245

4. Trouble Identification

(1) Trouble Record (DTC storage)

When the circular diagnostic tests are involved in identification of a trouble, the SRS ECU (HAE2.5) will

store relevant codes, first/last diagnosis time and frequency of the trouble in EEPROM.

SRS ECU (HAE2.5) can store up to 6 troubles, low voltage trouble as well as two crash records (front

and side).

The transmit of the DTCs are carried out in the way that the SRS ECU£¨HAE2.5£©via serial data

interface of the maintenance procedures assign the codes to the diagnostic detector.

No.

Trouble Description

Troubleshooting

1

Ignition circuit 1 (driver airbag), high resistance or open

circuit

Yes

2

Ignition circuit 1 (driver airbag), low resistance or short

circuit

Yes

3

Ignition circuit 1 (driver airbag), groun d

Yes

4

Ignition circuit 1 (driver airbag), connected to power

source

Yes

5

Ignition circuit 2 (passenger airbag), high resistance or

open circuit

Yes

6

Ignition circuit 2 (passenger airbag), low resistance or

short circuit

Yes

7

Ignition circuit 2 (passenger airbag), groun d

Yes

8

Ignition circuit 2 (passenger airbag), connected to power

source

Yes

9

Ignition circuit 3 (driver seat belt pretensioner), high

resistance or open circuit

Yes

10

Ignition circuit 3 (driver seat belt pretensioner), low

resistance or short circuit

Yes

11

Ignition circuit 3 (driver seat belt pretensioner), groun d

Yes

12

Ignition circuit 3 (driver seat belt pretensioner),

connected to power source

Yes

13

Ignition circuit 4 (passenger seat belt pretensioner), high

resistance or open circuit

Yes

14

Ignition circuit 4 (passenger seat belt pretensioner), low

resistance or short circuit

Yes

15

Ignition circuit 4 (passenger seat belt pretensioner),

ground

Yes

16

Ignition circuit 4 (passenger seat belt pretensioner),

connected to power source

Yes

17

High voltage of power source

Yes

18

Low voltage of power source

Yes

19

Warning light trouble-connected to power source or

short circuit of the light bulb

Yes

20

Warning light trouble-ground or filament open circuit

Yes

21

Missing/mistake of the algorithm parameters

No (replace SRS ECU (HAE2.5))

22

Previous crash recorded

N

o (replace SRS ECU (HAE2.5))

DTCs as recognized by SRS ECU (HAE2.5)

246

 The transmit of the DTCs are carried out in the way that the SRS ECU (HAE2.5) via serial data interface

of the maintenance procedures assign the codes to the diagnostic detector.

23

Communication trouble

Y es

24

Internal trouble (see the follow ing table)

N o  (replace  SRS  ECU   (H A E2.5))

25

P A D S （ passenger airbag deactivation
sw itch） , connected to pow er source or open
circuit

Y es

26

P A D S （ passenger airbag deactivation
sw itch） , ground or short circuit

Y es

27

P A D S (passenger airbag sw itch), trouble

Y es

28

Crash output pin, ground

Y es

29

Crash output pin, short circuited to pow er
source

Y es

30

P A D I (passenger airbag deactivation sw itch
indicator light) error, connected to pow er source
or light bulb short circuit

Y es

31

P A D I (passenger airbag deactivation sw itch
indicator light) error, ground or open circuit

Y es

32

Seat belt pretensioner separate ignition

Y es, up to 5 times

33

Seat belt pretensioner separate ignition for 6
times

N o  (replace  SRS  ECU   (H A E2.5))

No.

Trouble Description

DTC

1

Ignition circuit 1 (driver airbag), high resistance or open circuit

B1 346

2

Ignition circuit 1 (driver airbag), low resistance or short circuit

B1 347

3

Ignition circuit 1 (driver airbag), ground

B1 348

4

Ignition circuit 1 (driver airbag), connected to power source

B1 349

5

Ignition circuit 2 (passenger airbag), high resistance or open circuit

B1 352

6

Ignition circuit 2 (passenger airbag), low resistance or short circuit

B1 353

7

Ignition circuit 2 (passenger airbag), ground

B1 354

8

Ignition circuit 2 (passenger airbag), connected to power source

B1 355

9

Ignition circuit 3 (driver seat belt pretensioner), high resistance or open circuit

B1 361

10

Ignition circuit 3 (driver seat belt pretensioner), low resistance or short circuit

B1 362

11

Ignition circuit 3 (driver seat belt pretensioner), ground

B1 363

12

Ignition circuit 3 (driver seat belt pretensioner), connect to power source

B1 364

13

Ignition circuit 4 (passenger seat belt pretensioner), high resistance or open
circuit

B1 367

Diagnostic DTCs

247

(2) Internal troubles

The micro controller can check the following items not

only in the initiation check but also in the circular diagnos-

tic check.

