FUEL SYSTEM 5P8961 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the circuit for one of the analog sensors or if one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table    
Description    Conditions which Generate this Code    System Response    
100-3 Engine Oil Pressure Sensor : Voltage Above Normal     The Electronic Control Module (ECM) has detected a voltage on the sensor's signal wire that is greater than 4.8 volts for five seconds.     The code is logged.
The alarm output is activated.
The shutdown output is activated.
The engine is shut down.
The value of the parameter is set to the last value from the sensor that is valid.    
100-4 Engine Oil Pressure Sensor : Voltage Below Normal     The ECM has detected a voltage on the sensor's signal wire that is less than 0.2 volts for five seconds.    
172-3 Intake Manifold Air Temperature Sensor : Voltage Above Normal     The ECM has detected a voltage on the sensor's signal wire that is greater than 4.8 volts for five seconds.    
172-4 Intake Manifold Air Temperature Sensor : Voltage Below Normal     The ECM has detected a voltage on the sensor's signal wire that is less than 0.2 volts for five seconds.    
175-3 Engine Oil Temperature Sensor : Voltage Above Normal     The ECM has detected a voltage on the sensor's signal wire that is greater than 4.8 volts for five seconds.    
175-4 Engine Oil Temperature Sensor : Voltage Below Normal     The ECM has detected a voltage on the sensor's signal wire that is less than 0.2 volts for five seconds.    
542-3 Engine Oil Pressure Sensor - Before Oil Filter : Voltage Above Normal     The ECM has detected a voltage on the sensor's signal wire that is greater than 4.8 volts for five seconds.     The code is logged.
The alarm output is activated.
The value of the parameter is set to the last value from the sensor that is valid.    
542-4 Engine Oil Pressure Sensor - Before Oil Filter : Voltage Below Normal     The ECM has detected a voltage on the sensor's signal wire that is less than 0.2 volts for five seconds.    The following analog sensors are used by this engine:
Differential pressure sensor
Engine oil temperature
Filtered engine oil pressure
Inlet air temperature
Unfiltered engine oil pressureBackground InformationThe ECM continuously creates a pull-up voltage on the signal wire for each sensor. The ECM uses this pull-up voltage in order to detect a problem in the signal circuit. When the ECM detects voltage that is above a threshold on the signal wire, the ECM activates a high voltage -3 diagnostic code. When the ECM detects voltage that is below a threshold on the signal wire, the ECM activates a low voltage -4 diagnostic code.Note: There may be a delay of 30 seconds or more in order for Caterpillar Electronic Technician (ET) to display an active diagnostic code. When you check for a