SUPPORT AS 2263949 - Caterpillar

Table 1
Diagnostic Codes Table
J1939 Code CDL Code Code Description Comments
1639-17 E1363 (1) Low Engine Cooling Fan Speed The code is logged.
N/A 544-2 Engine Cooling Fan Speed Sensor : Erratic, Intermittent, or Incorrect The code is logged.
N/A 544-8 Engine Cooling Fan Speed Sensor : Abnormal Frequency, Pulse Width, or Period The code is logged. The engine cooling fan speed sensor provides a signal to the Electronic Control Module (ECM). The ECM controls fan speed by varying the current to the fan control solenoid.The engine cooling fan speed sensor receives a supply voltage of 5.0 0.5 VDC from the ECM. The sensor outputs a frequency that is directly proportional to fan speed. The sensor generates a signal pulse for each revolution of the fan. The output frequency varies between 5 Hz to 180 Hz over the speed range between 50 rpm and 1800 rpm.
Illustration 1 g03011039
Schematic for the fan speed sensor "3 Pin Connector"
Illustration 2 g06124085
Schematic for the fan speed sensor "6 Pin Connector"
Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Values Results
1. Check the Status of the Engine Fan Speed
A. Turn the keyswitch to the OFF position.
B. Connect Cat® Electronic Technician (ET) to the service tool connector.
C. Turn the keyswitch to the ON position.
D. Access the "Fan Override Test" under the "Diagnostics" menu.
E. Start the "Fan Override Test" on Cat ET. Set the fan speed to