PIN 5T2031 - Caterpillar

The control module has two external connections: a 6-pin connector and a 19-pin connector. The control also has one internal serial connector. The 6-pin connector carries the signals for control of the motor for the fuel valve. The pins and the terminations are identified in Table 2.The 19-pin connector includes the connections for several items: power input, manifold air pressure sensor, oxygen buffer, speed sensor, alarm output and spares. The pins and the terminations are identified in Table 3.In addition to the external connectors, the control has a serial connector (type d) on the logic board. This 9-pin connector may be used to monitor the operation of the air/fuel ratio control.
Table 1
Pins and Terminations of the Control's 6-Pin Connector    
Pin     Termination    
"A"     Coil 3 of the motor for the fuel valve    
"B"     Coil 2 of the motor for the fuel valve    
"C"     Coil 4 of the motor for the fuel valve    
"D"     0 to +24 V power supply for coils 2 and 4 (1)    
"E"     0 to +24 V power supply for coils 1 and 3 (1)    
"F"     Coil 1 of the motor for the fuel valve    
( 1 ) If the motor for the fuel valve is actuating, the voltage will vary.
Table 2
Pins and Terminations of the Control's 19-Pin Connector    
Pin     Termination    
"A"     +24 V power supply (1)    
"B"     Return for the +24 V power supply (2)    
"C"     Alarm output (3)    
"D"     +24 V switched supply for the oxygen buffer (4)    
"E"     Return for the oxygen buffer    
"F"     Signal from the oxygen buffer (5)    
"G"     +24 V supply for the inlet manifold pressure sensor (6)    
"H"     Return for the inlet manifold pressure sensor    
"J"     Signal from the inlet manifold pressure sensor (5)    
"K"     +5 V supply for the inlet manifold temperature sensor (6)    
"L"     Return for the inlet manifold temperature sensor    
"M"     Signal from the inlet manifold temperature sensor (7)    
"N"     Spare return 2    
"P"     Spare input 3    
"R"     Spare return 3    
"S"     Spare input 4    
"T"     Ground for the speed sensor's shield    
"U"     Positive input from the speed sensor    
"V"     Negative input from the speed sensor    
( 1 ) The power supply uses a ten amp fuse. Five amperes are required primarily for the oxygen sensor's heater.
( 2 ) The return for the power supply uses a ten amp fuse.
( 3 ) The output for the alarm is normally closed. The switch opens for an alarm condition.
( 4 ) The power supply for the buffer is limited to five amperes. The current is limited by temperature.
( 5 ) The frequency of the PWM signal is 500 Hz.
( 6 ) The power supply for the sensor is limited to