2003 SSANGYONG MUSSO sensor

FATC-HAVC 7D-15
TROUBLESHOOTING Check and Service Incar sensor is a sensor that detects interior air temperature and a thermistor that decreases its resistance when temperature up and increases when temperature down.
1. Check that there are incar sensor fault code (11,12) by using self-diagnosis function.
2. Disconnect incar sensor 2-pin connector that installed on
inner lower instrument panel cover of driver ’s side and
remove the sensor.
3. Check that measured resistance value among incar sensor terminals is as shown in the right side graph. Notice Measure resistance value by soaking the sensor in the ice water and check changes in resistance values after soaking
it in the very hot water.
4. If resistance value is out of specification, replace the incar sensor.
5. Install the sensor and turn the ignition switch to ON position and check that voltage between No. 12A terminal of incar
sensor and body (-) is 5V.
6. Check current between the No. 12B and 12A connector terminals of the incar sensor and the No. 1 and 5 connector terminals of the airconditioner control unit and repair the wire if defective.

7D-16 FATC-HAVC
910
Ambient sensor connector
2

0.5W
Airconditioner control unit connector
V
5

0.5BL
Ambient Sensor Ambient sensor is a sensor that detects ambient temperature and a thermistor that decreases its resistance when temperature up and increases when temperature down.
1. Check that there are ambient sensor fault code (13,14) by
using self-diagnosis function.
2. Disconnect ambient sensor 2-pin connector that installed on front right side of the frame and remove the sensor.
3. Check that measured resistance value among ambient sensor terminals is as shown in the right side graph. Notice Measure resistance value by soaking the sensor in the ice water and check changes in resistance values after soaking
it in the very hot water.
4. If resistance value is out of specification, replace the ambient sensor.
5. Install the sensor and turn the ignition switch to ON position and check that voltage between No. 10 terminal of the
ambient sensor and body (-) is 5V.
6. Check current between the No. 10 and 9 connector terminals of the ambient sensor and the No. 2 and 5 connector terminals of the airconditioner control unit and repair the wire if defective.

FATC-HAVC 7D-17
7b7a
Water sensor connector
3

0.5RB
Airconditioner control unit connector
V
5

0.5BL
Water Sensor
Water sensor is a thermistor that detects engine coolant temperature to operate the blower speed to LO when water temperature is less than 50.
1. Check that there are water sensor fault code (15,16) by
using self-diagnosis function.
3. Check that measured resistance value among water sensor terminals is as shown in the right side graph. Notice Measure resistance value by soaking the sensor in the ice water and check changes in resistance values after soaking
it in the very hot water.
4. If resistance value is out of specification, replace the water sensor.
5. Install the sensor and turn the ignition switch to ON position and check that voltage between No. 7a terminal of the water
sensor and body (-) is 5V.
6. Check current between the No. 7a and 7b connector terminals of the water sensor and the No. 3 and 5 connector terminals of the airconditioner control unit and repair the wire if defective.
2. Disconnect water sensor 2-pin connector that installed on
the heater unit of inner instrument panel and remove the
water sensor.

7D-18 FATC-HAVC Sun load Sensor Sun load sensor is a photo diode that detects lights. Resistance of diode can be measured as current by using multimeteraccording to increasing sun loads.
1. Check current on the circuits between the sun load sensorand the airconditioner control unit.
2. Turn the ignition switch to ON position and check that voltage between No. 13a terminal of the sun load sensor and vehicle
ground is 5V.
3. Measure current between No. 13a terminal of the sun load sensor and No. 11 terminal of the control unit and check it isas shown in the below graph.
4. If current value is out of specification, replace the sun load sensor.

