Great Wall V200. Instruction — part 24

Safety airbag-2

Table 1 SRS-ECU stitch description

5. The maintenance operation must be started after 60 seconds following the removal of negative connection of

accumulator, wrap the negative with insulating tape for insulation.

Due to the capacitance in SRS-ECU to maintain certain power to make the safety airbag release within a certain time after the

power-off of accumulator, the operation must be started after a while to avoid any possible major damaging accident caused

by the safety airbag’s improper release.

6. The parts such as SRS-ECU, safety airbag module as well as clock spring should be removed off and well preserved

providing the temperature is high enough to cause any damage(above93¡æ) in the painting operation.

The failure codes must be debugged with the diagnostic scanner following the repairing of SRS safety airbag system so as to

make alarm lamp work functionally.

Instructions for maintenance

For your safe operation, please read the following instructions prior to your operation.

1. The maintenance of SRS safety airbag must be operated under the procedure and directions instructed in this

chapter.

2. The operation must be done with the test instruments and special tools designated by the chapter.

3. The following parts must be replaced by new ones providing something wrong with them.

a. SRS safety airbag control unit (SRS-ECU)

b. Clock spring module

c. The driver’s side safety airbag module
d. The passengers’ side safety airbag module.

e. Safety airbag wiring harness.

4. The safety airbag electric principles figure and definitions of connector clips are in Figure 1,SRS-ECU stitch

definition in Table 1 and the position and form of safety airbag failures indicator lamp in combined instrument in

Figure 2.

The driver’s side safety airbag, low position

Wire#

Description

Name

Diagnosis request

The driver’s side safety airbag, high position

Passengers’ side safety airbag, high position

Passengers’ side safety airbag, low position

Diagnosis of serial data I/O (K-line)

Safety airbag-3

Safety airbag-4

safety airbag system alarm lamp

impact sensor and diagnosis module

passengers’ side inflation elements and airbag

insulating tape

battery

wire

Safety airbag-5

Test instrument

Instrument

Name

Utility

diagnostic scanner

The alarm lamp

keeps illuminating.

Failure

handling

Debug the

failure codes

Test the systematic failures in

SRS safety airbag system, debug
ECU. failure codes.

The basic failure diagnosis process

The failure code DTC of both present and history-accumulated failures may co-exist.

Caution

The safety airbag alarm lamp flashes for 6 times and then extinguishes when the ignition switch is in ON

position after the installation of new safety airbag system electronic control unit, which demonstrates the

normal function of SRS safety airbag system. In this case the system does not need to be tested, otherwise it

should be diagnosed and repaired.

If the alarm lamp does not illuminate when the ignition switch is in ON position, repair the alarm lamp relevant

circuit and, then further operate to get it into work.

Scan the ECU by connecting

the scanner with k-line

Failure detection

The test for SRS safety airbag alarm lamp

SRS-ECU will execute a series of diagnosis and test to check whether the function of airbag system is prepares. The check can

prevent the restriction system from mis-explosion and ensure the necessary explosion during collision. If found the failure,

SRS-ECU will save a proper failure code and light the alarm lamp to indicate a failure status for the convenience of maintenance.

If connect the pin 2# wire 488# (diagnosis request wire) on the diagnosis port to the ground (wire 50#) for more than 2s, the
safety airbag alarm lamp will flash the code. For detailed position refer to following figure.

safety airbag system alarm lamp

Safety airbag-6

brown white

red

diagnosis plug

black

Failure judgment

1.

Failure record (failure code storage)

When ECU determines the error through the cyclic diagnosis and test, SRS-ECU should saves the corresponding code, first

judgment time, final judgment time and number of occurrence in EEPROM.

RS-ECU can stores 6 failures at most, under voltage failure and two collision records (front and side).

Failure code approved by SRS-ECU

Serial No.

Failure description

Debugging

1

Ignition loop 1 (driver’s front airbag), resistance is too high or open-circuit.

