service SSANGYONG MUSSO 2003 Service Manual

SECTION 8B
SUPPLEMENTAL RESTRAINT SYSTEM(SRS)
Specifications . . . . . . . . . . . . . . . . . . . . . . . . 8B-1General Specifications . . . . . . . . . . . . . . . . . . 8B-1
Schematic and Routing Diagrams . . . . . . . . 8B-2 Air Bag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8B-2
Cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8B-3
Function Description . . . . . . . . . . . . . . . . . . 8B-4 Air Bag Module . . . . . . . . . . . . . . . . . . . . . . . . 8B-6
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . 8B-7 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . 8B-7
Self Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . 8B-10
Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . 8B-16
TABLE OF CONTENTS
Caution: Disconnect the negative battery cable before removing or installing any electrical unit or when a tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwisenoted.
SPECIFICATIONS
GENERAL SPECIFICATIONS
Application
Air bag System Deployment Time
Detection Time
Operating Temperature
Storage TemperatureAir Bag Replacement Interval
Voltage Range Current Consumption Acceleration Range Max. Acceleration
Voltage Ramp Energy Reservation Inflator Ignition EnergySquib Resistance
Air Bag Warning Lamp ON Time (When Ignition ON) Description
< 20ms< 5ms
-40°C ~ +85°C
-40°C ~ +90°C
Every 10-year after installation 9-16V
5ms after ignition switch ON < 1A,
5ms ~ 5sec. <300mA, after 5sec. < 100mA
+/-50g
+/-600g pulse 0.5 ~ 2.0 V/s
150ms after battery disconnection
4.3mJ
2.15 ± 0.35
6 sec.Air Bag Diagram . . . . . . . . . . . . . . . . . . . . . . 8B-17
Maintenance and Repair . . . . . . . . . . . . . . 8B-18
On-Vehicle Service . . . . . . . . . . . . . . . . . . . . . 8B-18
Air Bag Module . . . . . . . . . . . . . . . . . . . . . . . 8B-18
Clock Spring . . . . . . . . . . . . . . . . . . . . . . . . . 8B-19
Air Bag Control Unit (AC4) . . . . . . . . . . . . . . 8B-21
General Description and System Operation . . . . . . . . . . . . . . . . . . . . . . . . 8B-22
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 8B-22
Caution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8B-22

SUPPLEMENTAL RESTRAINT SYSTEM(SRS) 8B-3
CAUTIONS
Failure to follow the correct service procedure can cause air bag damage or personal injury due to unexpected air
bag deployment. Before service (removal and installation of part, check for replacement), please be weal noticed offollowing items for your correct service.
1. For service, turn the ignition switch to ‘LOCK’ position and wait for 30 seconds after disconnecting the negative battery cable.
2. If the vehicle collapsed, remove the air bag ECU first to reserve the crash records.
3, Never use other vehicles’ air bag components and replace with specified new part.
4. Never disassemble or repair the air bag module, air bag unit and wiring harness to re-use.
5. Replace the air bag module and air bag unit with new if it dropped, cracked or damaged.
6. Only qualified technicians in service shop should check or repair the air bag,
7. Before service, should be well noticed of warning labels on the vehicle.
A. Sun Visor Side
[Warning] Pull down the sun visor and see SRS air bag warning lamp on the head lining. B. Head Lining
[Warning]
1 . This vehicle is equipped with air bag. Air bag is supplemental device for the seatbelt. Fasten your seatbelt.
2. This air bag should be replaced by authorized supplier within replacement intervals.
3. When the ignition key is turned to ON position, SRS warning lamp will turn on for 6 sec. and go off. In this case, the system is normal. For the following cases, see service manual. - SRS warning lamp does not turn on. - SRS warning lamp does not go off.- SRS warning lamp continues to blink.
C. Steering Wheel Body Inner
[Warning] Before removing the steering wheel, read service manual first. Set the front wheels straight forward
and align the center position marks of SRS clock spring. Improper removal or installation of the steering wheel can damage the SRS components. D. Engine Compartment
[Warning] This vehicle is equipped with air bag. Before checking the engine compartment, read servicemanual first. Faultuy check and service can cause SRS air bag deployment and system defects that can be led to severe damage. E. Battery Cable
[Warning]
Before disconnecting the battery power, read service manual first.

