GLASS-DOOR 5051120 - Caterpillar

Illustration 1 g00755062
Schematic of the speed sensor (Transmission Output)This diagnostic code is recorded when the ECM reads the signal of the speed sensor as being out of range.Note: This diagnostic code is usually an intermittent condition. The diagnostic code can be active or the diagnostic code can be not active.The possible causes of this condition are listed:
The signal circuit is intermittently shorted to the + battery circuit or shorted to ground.
The sensor has failed.Note: The following diagnostic code procedure can create other related diagnostic codes. Perform the following procedure. Reconnect all harnesses. Then clear all the related diagnostic codes.Note: The engine must be running in order for this diagnostic code to be active.Test Step 1. CHECK THE SENSOR.
Turn the disconnect switch and the key start switch to the ON position.
Ensure that the diagnostic code is active.
Disconnect the sensor from the machine harness.Expected Result:The diagnostic code is NO longer active.Results:
YES - The diagnostic code is NO longer active.Repair: The sensor has failed. Replace the sensor. Verify that the new sensor corrects the problem. The diagnostic code should NO longer be active. Stop.
NO - The diagnostic code remains active. The sensor is not the cause of the diagnostic code. Proceed to test step 2.Test Step 2. CHECK FOR A SHORT IN THE MACHINE HARNESS.
The sensor remains disconnected from the machine harness.
Turn the key start switch to the OFF position.
Disconnect the harness connector from the transmission ECM.
At the harness connector for the ECM, measure the resistance between the signal contact 5 (wire 710-GN-18) to all other contacts of the harness connector.Expected Result:Each resistance measurement should be greater than 5000 ohms.Results:
YES - Each resistance measurement is greater than 5000 ohms. The harness is correct.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this diagnostic code procedure again. If the cause of the diagnostic code is not found, replace the transmission ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". Stop.
NO - The resistance measurement is not greater than 5000 ohms for all measurements.Repair: The machine harness has failed. There is a short in the machine harness. The short is between contact 5 and the circuit with the low resistance measurement. Repair the machine harness or replace the machine harness. Stop.