Can

2

Ignition loop 1 (driver’s side front airbag), resistance is too low or short-circuit

Can

3

Ignition loop 1 (driver’s side front airbag), grounding

Can

4

Ignition loop 1 (driver’s side front airbag), connected to power supply

Can

5

Ignition loop 2 (passenger side front airbag), resistance is too high or open-circuit.

Can

6

Ignition loop 2 (passenger side front airbag), resistance is too low or short-circuit

Can

7

Ignition loop 2 (passenger side front airbag), connected to power supply

Can

8

Ignition loop 2 (passenger side front airbag), connected to power supply

Can

9 Power

voltage

is

high

Can

10 Power

voltage

is

low

Can

11

Alarm light failure, connected to power supply or lamp is short-circuit

Can

12

Alarm lamp is failure- grounding or filament is open-circuit.

Can

13

Shortage/failure of algorithm parameter

Cannot (replace the

SRS-ECU)

14

The front collision is recorded

Cannot (replace the

SRS-ECU)

15 Communication

failure

Can

16

Internal failure (refer to following table)

Cannot (replace the

SRS-ECU)

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 safety
belt pre-tightener

Reach the maximum value 6

9

Holding time of ECU energy
(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.

Safety airbag-9

Project 3 functional working (neither possible explosion failure or historical failure).

Table 4.9 indicator lamp’s activities after ignition

2.Failure indication

The alarm lamp will indicate it in case any failure arises. If the external failure is a historical one, the indication will be called off. If

the number of history-accumulated failures is or more than 5, the alarm lamp will keep illuminating albeit no failure emerges. The

case of low power will be excluded.

A displayed or historical failure can but only be reconfigured by the service personnel. An internal failure or impact record can not
be reconfigured, in these cases, SRS-ECU must be replaced.

3.Micro controller-independent alarm lamp illumination

The micro-controller in clear failure status can not work therefore can not control the alarm lamp. In this case, the alarm lamp

will be directly lighted via suitable circuit despite of the micro-controller. As following,

The battery for SRS-ECU fails, the alarm lamp will be continuously lighted through the lamp drive function.

b. No internal working voltage, the alarm lamp keeps illuminating

c. Reconfiguration caused by watchdog’s trigging failure, the alarm lamp flashes.

d. No work of micro-controller, the alarm lamp keeps illuminating
e. Incomplete plugging-in of SRS-ECU connector, the alarm lamp keeps illuminating via shoring bar Next explain the diagnostic

procedure by taking some examples

If the alarm lamp is found keeping illuminating, please test it according to the following procedure even it extinguishes finally.

First test the failure region with the scanner followed by the test in the failure region with the corresponding approaches and

steps.

a If an internal failure or the explosion of safety airbag is scanned, replace the SRS-ECU

b.Troubleshooting

Project 2. The number of history- accumulated failures is or more than one and less than 5. (The case of low power is excluded)

Safety airbag-10

1. Extinguishments of safety airbag system alarm lamp

Troubleshooting

Extinguishments or normal-light of alarm lamp

NO. Troubleshooting

item

Description

1

The warning lamp of safety airbag

system is not displayed.

Safety airbag system warns circuit failure

2

The warning lamp of safety airbag

system is light normally.

Safety airbag system warns circuit failure or external

failure.

1

Extinguishments of safety airbag system alarm lamp

Test status

Safety airbag system warns circuit failure.

Possible causes

No voltage (fuse shutoff)

Combined instrument failure

Failure of wiring harness between instrument cluster and ECU unit

Diagnostic procedure

When first carry out failure test, joggle the wiring harness and plug to test whether there is periodical bad contact in the circuit, if
it so, please confirm whether the plug, terminal and wiring harness well connected and in good condition. If it is not any of previous

cases, operate according to the following steps.

Procedure

Test

Operation

Yes

Place the ignition switch in LOCK

position followed by next step

1

Test other wiring harness and instrument cluster

indicator lamp

·

place the ignition switch in ON position

·

light other alarm and indicator lamps

No

Test the instrument cluster power-supply

system and grounding system (fuse), then

go to step 5.

