Chery A15. Manual - part 124

 

safety memory unit before handling with the steering system. In order to 
remove or install the airbag components, please disconnect the negative grid 
of the battery and wait for at least 1 minute. 

Removal/Installation 

The hairspring is installed between the steering wheel and the steering column. When 
installing the hairspring, pay attention to the installing position and direction, otherwise it 
would cause insufficient turning angle or heavy rotation of the steering wheel. 

In order to remove and install the hairspring, it is necessary to check the hairspring clearance 
during rotating. 

Warning: In order to check the clearance, turn the hairspring carefully until we can feel the 
resistance. After that turn back for about 4 cycles and align it with the clearance marking. 

 

 
 
 
 
 
 
 
 
 
 
 

 

                                       

Scheme of the hairspring installation   

4. AIRBAG COMPONENTS 

(1) Airbag components 

The airbag components consist of the airbag decoration cover, airbag and inflating 
components. The airbag is made of nylon fabric. The internal layer was treated with synthetic 
glue for sealing air. When the airbag is not open, it is folded like a bag of the unopened 
parachute and installed between the upper part of air inflator and the airbag cover. There is a 
impression line for tearing on the surface of the airbag decoration cover so that the decoration 
cover can be torn off easily during the inflation of the airbag and reduce its resistance to let 
the airbag passes through. 

When the vehicle is collided, normally the airbag will start to inflate within 10ms after the 
first collision, and the total inflation time from the starting of inflation through the entirely 
activation of the airbag is about 30mS. When the airbag is activated, it spreads out along the 
steering column to the direction of the windshield and thus prevents the driver’s face to 
collide with the windshield, and his chest to collide with the steering wheel. 

There is an air discharging hole at the back of airbag (opposite to the driver). When the driver 

Fastening 
mark 

Turning mark 

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presses on the airbag due to the effect of inertia, the airbag is pressed and the air will be 
discharged from the discharging hole, so that the kinetic energy resulted by the collision 
between the driver and the airbag can be absorbed, which preventing the driver from injuring. 

The function of the inflator components is such that when the igniter activates the ignition 
agent, generating air and inflating the airbag, causing the airbag to spread out. When the 
computer sends the ignition instruction, the heating element circuit turns on, which is heated 
quickly and activates the ignition agent, the activated ignition agent explodes immediately 
and generates heat, and then the inflating agent is heated up and decomposed to generate the 
air into the airbag. 

 

lid 

inflation assembly

machine base 
2 bolts 
tightening torque

fastening ring assembly 

preheat

 
 
 
 
 
 
 

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 

(2) BCM (airbag control module) 

Irreparable component. It is the component of the monitoring system during operation and 
sends the instructions when the airbag function. 

Record any detected malfunction. 

Turn on the warning lamp to warn the driver that there is a malfunction. 

Diagnose malfunction code can only be detected by the diagnostic tester. 

The BCM controls the inflation and spreading of the airbag through the following 

 

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components: 

·

Safety sensor 

·

Capacitor 

·

Collision sensor or accelerometer 

(4) Capacitor 

The capacitor provides the backup power. 

(5) Bulb 

When the operation voltage is increased to the BCM point, the BCM will trigger the warning 
lamp and we can now check the bulb. The BCM turns on the warning lamp for 4 seconds and 
then turn it off during the bulb inspection. 

Malfunction Display 

The airbag control module records the malfunctions of the system in two forms. 

1. Current malfunction. 

2. Historic malfunction detected before. 

(6) Warning lamp 

·

When any malfunction appears, the malfunction warning lamp will be turned on. 

·

It is kept “on”. 

(7) Wiring harness 

Most of the wiring harness linkers adopted in the airbag system are yellow. 

 

FAULT DIAGOSIS, INSPECTION AND OPERATION 

1. INSPECTION OF SRS DIAGNOSIS SYSTEM 

When the supplementary restriction system (SRS) is turned on, the airbag controlling module 
(BCM) will turn on the airbag warning lamp and start system self-diagnosis. The warning 
lamp will flash for 6 seconds with frequency of 1Hz during the system diagnosis. If BCM 
diagnoses any malfunction, it will turn on the airbag warning lamp and record the 
malfunction into the BCM memory. The BCM will diagnose the SRS system malfunction 
automatically once it is turned on. 

If 5 consecutive malfunctions are diagnosed during the self-checking, the SDM will mark the 
malfunction. A malfunction diagnosis test cycle is 400 milliseconds, so that the SDM will 
confirm the malfunction within 2 seconds (400 milliseconds x 5 times). If the malfunction is 
marked and maintained as the malfunction state, the warning lamp will be “ON” continuously. 
This state is called the “existing malfunction”. Once the malfunction is marked, and if this 
malfunction does not appear again after 25 continuous fault diagnosis test cycles (400 

 

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milliseconds X25=10 second), the malfunction mark will be cancelled. The warning lamp 
will be turned off under this condition, and it is called the “historical malfunction”. 

2. DIAGNOSIS OF THE DIAGOSTIC TESTER 

The diagnostic tester can read data from the BCM memorizer to carry on the continuous data 
exchanging. The diagnostic tester is used for reading and storing the malfunction codes, and 
clears part of the stored data after the maintenance. But it can not clear the interior 
malfunctions, such as the accident records and the arithmetic data malfunctions. 

The proper usage of the diagnostic tester: firstly, turn off the ignition switch, connect the 
diagnostic tester to the OBDII connector, and then turn on the ignition switch. See the 
diagnostic tester manual for the follow-up procedure.

 

 
SRS SYSTEM MAINTENANCE AND OPERATION 

If it is required to inspect the vehicle protection supplementary system or inspect the accident 
vehicle, the procedures below should be followed. If any malfunction is found, the 
corresponding parts should be replaced by new ones. 

1. MAINTENANCE OF SRS SYSTEM 

Warning: When the ignition is turned off and at the same time the fuse is taken out, the sensor 
and the diagnostic module (BCM) can provide the sufficient voltage for 1 minute to activate 
the airbag. If the airbag is not disconnected, then do not start the maintenance work within 1 
minute after turning off the power supply to BCM. If the airbag has been disconnected, then 
the maintenance work can be carried out immediately without waiting for the 1 minute 
electrical discharging time. The failure of shutting off the SRS system temporarily during the 
maintenance will result in false ignition, physical injury and SRS system discarded. 

(1) Turn off the airbag system 

Adjust the steering wheel to the center position, turn the ignition switch to “Lock” position 
and remove the key, remove the airbag fuse from the fuse box and wait for more than 1 
minute for BCM capacitor discharging. 

(2) Turn on the airbag system 

Insert the airbag fuse into fuse box, turn the ignition switch to “ON” position, and inspect 
whether the airbag indicator lamp is off after being on for 6 seconds. If the indicator lamp 
does not function in this way, please refer to the “Diagnosis and inspection of SRS system” of 
this manual. 

Warning: When the ignition switch is turned on, keep away from the airbag as far as possible, 
otherwise it may cause physical injury. 

(3) Operation, installation and diagnosis 

The airbag should be placed in an environment with the temperature not higher than 
65℃(149℉). If the airbag drop from a height of more than 0.9 meter (3 feet), the airbag and 

 

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