FILTER ELEMENT AS-CAB AIR 1454088 - Caterpillar

System Operation Description:The fuel position multiplier is an external input to the Electronic Control Module (ECM). The input reduces the available fuel rack according to the magnitude of the signal. The fuel position multiplier can be considered as an external derating of engine power. Typically, the input is a means for reducing the engine power without changing the throttle signal.The ECM reads a Pulse Width Modulated signal (PWM) that is similar to the throttle signal. Usually, a converter is used to change the signal from the torque limit control into a PWM signal. An increase in the duty cycle reduces the available fuel. For example, if the engine power output is 100 percent and the signal from the fuel position multiplier is 75 percent, the engine power output is reduced to 25 percent. The fuel position multiplier affects the available fuel rack instantly. The signal is applied in addition to any active derating of the engine power. For example, if the engine is presently derated by 10 percent due to high exhaust temperature and the signal from the fuel position multiplier is 25 percent, the engine power output is reduced by a total of 35 percent. A signal of 10 percent or less will dictate the multiplier to 1.0 (100 percent). A signal of 90 percent to 95 percent will dictate the multiplier to 0.0 (0 percent). A signal of 95 percent or a signal that is greater than 95 percent will dictate the multiplier to 1.0 (100 percent).
Illustration 1 g00821218
Test Step 1. Check for Connector Damage.
Turn the engine control to the OFF position.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" 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.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring should be free of corrosion, abrasion or pinch points.Results:
OK - The wiring and connectors are okay. Proceed to test step 2.
Not OK - The wiring and connectors are not okay.Repair: Repair the connector and/or wiring or replace the connector and/or wiring.STOPTest Step 2. Check the Fuel Position Multiplier.
Turn the engine control to the OFF position.
Disconnect the customer supplied fuel position multiplier.
Connect a throttle position sensor or a device that will generate a 500 Hz PWM signal. Connect the attachment directly to the wiring that sends the PWM signal to the ECM.Note: Remember to remove the sensor and the attachment for the throttle when the test is complete. Reconnect the Fuel Position Multiplier.
Start the Caterpillar Electronic Technician (ET).
Turn the engine control to the ON position.
Observe the fuel position