Yes Next

step

2

Bulb test

Warning:

Incorrect handling with the safety airbag system

units will cause the safety airbag’s improper

release and pretension of safety belt, which will

lead to serene accidents. Please read safety airbag

service warning before handling the safety airbag

units.

·

Place the ignition switch in LOCK position。

·

shut off accumulator negative line and keep the

status for at least 60 seconds.

·

Remove the combined instrument.

Test the connection between the two

corresponding stitches of safety airbag alarm lamp

No

Replace the bulb of alarm lamp.

Safety airbag-11

2. Normal-light of safety airbag system indicator lamp

2

Normal-light of safety airbag system alarm lamp

Test status

Normal-light of safety airbag system alarm lamp

Possible causes

Insufficient battery voltage

ECU internal failure

Combined instrument safety airbag alarm lamp failure

ECU plug misconnects

Combined instrument plug bad-contact

ECU power-supply fuse shutoff or bad contact

Misconnection of ECU plug terminal

Bad contact between ECU plug terminal and grounding wiring

harness.

Driver’s or passengers’ side safety airbag circuit failure.

Procedure

Test

Operation

Yes Next

procedure.

3

Test the wiring harness connection between ECU

unit and instrument cluster.

·

Place the ignition switch in LOCK position。

·

shut off accumulator negative line

·

shut off the instrument cluster plug

·

test the connection between alarm lamp circuit

and its relative circuits

No

Replace the wiring harness and get into

step 5

Safety airbag-12

Begin the test with diagnostic communication with special diagnostic device (X-431 diagnostic tester) and ECU
to find out the failure causes, do the next test providing communication is not successful.

Procedure

Test

O peration

Yes Next

procedure

1

Test the battery

Test the battery voltage

Is the voltage higher 9V?

No

Insufficient battery supply.

Test the charging/discharging

system, then go to step 5.

Yes Next

step

2

Test the wiring harness connection between ECU and

combined instrument.

Place the ignition switch in LOC K position。

Shut off the battery negative.

Open the central channel guard plate.

Shut off the instrument combined connector clip

Connect the negative of battery

Place the ignition switch in ON position.

Check whether the instrument connector clip terminal

voltage is 12V(power supply and instrument line)

No

Check the circuit and continue the

operation according to step 5.

Yes Next

step

3

Place the ignition switch in LOC K position。

Check the connection of corresponding terminals between

instrument connector clip and diagnostic interface

(diagnose the two ends of K-line)

No

Repair or replace the wiring

harness and continue according to

step 5

Yes Next

step

3

Make sure the shutoff of accumulator negative line and

keep the status for at least 1 minute.

Shut off ECU connector clip

Shut off the instrument cluster plug.

Connect the ECU plug terminal 5,7,9 and instrument

cluster plug?

No

Replace the wiring harness and

step 5

Yes Replace

ECU

4

Remove EC U to check the condition of terminal and

whether the shorting bar is broken.

No

Reconnect EC U connector clip

and next step.

Yes

Troubleshooting followed by the

explanations to customers upon

the repairing procedure.

5

Make sure that the failure will never reoccur after

repairing.

Place the ignition switch in LOC K position。

Shut off accumulator negative line and keep the status for

at least 1 minute.

Connect all ECU plugs

Connect the driver’s side safety airbag combined

instrument plug

Connect the passengers’ side safety airbag combined

instrument plug

Connect the driver and passengers’ side pretension safety

belts plugs.

(Vehicles with pretension safety-belts)

Connect clock spring plug

Connect the accumulator negative line

Place the ignition switch in ON position

Does the safety airbag alarm lamp work functionally?

No

Retest the failure symptoms;

repeat from step 1 if the failure

reoccurs.

Safety airbag-13

Internal failure

Failure code

$9071

SRS safety airbag system unit internal failure

Test condition

Warning

The test condition of this failure is the failure code that may not emerge before the test,

DTC conducts the test, and the preparatory work must be done before the test because the

damage to working personnel or system may be caused by the incorrect operation during the

test.

