SENDER AS-TEMPERATURE 4W9972 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with a supply circuit 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
41-3 8 Volt DC Supply voltage above normal The digital sensor supply voltage is above normal for one second.
The Electronic Control Module (ECM) has been powered for three seconds. The code is logged.
All sensors are set to default values.
41-4 8 Volt DC Supply voltage below normal The digital sensor supply voltage is below normal for one second.
The ECM has been powered for three seconds.
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. The code is logged.
The value of the parameter is set to a gauge pressure of 600 kPa (87 psi).
262-3 5 Volt Sensor DC Power Supply voltage above normal The analog sensor supply voltage is above normal for one second.
The ECM has been powered for three seconds. The code is logged.
All sensors are set to default values.
262-4 5 Volt Sensor DC Power Supply voltage below normal The analog sensor supply voltage is below normal for one second.
The ECM has been powered for three 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. The code is logged.
The value of the parameter will be set to 100 kPa (15 psi). System OperationThe ECM supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Engine oil pressure sensor
Fuel pressure sensor
Intake manifold pressure sensor
Transmission oil pressure sensor
Transmission oil temperature sensorThe ECM supplies a regulated voltage of 8.0 0.4 VDC to the following sensors:
Coolant level sensor
Coolant level sensor for the aftercooler
Left exhaust temperature sensor
Right exhaust temperature sensorThe supply voltage for the sensors is routed from the ECM to terminal A of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal B 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.If a -10 code is logged, this indicates that the 5 volt supply is not available at the sensor connector. During normal engine operation, each of the signals from the pressure sensors fluctuate slightly. When the 5 volt supply becomes unavailable at the pressure sensor connector, the signal from that sensor floats to a midrange value. The signal will not fluctuate. If the signal from the sensor remains abnormally steady for more than 30 seconds, the ECM will activate this code.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If any of the 3 diagnostic codes are active, it is possible that a sensor has been damaged. Repair the sensor