SUPPLEMENTAL RESTRAINT SYSTEM(SRS) 8B-11
Self-Diagnosis List
Fault
CodeDefects Service Hint
01 Driver’ s squib (+) side No. 1 Short of (+) side No. 1 in the driver ’ s squib circuit.
Check connection of connector.
Check the ECU.Appli-
cation
02 Driver’ s squib (+) side No. 2 Short of (+) side No. 2 in the driver ’ s squib circuit.
Check connection of connector.
Check the ECU.X
03 Driver’ s squib (+) side No. 3 Short of (+) side No. 3 in the driver ’ s squib circuit.
Check connection of connector.
Check the ECU.X
04 Driver’ s squib (+) side No. 4 Short of (+) side No. 4 in the driver ’ s squib circuit.
Check connection of connector.
Check the ECU.X
05 Driver’ s squib ground (-) side No. 1 Short of ground side No. 1 in the driver ’ s squib
circuit.
Check and replace the ECU.
06 Driver’ s squib ground (-) side No. 2 Short of ground side No. 2 in the driver ’ s squib
circuit.
Check and replace the ECU.X
07 Driver’ s squib ground (-) side No. 3 Short of ground side No. 3 in the driver ’ s squib
circuit.
Check and replace the ECU.X
08 Driver’ s squib ground (-) side No. 4 Short of ground side No. 4 in the driver ’ s squib
circuit.
Check and replace the ECU.X
09 Energy shutdown switch No. 1 Air bag control unit internal defects.
Check and replace the ECU.
10 Energy shutdown switch No. 2 Air bag control unit internal defects.
Check and replace the ECU.X
11 Energy shutdown switch No. 3 Air bag control unit internal defects.
Check and replace the ECU.X
12 Energy shutdown switch No. 4 Air bag control unit internal defects.
Check and replace the ECU.X
13 Ignition switch wire No. 1 Air bag control unit internal defects.
Check and replace the ECU.
14 Ignition switch wire No. 2 Air bag control unit internal defects.
Check and replace the ECU.X
15 Ignition switch wire No. 3 Air bag control unit internal defects.
Check and replace the ECU.X
16 Ignition switch wire No. 4XAir bag control unit internal defects.
Check and replace the ECU.

8B-12 SUPPLEMENTAL RESTRAINT SYSTEM(SRS)
Fault
CodeDefects Service HintAppli-
cation
17 Squib No. 1 resistance
18 Squib No. 2 resistanceX
19 Squib No. 3 resistanceX
20 Squib No. 4 resistanceX
21 Squib No. 1 resistance
22 Squib No. 2 resistanceX
Driver ’ s squib resistance is higher than standard (4.5±0.5W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.
Driver ’ s squib resistance is higher than standard(4.5±0.5W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.
Driver ’ s squib resistance is higher than standard (4.5±0.5W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.
Driver ’ s squib resistance is higher than standard (4.5±0.5W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.
Driver ’ s squib resistance is lower than standard(1.4±0.3W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.
Driver ’ s squib resistance is lower than standard (1.4±0.3W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.
23 Squib No. 3 resistanceXDriver ’ s squib resistance is lower than standard (1.4±0.3W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.

SUPPLEMENTAL RESTRAINT SYSTEM(SRS) 8B-13
Fault
CodeDefects Service HintAppli-
cation
24 Squib No. 4 resistance
X
25 Energy reserve No. 1 voltage
26 Energy reserve No. 2 voltageX
27 Energy reserve No. 3 voltageX
28 Energy reserve No. 4 voltageX
29 Energy reserve No. 5 voltage
30 Energy reserve No. 6 voltage
31 Energy reserve No. 1 current off capacity
32 Energy reserve No. 2 current offcapacityX
33 Energy reserve No. 3 current offcapacityX
34 Energy reserve No. 4 current off
capacityX
35 Energy reserve No. 5 current offcapacity
36 Condensor voltage
37 Collision times checksum
Driver ’ s squib resistance is lower than standard
(1.4±0.3W).
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Replace the squib wire.
Plus side short : 7k, ground side short : 6kW.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
4 1 Major USAAir bag control unit internal defects.
Check and replace the ECU.
38 Driver’ s acceleration sensor
39 Driver’ s acceleration sensor off-set
40 Arming sensor

Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.