SRS safety airbag system electronic-control unit internal circuit failure.

Possible causes

SRS safety airbag system unit internal failure

Operation

With regard to replacing SRS safety airbag system unit, take references in the removal/installation of safety airbag system

Safety airbag-14

Power-supply

Failure code

$9032

Low power-supply voltage for SRS safety airbag system electronic-control unit

Test condition

Warning

The test condition of this failure is the failure code that may not emerge before the test, DTC conducts the test,

and the preparatory work must be done before the test because the damage to working personnel or system

may be caused by the incorrect operation during the test.

The voltage for SRS safety airbag system unit connector clip is stitch 5 and 6 is under 9V

Possible

causes

Accumulator low voltage

Failure with the wiring harness between accumulator and SRS safety airbag system electronic-control unit

Procedure Test

Operation

Yes Next step

1

Check accumulator

Test accumulator voltage

Is the voltage above 9V

No Accumulator low voltage, test the

recharging/discharging system

Yes Next step

2

Check the wiring harness between accumulator and fuse

panel

Remove fuse panel without releasing the connector clips

Place the ignition switch in ON position

Test the potential of two fuse corresponding contactors, the

potential above 9V?

No Check the wiring harness

Yes Next step

3

Check the wiring harness between fuse panel and SRS

safety airbag system unit connector clip

Warning:

If not correctly handled, the safety airbag module as well

as pretension safety belt may possibly be trigged, released

and tensioned, thus make serene damage to people.

Therefore, please carefully read the repairing warning

before trouble handling. Please take references in safety

airbag system repairing warning

Place the ignition switch in LOCK position

Release accumulator negative wire and wait for 1 minute

plus

Remove steering pillar shell

Release the clock spring connection clips

Remove the PAB trim cover, glove box (passengers’ side

safety airbag is under the trim cover)

Release passengers’ side safety airbag module connector

clips

Release all SRS safety airbag system unit connector clips

Install back the accumulator negative wire,

Place the ignition switch in ON position

Is the potential of SRS safety airbag system unit connector

clips stitch 5,6(grounding) above 9V?

No Replace wiring harness

Safety airbag-15

Yes

Present failure codes
Replace SRS safety airbag system unit
See he removal/installation of SRS
safety airbag system unit
History accumulated failure codes
The end of failure diagnosis

4

Place the ignition switch in LOCK position
Release accumulator negative wire and wait for 1 minute
plus
Remove the left trim cover
Shut off SRS safety airbag system unit translation
connector clips
Install back the accumulator negative wire, place the
ignition switch in ON position
Is the potential of SRS safety airbag system unit connector
clips stitch 5,6(grounding) above 9V?

No Replace

wiring

harness

Drive side failure

Failure code
$9021
$9022
$9024
$9025

Driver’s side safety airbag failure (high or low resistance, shorting grounding, etc.)

Test

condition

Warning
If not correctly handled, the safety airbag module as well as pretension safety belt may possibly be trigged, released
and tensioned, thus make serene damage to people. Therefore, please carefully read the repairing warning before
trouble handling. Please take references in safety airbag system repairing warning
Driver’s side safety airbag
The resistance between the SRS safety airbag system connector clips connectors not within the designated scope
SRS safety airbag system driver’s side airbag relative wiring harness shorting or shutoff

Possible

causes

Driver’s side safety airbag module failure
Clock spring internal failure
Failure of circuit connector clips between clock spring and SRS safety airbag system electronic-control unit
Shutoff or shorting of wiring harness between clock spring and SRS safety airbag system electronic-control unit.
Misconnection of SRS safety airbag system driver’s side airbag generator connector clip

Procedure

Test

Operation

Normal

Next step

1

Check the clock spring
Warning
If not correctly handled, the safety airbag module may possibly be
trigged and released thus make serene damage to people. Therefore,
please carefully read the repairing warning before trouble handling.
Please take references in safety airbag system repairing warning.

Are the relative parts of clock spring normal? (The relation between

stitches, unnecessary shutoff or shorting?) if the present clock spring can
be replaced by a better one.

