WASHER 2N0828 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the sensors or if any one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
94-3 Fuel Delivery Pressure Sensor voltage above normal The Electronic Control Module (ECM) detects signal voltage that is above normal for eight seconds. The code is logged.
The value of the parameter is set to a gauge pressure of 600 kPa (87 psi).
94-4 Fuel Delivery Pressure Sensor voltage below normal The ECM detects signal voltage that is below normal for eight seconds.
100-3 Engine Oil Pressure Sensor voltage above normal The ECM detects signal voltage that is above normal for eight seconds. The code is logged.
The value of the parameter is set to a gauge pressure of 600 kPa (87 psi).
100-4 Engine Oil Pressure Sensor voltage below normal The ECM detects signal voltage that is below normal for eight second.
100-10 Engine Oil Pressure Sensor abnormal rate of change The signal voltage has not changed at a normal rate for thirty seconds.
Engine speed must be above 600 rpm.
274-3 Atmospheric Pressure Sensor voltage above normal The ECM detects signal voltage that is above normal for thirty seconds. The code is logged.
The value of the parameter is set to 100 kPa (14.5 psi).
274-4 Atmospheric Pressure Sensor voltage below normal The ECM detects signal voltage that is below normal for thirty seconds.
1785-3 Intake Manifold Pressure Sensor voltage above normal The ECM detects signal voltage that is above normal for two seconds. The code is logged.
The value of the parameter is set to a gauge pressure of 100 kPa (15 psi).
1785-4 Intake Manifold Pressure Sensor voltage below normal The ECM detects signal voltage that is below normal for two seconds.
1785-10 Intake Manifold Pressure Sensor abnormal rate of change The signal voltage has not changed at a normal rate for thirty seconds.
Engine speed must be above 1000 rpm. System OperationUse this procedure to troubleshoot any suspect problems with the following sensors:
Fuel pressure sensor
Engine oil pressure sensor
Atmospheric pressure sensor
Intake manifold pressure sensorThe supply voltage is routed to terminal A of each sensor connector. The sensor return is routed to terminal B of each sensor connector. The sensor signal is routed to terminal C of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.The ECM performs an automatic calibration of these sensors whenever the ECM is powered and the engine is off for at least five seconds. During an automatic calibration, the ECM calibrates pressure sensors to the value of the atmospheric pressure sensor and against an acceptable offset pressure range.The ECM continuously outputs a pull-up voltage on the input terminal from an analog sensor. The ECM uses this pull-up voltage in order to detect an open or a short in the signal circuit. When the ECM detects the presence of a voltage that is