PANEL AS 4645028 - Caterpillar

Illustration 1 g01260467
Schematic of the Transmission Output Speed SensorThis diagnostic code is associated with the transmission output speed sensor. This diagnostic code is recorded when the ECM reads the signal from the sensor and the ECM determines that the signal is erratic, intermittent, or incorrect.The possible causes of this diagnostic code are listed:
Wire (E901-GN) is shorted to the ground circuit while the machine is in operation.
Wire (E901-GN) is shorted to the +battery.
An open circuit exists.
The ECM has failed. This is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0191 FMI 02 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.
Table 1
Type     Low Range     High Range    
Sensor 1     75 ohms at
−40 °C (−40 °F)     230 ohms at
120 °C (248 °F)    
Sensor 2     600 ohms at
−40 °C (−40 °F)     1800 ohms at
120 °C (248 °F)    Note: There are two types of speed sensors that can be used in this application. The following test steps state the values that are for the second speed sensor. Determine the speed sensor on the machine. Make sure that the sensor has failed before replacing the sensor.System Response:When the CID 0191 FMI 02 diagnostic code is active. Machine response will be:
The transmission will only operate in first gear.
Machine functions will be limited.Note: Before performing the following Test Steps, check to see that the speed sensor is mounted securely. If the speed sensor mount is correct and the CID 0191 FMI 02 code is active, proceed to Test Step 1.Test Step 1. INSPECT THE HARNESS CONNECTIONS.
Turn the disconnect switch to the OFF position.
Inspect all harness connections that are related to the sensor. Make sure that the connectors are clean and tight.
Check the connectors for proper mating. Ensure that all the seals are present and in place.
Check the harness for signs of damage or abrasion.
Check the wires at the connector. Ensure that the wires are secured tightly into the connector.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit. Take care not to pull the wire out of the connector.
Check the exposed wires at the connectors for nicks or signs of abrasion.
Check for moisture inside the connector.
Check the connectors for dirty contacts or corroded contacts.
Check each pin and each socket of the machine harness connectors. Ensure that the contacts are properly installed. The contacts should mate correctly when the two pieces of the connector are placed together.Expected Result:The machine harness connectors are tight and free of corrosion.Results:
OK - The machine harness connectors are tight and free of corrosion. Proceed to test step 2.
NOT OK - The machine harness connectors are in need of repair.Repair: Repair the machine harness or replace the machine harness. STOPTest Step 2. CHECK THE CIRCUIT FOR AN OPEN.
Turn the