CONTROL GP-UNPROGRAMMED 3577442 - Caterpillar

Illustration 1 g01022646
133-9014 Temperature Sensor (Evaporator)
Illustration 2 g01022866
147-0387 Temperature Sensor (Fresh air) 147-0387 Temperature Sensor (Outlet air) 147-0387 Temperature Sensor (Cab air) Sensors are hard wired from the factory. Illustration shows replacement sensor.
Choose the sensor that needs to be tested. Refer to table 1 for a list of error codes. Proceed to step (2) for error code 008. Proceed to step (3) for error codes 001, 002 and 004.
Table 1
Error Code    Sensor    
"001"     Temperature Sensor (Fresh air)    
"002"     Temperature Sensor (Outlet air)    
"004"     Temperature Sensor (Cab air)    
"008"     Temperature Sensor (Evaporator)    
Check the resistance of the sensor. Compare the resistance value to the values on table 2.Expected Result: The resistance of the sensor is within specifications.Results:
OK - Replace the control module.
NOT OK - Replace the sensor.
Table 2
Resistance of Temperature Sensors    
Temperature    Cab air, Fresh air and Outlet air temperature sensor resistances    Temperature Sensor (Evaporator)    
0°C (32°F)     13 K to 19 K ohms     66 K 660 ohms (1)    
10°C (50°F)     7.9 K to 11.7 K ohms     N/A    
20°C (68°F)     4.8 K to 5 K ohms    
25°C (77°F)     4 K ohms    
30°C (86°F)     3.1 K to 3.3 K ohms    
40°C (104°F)     2.1 K to 2.3 K ohms    
( 1 ) Check the resistance of the sensor at the evaporator by placing the sensor in a tub of ice water.
Clip wires to the sensor and check the resistance value. Compare the resistance value to the values on table 2.Expected Result: The resistance of the sensor is within specifications.Results:
OK - Replace the control module.
NOT OK - Install a 102-8807 Connecting Plug Kit and a new 147-0387 Temperature Sensor Assembly. You will also need two 8T-8730 Connector Sockets .