Abnormal

Replace the clock spring
Take references in the
removal/installation for
safety airbag system and
clock spring

Replace the driver’s side
safety airbag module
T k

f

i

th

Confirm the failure in driver’s side safety airbag module or other parts.
R l

th DAB

d l

ith b tt

Safety airbag-16

Yes Next

step

4

Confirm the failure in clock spring or other parts
configure the special tools fuel and temperature diagnostic instrument
at 2Ω position
Install back the accumulator negative wire
Place the ignition switch in ON place
Any failure code in display?

No

Replace clock spring
Take references in the removal
and installation for safety airbag
system and clock spring.

Normal

Replace SRS safety airbag
system unit; take references in
removal/installation of SRS
safety airbag system unit.

5

Check the wiring harness between clock spring and SRS safety airbag
system electronic-control unit
Place the ignition switch in LOCK position
Release accumulator negative wire and wait for 1 minute plus
Remove PAB trim cover, glove box (passengers’ side safety airbag is
under the trim cover)
Release the passengers’ side safety airbag module connector clip
Release all SRS safety airbag system unit connector clips
Check whether the following troubles are with the harness between
connector clips terminals of SRS safety airbag system unit and clock
spring
Grounding
Power-supply shorting
Shutoff
Is the previous wiring harness normal?

Abnormal

Replace the wire harness

Normal Next

step

6

Check the clock spring connector clip
Remove the steering pillar shell
Release the clock spring connector clip
Is the clock spring connector clip normal?

Abnormal

Replace the wiring harness or
connector clips

Normal Next

step

7

Check clock spring
Remove clock spring
Take references in removal/installation of safety airbag system as
well as clock spring
Check clock spring
Take references in the test for safety airbag system and clock spring.
Is the clock spring normal?

Abnormal

Replace clock spring
Take references in the
removal/installation of safety
airbag system and clock spring.

Normal Next

step

8

Check the wiring harness between clock spring and SRS safety airbag
system electronic-control unit
Place the ignition switch in LOCK position
Release accumulator negative wire and wait for 1 minute plus
Remove PAB trim cover, glove box (passengers’ side safety airbag is
under the trim cover)
Release the passengers’ side safety airbag module connector clip
Release all SRS safety airbag system unit connector clips.
Check whether the following troubles are with the harness between
connector clips terminals of SRS safety airbag system unit and spring
clock.
Grounding
Power-supply shorting
Shutoff
Is the previous harness normal?

Abnormal

Replace clock spring
Take references in the
removal/installation of safety
airbag system, and clock spring

Safety airbag-17

Passengers’ side failure

Failure code

$9015
$9016
$9018
$9019

Passengers’ side safety airbag module (high or low resistance or shorting grounding)

Test condition

Warning

If not correctly handled, the safety airbag module as well as pretension safety belt may possibly be

trigged, released and tensioned, thus make serene damage to people. Therefore, please carefully read the
repairing warning before trouble handling. Please take references in safety airbag system repairing warning
If with passengers’ side safety airbag failure
The resistance between SRS safety airbag system unit connector clip stitch 13 and stitch 14 not within the
designated scope.
The wiring harness shorting between safety airbag system unit stitch 13 and stitch 14
Open loop between SRS safety airbag system unit connector clip stitch 13 and stitch 14,

Possible causes

Passengers’ side safety airbag module failure
The failure of connector clip between passengers’ side safety airbag module and SRS safety airbag system
electronic-control unit
The failure of connector clip between SRS safety airbag system unit and grounding jumper.
The circuit shutoff or shorting between passengers’ side safety airbag module and SRS safety airbag system
electronic-control unit
The circuit shutoff or shorting between SRS safety airbag system unit and grounding jumper
SRS safety airbag system unit failure

Procedure

Test

Operation

Yes Next

step

1

Is the vehicle with passengers’ side safety airbag module

No Step

5

Present failure code
Next step

Check passengers’ side safety airbag connector clips
Warning