SWITCH AS-PRESSURE 2014159 - Caterpillar

During normal operation, each pressure sensor outputs a signal voltage that accurately represents the pressure that is sensed by the sensor. However, certain circuit conditions can cause a signal voltage to become inaccurate.During each key on event of at least two seconds, the Electronic Control Module (ECM) evaluates the signal voltage from each pressure sensor. The ECM compares each signal voltage to a reference voltage. The reference voltage that is used depends on the sensor.If a signal voltage is close to the reference voltage, the ECM will internally adjust the signal voltage. The internal adjustment causes the pressure value for the sensor to be correct. This process is called automatic sensor calibration.If a signal voltage is not close to the reference voltage, the ECM will not internally adjust the signal voltage. The ECM will set a fault code that indicates there is a problem with the signal voltage.Table 1 indicates the maximum error that is permitted for each sensor, and the reference for that sensor. Refer to the troubleshooting procedure to determine the root cause of the incorrect signal voltage.
Table 1
Diagnostic Trouble Codes
CDL Code J1939 Code Code Description
(code descriptions may vary) Comments
100-13 100-13 Engine Oil Pressure Sensor : Out of Calibration During key on, the signal voltage from the engine oil pressure sensor indicated an engine oil pressure greater than +/- 54 kPa (8 psi) from the atmospheric pressure sensor.
Reference sensor : Atmospheric Pressure Sensor
274-13 108-13 Atmospheric Pressure Sensor : Out of Calibration During key on, the signal voltage from the atmospheric pressure sensor indicated an atmospheric pressure other than 0 kPa (0 psi).
This sensor is used as a reference sensor
460-13 411-13 Fuel Pressure Sensor - After Fuel Filter : Out of Calibration During key on, the signal voltage from the fuel outlet pressure sensor (after secondary fuel filter) indicated a pressure other than 0 kPa (0 psi) .
This sensor is used as a reference sensor
1785-13 3251-13 Intake Manifold Pressure Sensor : Out of Calibration During key on, the signal voltage from the Intake Manifold pressure sensor indicated an Intake Manifold pressure greater than +/- 18 kPa (3 psi) from the Atmospheric Pressure sensor.
Reference sensor : Atmospheric Pressure Sensor
Table 2
Troubleshooting Test Steps Values Results
1. Check for Diagnostic Trouble Codes
The engine coolant temperature must be greater than 0° C (32° F) before beginning this procedure.
A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM) . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
C. Wait at least 30 seconds in order for the diagnostic codes to become active.
Look for an active -13 code or for a logged -13 code.
Diagnostic Trouble Codes
Result: There is an active or there is a logged -13 code.
Proceed to Test Step 2.
2. Check for Debris
A. Turn the keyswitch to the OFF position.
B. Check the suspect sensor for debris.
C. If applicable, check the reference sensor for debris.
D. Check the sensor measurement port for blockage by debris.
E.