8B-4 SUPPLEMENTAL RESTRAINT SYSTEM(SRS)FUNCTION DESCRIPTION
Air Bag Control Unit (AC4) Air bag control unit (AC4) is installed on the center portion of the front floor tunnel. It is a central control unit that control all functions and determines whether deploy the air bag or not with the collision signal from the built-in accelerometer sensor and has function of diagnosingsystem defects. Internal air bag control unit is consisted as follows;
Microprocessor
ASICs (Upper side ASIC & lower side ASIC)
Accelerometer sensor
Arming sensor
System energy backup condenser
Squib energy backup condenser

SUPPLEMENTAL RESTRAINT SYSTEM(SRS) 8B-7
DIAGNOSIS
DESCRIPTION Air bag control unit continuously controls system function as follows during ignition ON or driving.
- Recognition of collision
- Internal diagnosis
- External diagnosisIf recognize or detect defects, warning lamp will turn on. If there is danger of improper deployment, the system will enter overall shutdown status and the air bag will not inflate. Air bag control unit will store detected internal and external defects in the EEPROM. System Control
Battery Voltage Check
Battery voltage will be monitored continuously. If voltage is out of normal operating range, all system diagnosis will stop and warning lamp turn on. Battery Voltage (V)< 8.7
9 - 16
> 16.3
Function
System diagnosis stops and warning lamp turns on Normal operation range
System diagnosis stops and warning lamp turns on
Squib Diagnosis It checks not only high (4.50.5) or low (1.40.5) resistance but also short resistance (1- 10k) status between the battery and ground to indicate defects in squib line by blinking warning lamp. Air bag control unit (AC4) can measure squib resistance.
Warning Lamp Turning On Air bag control unit detects system defects during ignition ON or driving and displays following 2 warning lamps.
- Warning lamp ON: internal defects of the air bag control unit
- Warning lamp blinking: higher resistance than standard in the squib line or short at the battery or ground, Safety Function Check It checks defects during operation of the arming sensor If the sensor is shorted for more than 2 seconds, the module will enter overall shutdown mode.
Temperature Sensor
Function of the temperature sensor will be monitored continuously. If there is fault due to defective sensor or short, the lamp will turn on and program will take calibration temperature (25) of collision conditions. Power Supply Airbag control unit operates in 9-16v and the characteristic of the system has backup condenser to supply the power for max.150ms if there is power defect during collision.

SUPPLEMENTAL RESTRAINT SYSTEM(SRS) 8B-9
Diagnosis Air bag control unit diagnoses each function in the intervals of 250ms - 20 sec. during start-up or driving to prevent unwanted air bag deployment. If there is defect, it turns on or blinks warning lamp to indicate defects in the air bag
system to the driver. And fatal defect is found, air bag control unit enters overall or partial shutdown status and fault code will be stored. Air bag control unit diagnoses following items.- Ignition TR - Acceleration
- Microprocessor, RAM and ROM
- Watchdog - Shutdown Switch
Diagnosis Condition Diagnosis ItemsStart-up (ignition ON)
During Driving
Lamp Blinking Mode There are 2 kinds of blinking mode
1. When system internal fault is found, the lamp will stay on.
2. The lamp will blink according to external fault and there are 2 blinking codes.
Blinking code 1 (Squib resistance fault in the driver’ s air bag squib line)
Blinking code 2 (Squib short on plus and minus in the air bag squib line)Lamp blinking code is as follows. The last blinking will be within 0.5 sec. and 1 cycle of blinking will be repeated every 5 seconds.
Blinking Code 1
(Sec.) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Blinking Code 3
(Sec.) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 - Squib resistance - Squib line short to battery and ground - Energy reserve system - Lamp output- Battery voltage- ASIC communication- Arming sensor - ASIC overheating - RAM and W/D- EEPROM

8B-10 SUPPLEMENTAL RESTRAINT SYSTEM(SRS)
1. Position the ignition switch to ‘OFF’.
2. Connect the harness connector of scanner to the diagnosissocket in engine compartment.
3. Turn the ignition switch to ‘ON’ position.
4. Select “Electronic control vehicle diagnosis” from function selection display and press ‘Enter’ .
5. Select “Musso (’98 model year)” from vehicle model selection display and press ‘Enter’ .
6. Select “Electronic air bag” from control system selection display and press ‘Enter’ .
7. Select “Self-diagnosis” from diagnosis item selection display.
Notice
Check sensor value of output display, if necessary.
8. Determine the fault code and trace defective component.
NoticeRefer to self-diagnosis list.
SELF DIAGNOSIS