Safety airbag-7
Description of flash code
The failure code transmission is completed by SRS-ECU’s input to the defined diagnostic scanner through the maintenance system’s
serial data interface. (X-431 diagnostic scanner) Failure code of diagnosis
Failure Failure code Flash code
1 No storage error $12
2 Front airbag driver’s, high resistance $9,021 $21
3 Front airbag driver’s , low resistance $9,022 $22
4 Front airbag driver ’s, short-circuit of GND $9,024 $24
5 front airbag driver ’s , short –circuit of VBATT $9,025 $25
6 front airbag passenger, high resistance $9,015 $15
7 front airbag passenger, low resistance $9,016 $16
8 front airbag passenger , short-circuit of GND $9,018 $18
9 Front airbag passenger , short-circuit of VBTT $9,019 $19
10 High voltage of battery $9,031 $31
11 Low voltage of battery $9,032 $32
12 Failure of alarm lamp $9,061 $61
13 Internal failure (replace SDM) $9,071 $71
14 Front collision record $9,051 $51
15 Side collision driver’s record $9,056 $56
16 Side collision passenger record $9,057 $57
17 Retightened safety belt collision $9,058 $58
18 Beyond the allowable repeat usage times $9,054 $54
3. Interior failure
The micro controller can test the following items not only in starting detection but also in cyclic diagnosis detection.
a. Ignition circuit triggers the transistor: The high-side transistor is detected not only in the starting detection but also in the
circulation diagnosis. But for the low-side transistor is opened when is connected to power supply directly, so the low-side
transistor only can be detected in the starting detection to avoid the misexplosion.
b. The ignition voltage is provided by the booster transformer.
c. The acceleration sensor is detected by itself when start the detection.
d. Allowable deviation scope of acceleration sensor in circulation diagnosis.
e. Micro controller includes (AD converter, ROM, RAM etc.)
f. Status of safety sensor
Cautions:
Connector of explosion tube circuit has the short-circuit bar. When the connector is not connected, the end (+) of
explosion tube is connected to end (-) directly to prevent the failure outspread caused by static. When the connector
is bas and short-circuit bar is connected, the failure may not be eliminated.
An external watch dog can detect the operating status of micro controller. It can trigger the watchdog when the micro con
troller has failure. The watch dog will reset the micro-controller and light the alarm lamp.
Safety airbag-8
Internal failure determined by SRS-ECU
Serial
No. List of failure Description of failure
1 Micro-controller AD converter or EEPROM is faulty (the micro controller will be reset
and alarm lamp is light when the RAM has failure.)
2 Driver’s front airbag ignition loop Enable the failure
Measure the failure of loop
3 Passenger front airbag ignition loop
(if realized) Enable the failure
Measure the failure of loop
4 Seat safety belt preloaded ignition loop
(if realized) Enable the failure
Measure the failure of loop
5 Passenger side safety belt preloaded
ignition loop (if realized) Enable the failure
Measure the failure of loop
6 Driver’s side airbag ignition loop
(if realized) Enable the failure
Measure the failure of loop
7 Passenger side airbag ignition loop
(if realized ) Enable the failure
Measure the failure of loop
8 Maximum times of explosion of safet y
belt pre-tightener Reach the maximum value 6
9 Holding time of ECU ener gy
(self-supply time) Too short
10 Accelerometer Deviation range
Sensor not in constant, stable model
Sensor tests the failure itself
11 The measurement of ignition loop is
rejected continuously No cycling diagnosis test (duplicated calculation)
12 Safety sensor Calculate the safety sensor open-loop using the method that power-off
for 2 or more than 2 seconds is considered as passing
13 Initial firing current All initial firing current in normal status when the front airbag releases.
14 The ignition of side airbag is not
determined. Though SRS-ECU has received ignition information for 5 times during
HSIS cycling ignition, the ignition can not be determined due to the side
safety..
Debug the failure codes
Approach 1. The failure codes will be debugged following the ECU’s receipt from the X-431 diagnostic tester of the debugging
failure codes order through the serial interface, however, if an internal failure code is recorded or one impact is
recorded, the debugging will not be executed.
Approach 2. Ground 488# line for 5 times in 10 seconds to debug the failure codes.
Failure status display (alarm lamp keeps illuminating).
1. Bulb test
SRS-ECU will light the alarm lamp in order to test the bulb after working voltage is provided to it through the battery. The lamp
will flash for 6 times and then extinguish at 1HZ in the initial phase. The alarm lamp will keep illuminating after the working
voltage is provided in order to inform the driver’s system failures. The alarm lamp will keep illuminating for 6 seconds after the
ignition on and then be extinguished if the history-accumulated failures are less than five times. In the initial phase, SRS-ECU will
not prepare to test impact and stop release till the circuit is stable. Therefore, alarm lamp’s display manner will be one of
following projects in the initial phase. (Table 4.9).
Project 1. If the impact is recorded or the number of history accumulated failures is or more than 5,the alarm lamp will keep
illuminating, simultaneously, it will also keep illuminating if there is a possible explosion failure.
