CLIP (SLOTTED BOLT HOLE) 4S4455 - Caterpillar

System Operation Description:The rotary position sensor provides a throttle signal to the engine's Electronic Control Module (ECM). The output for rated speed is a pulse width modulated signal (PWM) at a constant frequency. The throttle signal varies with the position of the rotary position sensor. The output signal is referred to as a duty cycle or as a Pulse Width Modulated signal (PWM). The output signal is expressed as a percentage between 0 and 100 percent for the speed adjust.The ECM calculates the desired engine rpm from the rated speed signal. The rated speed signal is valid when the duty cycle is in the range of 5 to 95 percent. If the ECM determines that the rated speed signal is invalid, the engine rpm will be set to the programmed low idle.Some applications may choose not to use the rotary position sensor. Some applications may use a load sharing module. The load sharing module is configured to provide the engine control with a rated speed signal. The signal has the same characteristics as the above defined signal. Some of these load sharing modules can not provide a signal until the engine is running. In these cases, troubleshooting should be performed while the engine is running.
Illustration 1 g01173277
Schematic
Illustration 2 g00766798
Percent of throttle position versus PWM input
Illustration 3 g01173295
P1 ECM connector
(P1-66) Primary speed signal
(P1-44) Droop-Isoch switch
(P1-68) Secondary speed signal Test Step 1. Check for Connector Damage.
Turn the keyswitch to the OFF position.
Thoroughly inspect the J61/P61 customer connector, the J1/P1 ECM connector, the J2/P2 ECM connector and any related connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the connectors.
Check each connectors (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasions and for pinch points from the battery to 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 and of pinch points.Results:
OK - The connectors and wiring are okay. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not okay.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the Supply Voltage to the Rotary Position Sensor
Connect one probe of a voltmeter to the +Battery terminal of the rotary position sensor. Connect one probe of the voltmeter to the −Battery terminal of the rotary position sensor.
Turn the keyswitch to the ON position.
Measure the battery