BLOCK-TERMINAL 5311105 - Caterpillar

Illustration 1 g03747317
Connections of the Front Drum Vibratory Speed Sensor #2
This diagnostic code is associated with the Front Drum Vibratory Speed Sensor #2. The FMI 02 means that the ECM has detected that signal is Erratic, Intermittent, or Incorrect.Note: Diagnostic Codes for components of the Front AAC Controller are relayed to the Machine ECM via the CAN Data Link. The possible causes of this failure are listed below:
The sensor has failed.
The Power to the sensor has failed.
The signal circuit of the sensor is shorted to ground.
The sensor circuit has an open.
Speed is greater than 45 Hz in Low Frequency.
Speed is greater than 58 Hz in High Frequency.
Speed Signal is less than 10 Hz if Machine Vibe Speed is greater than 35 Hz.
The ECM has failed. This situation is unlikely.Note: 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 in the circuit are clean and secure. Verify that all connections in the circuit 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. After making any possible fix to the circuit, cycle the Key Switch in order to determine if the Diagnostic Code still exists. Some Diagnostic Codes may not display until the engine is running. Verify that the CID 4583 FMI 02 is active before performing this procedure.Use a digital multimeter for the measurements in this procedure.System Response:A Level 2 Warning is generated.Test Step 1. INSPECT THE SENSOR
Perform a visual inspection of the sensor, the wiring for the sensor and the hardware that is associated with the sensor. Note: The Front and Rear Vibratory Speed Sensors are identical. The sensors may be swapped to validate the failed part.Expected Result:There is no apparent damage to the sensor, the wiring for the sensor or the hardware that is associated with the sensor.Results:
YES - There is no apparent damage to the sensor, the wiring for the sensor or the hardware that is associated with the sensor. Proceed to Test Step 2.
NO - There is apparent damage to the sensor, the wiring for the sensor or the hardware that is associated with the sensor. Repair: Replace the damaged part.STOPTest Step 2. CHECK FOR POWER AT THE SENSOR
Disconnect the sensor from the machine harness.
Turn the key start switch and the disconnect switch to the ON position.
At the harness connector for the sensor, measure the voltage from contact 1 (wire K424-GN(Green)) to frame ground. Expected Result:The voltage is 8 1.0 VDC.Results:
YES - The voltage is 8 1.0 VDC. Proceed to Test Step 3.
NO - The voltage is not 8 1.0 VDC. The circuit is open. Repair: Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK THE SENSOR CIRCUIT FOR AN OPEN CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the