SHAFT ASSEMBLY 3N1211 - Caterpillar

start switch to the OFF position.
At the Drivetrain ECM, use the spoon type 7X-1710 Multimeter Probes to check the duty cycle of the diagnostic feedback circuit. Insert the positive probe along the feedback circuit wire at connector contact J2-34 (wire E857-GN) and insert the negative probe along the return circuit wire at contact J1-60 (wire E858-YL).
Turn the battery disconnect switch and the key start switch to the ON position.
Check the duty cycle of the diagnostic feedback circuit at the ECM connectors.
While observing the duty cycle measurement, wiggle the machine wiring harness close to the Drivetrain ECM connectors. Follow the harness back to the ECM compartment connectors while wiggling the harness.
On the outside of the cab, locate the round EF-C1 connector that is used to pass the EFR circuit connections through the cab wall. While observing the duty cycle measurement, wiggle the harness coming out of the cab.Expected Result:The duty cycle of the feedback circuit remains at 10 percent at all times while the wiring harness is manipulated.Results:
YES - The duty cycle of the feedback signal is steady at 10 percent at all times during the manipulation of the harness. The feedback signal is correct. Proceed to Test Step 3.
NO - The duty cycle of the feedback signal is not at 10 percent at any time or the duty cycle is not steady at 10 percent during the manipulation of the harness. There is a problem in the diagnostic feedback circuit or in the EFR. Proceed to Test Step 2.Test Step 2. CHECK THE DIAGNOSTIC FEEDBACK CIRCUIT FOR A SHORT TO GROUNDThe key start switch and the disconnect switch remain in the OFF position.The 14 contact control circuit harness connector remains disconnected from the EFR.
At the Drivetrain ECM, disconnect the J1 and the J2 harness connectors. Visually check each of the connector contacts for damage or contamination. Verify that the contacts are clean, secured in the connector and in good condition.
At the J2 machine harness connector for the Drivetrain ECM, measure the resistance between the diagnostic feedback signal contact J2-34 (wire E857-GN) and a good frame ground point. Measure the resistance between the diagnostic feedback signal contact J2-34 and each individual connector contact that is used in the J1 and J2 connectors for the Drivetrain ECM.Expected Result:Each individual resistance measurement is greater than 4000 ohms.Results:
OK - Each individual resistance measurement is greater than 4000 ohms. The feedback circuit resistance checks do not indicate a short circuit to frame ground or to another circuit in the machine harness. Proceed to Test Step 3.
NOT OK - One or more of the resistance measurements is less than 4000 ohms. There is a short circuit in the machine harness between the diagnostic feedback circuit and either frame ground or to another circuit in the machine harness.Repair: Refer to the complete machine Electrical System Schematic. Check all of the connectors that are in the circuit. Ensure that all connections are clean, secure, and in good condition.Check the harness for areas where contact with the