ROD AS 2478962 - Caterpillar

Illustration 3 g01826773
Machine harness connector contacts for the speed sensors
At the Right Front Wheel Speed Sensor, disconnect the machine harness connector from the sensor connector. Use a multimeter to measure the resistance between the power supply contact 1 (wire K477-GN) and the return contact 2 (wire K476-YL).
While observing the resistance measurement, wiggle the machine harness connector for the speed sensor. If possible, while observing the resistance measurement, have someone wiggle the harness connector J1 at the Drivetrain ECM. Gently pull on the wires and move the wires around. Do not disconnect the jumper wire.
At the Drivetrain ECM, remove the jumper wire from the J1 harness connector contacts. At the J2 harness connector, connect the jumper wire between the signal A contact J2-42 (wire K481-GY) and the signal B contact J2-43 (wire K482-OR). Ensure that the jumper wire is making good contact with both of the signal contacts.
At the harness connector for the speed sensor, use a multimeter to measure the resistance between the signal A contact 3 (wire K481-GY) and the signal B contact 4 (wire K482-OR).
While observing the resistance measurement, wiggle the machine harness connector for the speed sensor. If possible, while observing the resistance measurement, have someone wiggle the harness connector J2 at the Drivetrain ECM. Gently pull on the wires and move the wires around. Do not disconnect the jumper wire.Expected Result:Each resistance measurement is less than 5 ohms at all times during the manipulation of the harness and the connectors.Results:
OK - The resistance measurements are less than 5 ohms. The resistance measurements for the speed sensor circuits are not indicating that there is an open circuit or a poor connection in any of the speed sensor circuits between the ECM and the speed sensor. Proceed to Test Step 3.
NOT OK - One or both of the resistance measurements is greater than 5 ohms at all times or the resistance measurement is greater than 5 ohms part of the time during the manipulation of the circuit wiring. There is an open circuit or a poor connection in one of the speed sensor circuits.Repair: Check each of the circuits that measured the high resistance individually in order to determine which circuit has the open or the poor connection.A resistance measurement that is greater than 5 ohms but less than 5000 ohms could indicate that one of the connection points in the circuit is not open but is not a good connection. A resistance measurement that is greater than 5000 ohms could indicate that a wire is either not connected or is open. For complete machine harness and connector information in the circuits between the Drivetrain ECM and the speed sensor on the front axle housing, refer to the complete machine Electrical System Schematic. Locate and examine all of the circuit connections that are used in the suspected sections of the speed sensor circuit. Check each wire section from connector to connector for an open or a bad connection. Ensure that all connections are clean, secure, and in