrication oil enters the 

combustion chamber. If it only happens to an individual spark plug, the valve rod seals may 
be damaged. If every cylinder spark plug has oily residue, it indicates that there is cylinder 
channeling oil. Inspect whether the air filter and ventilation device is blocked. 

2.  Black Residue. There is black residue on the spark plug electrodes and inside the spark plug, 

indicating that the mixture is too thick. Increase the engine running speed and continue for a 
few minutes to burn the layer of black soot on the electrode. 

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