PANEL AS 4669675 - Caterpillar

Machine ECM
The following is a list of diagnostic codes associated with the speed sensors of the machine.
Table 1
Machine ECM (MID 299)
DTC Code Description System Response
190-8 Engine Speed Sensor : Abnormal Frequency, Pulse Width, or Period This code is activated when the ECM discovers disagreement with the transmission input speed sensor.
The code is recorded when the signal of the engine speed sensor is below the dropout value and the engine speed is above low idle. Possible Causes for an FMI 8 diagnostic code are:
The sensor has failed.
Intermittent connections or poor connections.
Mechanical devices are loose.
Incorrect software is loaded to the ECM.
The ECM has failed. ECM failure is unlikely.
Illustration 1 g03703712
Illustration of the connections for the Engine Speed Sensor
Note: The diagram above is simplified schematic of the Machine ECM connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, UENR5948. Diagnostic Troubleshooting Procedure
Note: Poor harness connections are often the cause of a problem in electrical circuits. Before performing any troubleshooting procedure, inspect all of the connectors involved in the circuit. Verify that all of the connections in the circuit are dry, clean, secure, and in good condition. Each pin and socket in the connectors should mate correctly when the connectors are fastened together. Check for exposed wires at the connectors for nicks or abrasion. If a problem is found with any of the connections: correct the problem and verify that the diagnostic code is still active, before performing the following procedures. For more information, refer to Troubleshooting, "Electrical Connector - Inspect".
Table 2
Troubleshooting Test Steps Values Results
1. Identify Active DTC Code Associated With Sensor Circuit
Code present FMI 8 diagnostic code, proceed to Test Step 2.
Begin Process For FMI 8 Troubleshooting HERE
2. Inspect The Harness Connectors
A. Turn the disconnect switch and the key start switch to the OFF position.
B. Inspect all harness connections related to the sensor. Make sure that the connectors are clean and tight.
C. Check the connectors for proper mating. Ensure that all the seals are present and in place.
D. Check the harness for signs of damage or abrasion.
E. Check the wires at the connector. Ensure that the wires are secured tightly into the connector.
F. Perform a 45 N (10 lb) pull test on each of the wires associated with the circuit. Take care not to pull the wire out of the connector.
G. Check the exposed wires at the connectors for nicks or signs of abrasion.
H. Check the connectors for moisture, dirt, or corrosion.
The machine harness connectors are tight and free of corrosion. OK - The machine harness connectors are tight and free of corrosion.
Proceed to Test Step 3.
NOT OK - The machine harness connectors are in need of repair.
Repair: Repair the machine harness or replace the machine harness.
STOP
3. Check The Circuit For An Open
A. Turn the disconnect switch and the key start switch to the OFF position.
B. Disconnect the machine harness from the sensor.
C. At the machine harness connector for the sensor, install a jumper wire between