8B-14 SUPPLEMENTAL RESTRAINT SYSTEM(SRS)
Fault
CodeDefects Service HintAppli-
cation
42 Over heat
4 3 SENS
44 Standard band gap
45 Temperature sensor
46 Warning lamp
47 Battery voltage
49 Fault code list
5 0 USA communication
51 LSA communication
52 No EEPROM program
53 EEPROM checksum
5 4 EEPROM map
55 External watchdog 1
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Open/short in the warning lamp circuit.
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Power wire voltage is out of standard voltage (9 - 16V).
Check the battery for voltage and charging.
Check related circuits for open/short.
Check connection of connector.
Check the ECU.
Air bag control unit internal defects.
Check the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
56 Arming sensor-no close
57 RAM check
5 8 System
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.
59 External watchdog 2
60 Pulse
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.

SUPPLEMENTAL RESTRAINT SYSTEM(SRS) 8B-15
Fault
CodeDefects Service HintAppli-
cation
127 Collision signal
128 Collision number
Air bag control unit internal defects.
Check and replace the ECU.
Air bag control unit internal defects.
Check and replace the ECU.

8B-18 SUPPLEMENTAL RESTRAINT SYSTEM(SRS)
MAINTENANCE AND REPAIR ON-VEHICLE SERVICE AIR BAG MODULE Removal & Installation Procedure
1. Remove the steering wheel rid (LH,RH) with a screwdriver.Installation Notice Each position mark (LH,RH) is stamped on the inner surface of the rids.
Tightening Torque 7 - 11 Nm
3. Disconnect the connectors and remove the air bag module.
4. Installation should follow the removal procedure in thereverse order.
2. Unscrew the bolts from both sides.
Installation Notice

SUPPLEMENTAL RESTRAINT SYSTEM(SRS) 8B-21
AIR BAG CONTROL UNIT(AC4) Removal & Installation Procedure AC4 is installed on the center portion of the front floor tunnel.
Built-in accelerometer sensor detects collision and determines action or non-action and ignition time. Notice
Do not disassemble the AC4 to repair. If defective, replace it. AC4 should not be shocked or vibrated by dropping on the ground or bumping. Replace the AC4 with new after air bag inflation.
1. Disconnect the negative battery cable and wait for 30seconds before starting service. Notice Though battery cable is disconnected, air bag control unit will maintain backup power for 150ms and air bag can beinflated, so wait for min.30 seconds.
2. Remove the console box and center fascia panel assembly.
3. Remove the heater control switch and audio assembly.
4. Remove the lower side panel of the driver ’ s portion and glove box.
5. Remove the lower main panel.
6. Release the lock lever of the AC4 connector and disconnect the connector.
7. Unscrew 3 nuts and remove the AC4.
NoticeFor installation, horizontal position should be secured for the better changes of collision pulse between the vehiclebody and air bag control unit.
8. Installation should follow the removal procedure in the reverse order.
Inspection Procedure
1. Check AC4 case and welt bolts for crack or deformation.
2. Check connector, lock lever and terminal for deformation. NoticeReplace the AC4 with new if dust, deformation or corrosion found.

8B-22 SUPPLEMENTAL RESTRAINT SYSTEM(SRS)GENERAL DESCRIPTION
AND SYSTEM OPERATION
INTRODUCTION SRS (Supplemental Restraint System) air bag protects driver and passenger by inflating air bag under collision and seat belt pre - tensioner is a supplemental equipment for seat belt
reducing shocks from the collision by pulling passenger’ s bodyagainst seat back at the same time of air bag inflation. Air bag unit has diagnosis functions and indicates system malfunctions to the driver by turning on the air bag warninglamp. CAUTION Perform the service procedures for the air bag system as ordered, if not, the air bag can be operated suddenly and it
could result in damage of air bag or injury. Before service(removal, installation, checking and replacement of parts),
observe the following instructions and service correctly.
1. To service, turn the ignition switch to ‘LOCK’ position and disconnect the negative battery cable and continue the procedures after approx. 30 seconds.
2. If the vehicle is damaged due to accident, remove the air bag ECU first to get the accident records.
3. Never use the other vehicle’s air bag parts and replace with genuine part, if required.
4. Do not disassemble or repair the air bag module, air bag unit and wiring harness to reuse.
5. Replace the air bag unit or air bag module if dropped, cracked or damaged.