WASHER-SPECIAL 2539818 - Caterpillar

Test Step 1. CHECK THE RESISTANCE OF THE DATA LINK CIRCUIT
Illustration 4 g01948283
CAN terminal resistors at the Engine ECM harness
(6) Engine system local CAN terminal resistor
(7) J1939 Global CAN A terminal resistor
Illustration 5 g01961234
J1939 Global CAN A terminal resistor (view: right side of Engine, looking forward in the electronic thermostat harness)
Note: Two 120 ohm data link terminating resistors are connected in parallel in the data link circuit. One of the terminating resistors is connected with a "Y connector" that is located forward of the electronic thermostat in the harness. The other terminating resistor is located in the engine harness that is close to the Engine ECM connectors. When the resistance of the circuit is measured with both resistors connected across the circuits, the measurement should be approximately 60 ohms.
Turn the key switch and the battery disconnect switch to the OFF position.
At the Drivetrain ECM, disconnect the machine harness connector J2. Check the condition of the harness connector contacts and the ECM connector contacts. Ensure that all of the pins and sockets are secured in the connector, the contacts are clean, and the contacts are in good condition.
At the Brake ECM, disconnect the machine harness connector J2. Check the condition of the harness connector contacts and the ECM connector contacts. Ensure that all of the pins and sockets are secured in the connector, the contacts are clean, and the contacts are in good condition. Note: The Drivetrain ECM is connected to the CAN A data link system in series with the Engine ECM, the Chassis ECM, and the Brake ECM. In the next step, the resistance of the system will be checked toward one terminal resistor from the Drivetrain ECM. Resistance will also be checked toward the other terminal resistor from the Brake ECM. These checks will isolate one terminal resistor in each measurement. Refer to the connection diagram at the beginning of this procedure for clarification.
At the harness connector J2 for the Drivetrain ECM, measure the resistance between CAN A high contact J2-56 (wire Y956-YL(Yellow)) and CAN A low contact J2-70 wire Y957-GN(Green)).
At the harness connector J2 for the Brake ECM, measure the resistance between CAN A high contact J2-56 (wire Y956-YL(Yellow)) and CAN A low contact J2-70 wire Y957-GN(Green)). Expected Result:Each of the resistance measurements is