VALVE GP 5I4087 - Caterpillar

Illustration 1 g01392054
Schematic for the Drive Motor Speed Sensor
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Drive Motor Speed Sensor locationThe drive motor has a speed sensor which delivers two separate signals in order to determine speed and direction of rotation. This diagnostic code is associated with the Drive Motor Speed Sensor signal #2. The ECM is able to diagnose each signal wire independently. Each signal wire provides a frequency input to the ECM that is proportional to motor speed. If this diagnostic code is active, the ECM will keep the code active until a good sensor signal is observed by the ECM. This means that the drive motor must be moved in order for the ECM to determine if the active code can be cleared.This diagnostic code is recorded when the machine ECM receives an incorrect signal from the motor speed sensor. The incorrect signal that is being read by the machine ECM has the following characteristics: Abnormal frequency, pulse width, or periodThe possible causes of this diagnostic code are listed:
The supply circuit is open.
The return circuit is open.
The signal circuit is open.
The signal circuit is shorted.
The sensor has failed.
The ECM has failed. ECM failure is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections are clean. Verify that connections are secure. Verify that all connections are in good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.System Response:CID 2776 - FMI 08 will generate a level 2 warning. "Unexpected Motor Speed Detection Control" will be disabled. While the machine is moving, a level 3 event will be active indicating that "Unexpected Motor Speed Detection" is disabled. Event Code E695 will indicate this event.Note: The following test procedure may create other diagnostic codes. Clear the diagnostic codes when the problem has been corrected. Verify that CID 2776 - FMI 08 is active before performing this procedure.Test Step 1. CHECK THE POWER AT THE SENSOR
The machine harness remains disconnected from the sensor.
Turn the key start switch to the ON position.
At the machine harness for the sensor, measure the voltage. Measure the voltage from contact 1 (wire 497-BU) and contact 2 (wire J765-BU).Expected Result:The voltage that is measured is 8.0 5 VDC. Results:
OK - The voltage measurement is 8.0 0.5 VDC. Proceed to Test Step 2.
NOT OK - The measurement is not correct.Repair: Repair the harness or replace the harness. Verify that the diagnostic has been cleared. Drive the machine above the speed threshold. Verify that the diagnostic tool has been cleared. STOPTest Step 2. CHECK FOR AN OPEN SIGNAL CIRCUIT
Turn the Disconnect switch and the Key Start switch to the OFF position.
Remove the J1 and J2 connectors from the ECM.
Place a jumper between pins J2-33 (wire E901-GN) and J2-34 (wire E902-PU).
Disconnect the speed sensor from the machine harness. Measure the continuity between pins 3 and 4