1

Trigger transistor of ignition circuit: high-end transistor

can be checked not only in the initiation check but

also in the circular diagnostic check. However, since

the low-end transistor is open when connected in short

circuit to power source, it can only be checked in the

initiation check to avoid explosion.

2

The ignition voltage is provided by supercharge

converter.

3

The acceleration sensor performs selfcheck in the

initiation check.

4

Range of allowed deviation of acceleration sensor in the circular diagnostic check.

5

Microcontroller includes AD converter, ROM, RAM, etc.

6

Status of safety sensor.

NOTICE

The connectors of the squib circuit contain a

shorting bar. When the connector is not

connected, the unexpected deployment is

caused by the short in the circuit arising from

the contact of the positive (+) and negative (-)

terminals or the static electricity. If there is

poor connection for connectors, the symptom

may not be removed even when the shorting

bar is connected.

14

Ignition circuit 4 (passenger seat belt pretensioner), low resistance
or short circuit

B1 368

15

Ignition circuit 4 (passenger seat belt pretensioner), ground

B1 369

16

Ignition circuit 4 (passenger seat belt pretensioner), connect to
power source

B1 370

17

High voltage of power source

B1 111

18

Low voltage of power source

B1 112

19

Warning light trouble-connected to power source or light bulb short
circuit

B2 500

20

Warning light trouble-ground or filament open circuit

B2 500

21

Missing/mistake of the algorithm parameters

B1 661

22

Previous crash recorded

B1 650

23

Communication trouble

B1 407

23

Internal trouble (see the following table)

B1 620

24

PADS （ passenger airbag deactivation switch ） , connected to
power source or open circuit

B1 527

25

PADS （passenger airbag deactivation switch）, ground or short
circuit

B1 528

26

PADS (passenger airbag deactivation switch), trouble

B1 529

27

Crash output pin, ground

B1 676

28

Crash output pin, short circuited to power source

B1 677

29

PADI (passenger airbag deactivation switch indicator light) error,
connected to power source or light bulb short circuit

B2 505

30

PADI (passenger airbag deactivation switch indicator light) error,
ground or open circuit

B2 505

31

Seat belt pretensioner separate ignition

B1 657

32

Seat belt pretensioner separate ignition for 6 times

B1 658

248

An external watchdog can check the operation situation of the microcontroller. The failure of the microcontroller

can trigger the watchdog, which in turn can reset the microcontroller and turn on the warning light.

No.

List of Troubles

Trouble Description

1

Microcontroller

      

   AD converter or EEPROM trouble (in

case of RAM and ROM failure, the
microcontroller will reset and the warning
light will light up.)

        

 Activate trouble

     

Check the circuit trouble

         

Activate trouble

       

 Check the circuit trouble

        

 Activate trouble

        

 Check the circuit trouble

         

Activate trouble

        

 Check the circuit trouble

         

Activate trouble

       

 Check the circuit trouble

         

Activate trouble

       

 Check the circuit trouble

6

Ignition voltage

        

 Low

7

Watchdog/reset

         

Trouble

8

Maximum times of explosion of the seat belt

pretensioner

         

6

9

Energy storage time (self-support time)

         

Short

         

Range of deviation

        

 Sensor not in steady mode

         

Sensor selfcheck trouble

11

Continuous abortion of ignition circuit check

         

Nonexecution of circular diagnostic test

(Repeated algorithm calculation)

        

 Close for 2 or more than 2 seconds

       

  Safety sensor is open circuit when

calculating the trouble with algorithm

13

Ignition current

        

 All the ignition currents are normal

when the current SRS is deployed

14

No confirmation of side SRS ignition

        

 Even if the SRS ECU (HAE2.5) have

received for 5 times the ignition information

during the HSIS ignition cycle, the side SRS

airbag ignition can not be verified by SRS

ECU (HAE2.5).

Seat belt pretensioner ignition circuit (if realized)

5

Passenger seat belt pretensioner ignition circuit

(if realized)

2

Passenger airbag ignition circuit

3

Passenger airbag ignition circuit (if realized)

[Table] Internal troubles predicted by SRS ECU (HAE2.5) 

10

Accelerometer

12

Safety sensor

6

Driver airbag ignition circuit (if realized)

7

Passenger airbag ignition circuit (if realized)

4