Malfunction display of SRS could confirm originally by the flash of indicating light, detailed information
could be gained by malfunction diagnostic tool.
a. Safety airbag indicating light is driven by ECU, all malfunction displays are finished by ECU. After

working voltage is supplied for safety airbag controller (KD4.1) by battery, safety airbag controller
(KD4.1) illuminates indicating light to check SRS. To notify driver that there are some malfunctions
in system, indicating light will illuminate for long time after working voltage is supplied. If existing
SRS does not have any malfunction, indicating light will close after illuminating for five seconds
after ignition on. In original phase, safety airbag controller (KD4.1) does not prepare to check the
impact and stop the unfold until the wire of safety airbag controller (KD4.1) is reliable.
After ignition switch is turned to “ON” gear, the display type of indicating light when there is no any
malfunction in SRS is:

Assembling malfunction information of subassembly could see follow table 1.

Table1: Assembling malfunction information indicating table for airbag subassembly

Schematic drawing for slow flash indicating light

Supplemental restraint system--Malfunction treatment

 245 

Ignition switch “ON”

Illuminate

Extinguish

Number

Malfunction type

Slow flash times (N times)

Remark

1

Igniter at the side of driver happens short circuit

3

2

Igniter  at the side of driver happens open circuit

4

3

Igniter at the side of driver connects grounding

5

4

Igniter  at the side of driver connects battery

6

5

Igniter

 

at the side of passenger happens short circuit

7

6

Igniter

 

at the side of passenger happens open circuit

8

7

Igniter

 

at the side of passenger connects grounding

9

8

Igniter at the side of passenger connects battery

10

9

Safety belt at the side of driver happens pre-tightening malfunction

11

10

Safety belt at the side of passenger happens pre-tightening malfunction

12

12

Impact output interface happens malfunction

or wrong explosion

of airbag subas-

sembly will make

big hurt for human,

i t s   w a r n i n g   r e a -

sons should be di-

vided detailedly.

Inner malfunction information could see following table 2.

Table 2: ECU inner malfunction information indicating table

Schematic drawing for fast flash indicating light

Schematic drawing for “short, short, long and short” malfunction

If happening the situations above, it is necessary to turn off key switch of automobile at first, then turn on key

switch and start it again, if information hint could not be removed, it is necessary to change ECU.

Supplemental restraint system--Malfunction treatment

 246 

Number

Malfunction type

Fast flash type

Remark

1

Electronic acceleration offset  malfunction

Short, short, short and long

0001

2

Electronic acceleration self-checking  malfunction

Short, short, long and short

0010

3

SCM inner RAM is wrong

Short, short, long and long

0011

4

Inner parameter is wrong

Short, long, short and short

0100

5

Inner malfunction or acceleration storage space is full and ignition record has been made. Short, long, short and long

0101

6

Mechanical safety sensor happens malfunction

Short, long, long and short

0110

7

Increased pressure is wrong

Short, long, long and long

0111

8

Ignition driving function is wrong

Long, short, short and short

1000

9

Voltage of ignition voltage F12 and F13 is wrong

Long, short, short and long

1001

10

Other parts are wrong

Long, short, long and short

1010

Supplemental restraint system--Repair

Repair

a. In using process, if happening any malfunction of power supply, it shows the voltage of power supply

is less than 9V or higher than 18V, or the battery is damaged, at this time, it only needs to charge or
change the battery.

b. Use special malfunction diagnostic tool to test.

Malfunction codes approved by safety airbag controller (KD4.1)

Number

Malfunction specification

Remove

1

Ignition circuit 1 (safety airbag at the side of driver), the resistance is too high or open circuit.

OK

2

Ignition circuit 1 (safety airbag at the side of driver), the resistance is too low or short circuit.

OK

3

Ignition circuit 1 (safety airbag at the side of driver), connects with the grounding

OK

4

Ignition circuit 1 (safety airbag at the side of driver), connects with power supply

OK

5

Ignition circuit 2 (safety airbag at the side of passenger), the resistance is too high or open circuit.

OK

6

Ignition circuit 2 (safety airbag at the side of passenger), the resistance is too low or short circuit.

OK

7

Ignition circuit 2 (safety airbag at the side of passenger), connects with the grounding

OK

8

Ignition circuit 2 (safety airbag at the side of passenger), connects with power supply.

OK

9

Ignition circuit 3 (pre-tension safety belt at the side of driver), the resistance is too high or open circuit.

OK

10

Ignition circuit 3 (pre-tension safety belt at the side of driver), the resistance is too low or short circuit.

OK

11

Ignition circuit 3 (pre-tension safety belt at the side of driver), connects with the grounding

OK

12

Ignition circuit 3 (pre-tension safety belt at the side of driver), connects with the power supply

OK

13

Ignition circuit 4 (pre-tension safety belt at the side of passenger), the resistance is too high or open circuit.

OK

14

Ignition circuit 4 (pre-tension safety belt at the side of passenger), the resistance is too low or short circuit.

OK

15

Ignition circuit 4 (pre-tension safety belt at the side of passenger), connects with the grounding

OK

16

Ignition circuit 4 (pre-tension safety belt at the side of passenger), connects with power supply

OK

17

Voltage of power supply is too high

OK

18

Voltage of power supply is too low

OK

19

Malfunction of indicating light connects with power supply or bulb is short circuit.

OK

20

Malfunction of indicating light connects with the grounding or filament is open circuit.

OK

21

Lack/wrong calculation rule parameters

No (change safety airbag

controller (KD4.1))

22

Front impact has been recorded

No (change safety airbag

controller (KD4.1))

23

Communication malfunction

OK

24

Inner malfunction

No (change safety airbag

controller (KD4.1))

25

Impact output (oil pump) pin connects with the grounding

OK

26

Impact output (oil pump) pin short connects with power supply

OK

27

Impact output (central control door lock) pin connects with the grounding

OK

28

Impact output (central control door lock) pin connects with power supply

OK

29

Pre-tension safety belt ignites independently

OK, but most is five times

30

Pre-tension safety belt ignites six times independently

No (change safety airbag

controller (KD4.1))

 247 

there are some malfunctions, indicating light will indicate them. If exterior malfunctions are historical,
after they are removed, indicate will disappear.

one displayed or historical malfunction is only set up again by server. Inner malfunction or “impact
record” of safety airbag controller (KD4.1) could not be set up again, in this situation, it is necessary to
change safety airbag controller (KD4.1).

(3) micro controller, independent indicating light illuminates.

Microprocessor having obvious malfunction state could not work, so it could not control the work of indicat-

ing light. In this situation, indicating light will illuminate directly by applicable circuit without considering the

micro-processor, liking that shown in following:

The battery providing electricity for safety airbag controller (KD4.1) disables: indicating light illumi-
nates by the automatic light driving function.
Inner working voltage loses: indicating light illuminates usually.
New setup caused by the unsuccessful watchdog trigger: indicating light flashes
Micro-processor does not work: indicating light illuminates usually
Insert of connecter of safety airbag controller (KD4.1) is wrong: indicating light illuminates usually by
short circuit stick.

Take example to specify diagnostic step:

If finding indicating light of safety airbag illuminates usually, even if it extinguishes at last, you could check

by follow step. First is to check the part happening malfunction with diagnostic tool.

Then make by the checking step for corresponding position.
a. If scan result is inner malfunction or safety airbag has exploded, at this time, change the ECU directly.
b. Malfunction has been removed.

Supplemental restraint system--Repair

 248