Chery A15. Manual - part 157

  Chery A15 Maintenance Manual 

to avoid mistrigger of airbag. The safety sensor equipped to Chery A15 is composed 

of a dual contactor and a motor switch. 

The safety sensor is independent of electronic components when working. Airbag 

ignition circuit is in “standby” status under normal running of vehicle and will be 

activated when the inflation of airbag is necessary (above 6.4 acceleration of gravity). 

3. Hairspring 

A spiral wire harness is used to be placed between steering wheel and steering post to 

ensure sufficient turning angle and avoid damaging connecting wire harness of airbag 

subassembly. First fit the wire harness in helical spring, and then fix the helical spring 

in spring housing. This subassembly is called hairspring. Generally horn wire harness 

is also fitted in the helical spring. 

 

 

 

 

 

 

 

Spec. 

Outer diameter: Φ96m 

Number of coils: Max. 6 

Storage temperature: -40ºC～85ºC 

Working temperature: -35ºC～85ºC 

Working voltage: DC 9～16V 

Working current (airbag configuration): Max. 16A, 40V－6ms 

Current limit: Max. 5 seconds with 5A current 

Voltage limit: Max. 100ms with DC 20V 

Working torque: Max. 0.15ms 

 

Hairspring 

  Chery A15 Maintenance Manual 

Fixed on steering post. 

Part of horn circuit. 

Note: turning steering wheel for more than 4.5 turns will damage hairspring. 

Turing steering wheel: 

Turning steering wheel to one side tightens coil. 

Turning steering wheel to another side releases coil. 

Turning steering wheel for more than 4.5 turns will damage hairspring. 

(Total turning range: 9 turns) 

 

 

 

 

 

 

 

Warning: demounting hairspring will cause injury and car damage, therefore never 

demount hairspring. If the airbag has been inflated, replace the hairspring. Please 

demount airbag subassembly, hairspring and safety memory device before 

maintenance of steering system. Before demounting or mounting airbag subassembly, 

please disconnect battery cathode and wait for at least 1 minute. 

Demounting/Mounting Hairspring 

Hairspring is mounted between steering wheel and steering post. When demounting, 

pay attention to mounting position and direction to avoid insufficient turning angle of 

steering wheel or heavy steering. 

It is necessary to check hairspring clearance during steering before demounting or 

mounting hairspring. 

Warning: to check clearance, carefully turn hairspring until resistance is felt, and then 

turn back for about 4 turns and align with clearance mark. 

 

 

  Chery A15 Maintenance Manual 

 

 

 

Turing mark 

Fixed mark 

 

 

 

      Mounting 

hairspring 

 

4. Airbag Subassembly 

(1) Airbag Subassembly 

Airbag subassembly mainly consists of airbag cover, airbag, inflator subassembly. 

Airbag is made of nylon fabric with chemical glue applied on inner layer to seal air 

inside. Unused airbag is folded like a packed parachute between gas generator and 

airbag cover. A tearing line is stamped on airbag cover to help inflated airbag tear 

cover and reduce inflating resistance. 

Generally the inflation will begin within 10ms after vehicle collision, and the total 

inflating time is about 30ms. Airbag will spread along steering post with a sight 

deflection toward windshield to prevent collisions of driver’s face with windshield 

and the chest with steering wheel. 

Vent holes are set on the backside of airbag (opposite to driver). When the diver hits 

airbag due to inertia force, the air inside will be vented by the pressure to absorb the 

kinetic energy from driver and protect driver’s body against injuries. 

Inflator subassembly works to inflate airbag when ignitor is lighted to spread the 

airbag. When computer sends command ignition signal, heating cord is switched on 

and heated rapidly to ignite ignitor, which immediately will explode to generate heat 

to make inflating agent release air to be inflated into airbag. 

 

 

 

 

  Chery A15 Maintenance Manual 

Inflator assembly

Assembly base 

Bolts 

Tightening torque

 

Fixing ring assembly

Bumper pad

Cover

 

 

 

 

 

 

 

 

 

 

 

 

(2). BCM (Airbag Control Module) 

An unrepairable component part which monitors other system component parts and 

sends command to activate airbag. 

Records any detected fault. 

Turns on warning light to remind driver of fault. 

Only to be diagnosed against code with diagnoser. 

BCM controls the inflation and spread of airbag through following component parts: 

.  Safety sensor 

.  Capacitor 

.  Collision sensor or accelerometer. 

(3). Capacitor 

The capacitor provides power reserve. 

(4). Bulb 

Once the working voltage reaches BCM point, the warning light will be turned on, at 

this moment we can check the bulb. BCM controls the light to keep on for about 4 

seconds and then go out during the bulb check. 

Fault Display 

BCM records system faults in two modes.