SUPPORT ASSEM. 1V3997 - Caterpillar

System Operation Description:Use this procedure under the following situation:Use this procedure to determine if the circuit for the torque limit switch is operating correctly.The following background information is related to this procedure:The Engine Control Module (ECM) can use various inputs in a number of ways. The inputs depend on the parameter programming. Certain features are available on several different inputs. The configuration for the switch must match the actual switch installation in order for the switch to function properly.Torque Limit SwitchThe torque limit switch provides a way to temporarily protect equipment from damage that is caused by applying too much torque. Torque limiting is typically used during PTO operation. Torque limiting can also be used when the PTO On/Off switch is in the OFF position.In order to use torque limiting, a "Torque Limit" must be programmed. The "Torque Limit" parameter is located under the "Dedicated PTO Parameters". The default setting is 3400 N m (2500 lb ft). The "Torque Limit Switch" input selection must also be programmed. If the "Torque Limit Switch" parameter is programmed to "None" (default), this feature is not used. If the "Torque Limit Switch" is programmed to J1/P1:7, then the feature is available and the torque limit switch should be connected to terminal 7 of the J1/P1 ECM vehicle harness connector.Note: The wiring for your particular application may be slightly different. The circuits for the sensor common are used interchangeably by the OEM of the vehicle. The following circuits are common within the ECM:
The "Input Sensor Common 1" is terminal 18.
The "Input Sensor Common 2" is terminal 3.
The "AP Sensor/Switch Sensor Common" is terminal 5.
Illustration 1 g00682363
Schematic for torque limit switch
Illustration 2 g01105866
Terminal locations for ECM
(P1-7) Input number 4 (Torque limit switch)
(P1-18) Input number 1 (Sensor common) Test Step 1. Inspect Electrical Connectors and Wiring
Thoroughly inspect the ECM vehicle harness connector J1/P1, the connectors, and the firewall bulkhead connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit for the torque limit switch. The wires are on the following terminals:
P1-7
P1-18
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and the wiring for abrasion and for pinch points from the battery to the ECM. Then, check from the ignition key switch to the ECM. Refer to Illustration 2 for terminal locations for the ECM.Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Status