WIRE 5P5620 - Caterpillar

Table 2
FMI 2 Troubleshooting
Troubleshooting Test Steps Values Results
1. Check The Resistance Of The Sensor
A. Turn the key start switch and the disconnect switch to the OFF position.
B. Disconnect the speed sensor from the machine harness.
C. Measure the resistance between contacts 1 and 2 of the connector for the speed sensor.
D. Refer to the table above for the correct resistance values.
The resistance values for the speed sensors are correct according to the table above. OK - The resistance of the speed sensor is within the expected range.
Proceed to Test Step 2.
NOT OK - The resistance of the speed sensor is outside the expected range. The speed sensor has failed.
Repair- Replace the speed sensor.
Proceed to Test Step 4.
2. Check The Signal Circuit For An Open
A. The key start switch and the disconnect switch remain in the OFF position.
B. Disconnect the speed sensor from the machine harness.
C. Disconnect the machine harness connectors from the ECM.
D. At the speed sensor harness connector, insert a jumper wire between the signal and return wires.
E. At the ECM harness connector, measure the resistance between the signal contact and the return contact.
The resistance value is less than 5 Ω. OK - The resistance value is less than 5 Ω. The harness is correct.
Proceed to Test Step 3.
NOT OK - The resistance is greater than 5K Ω. There is an open circuit in the signal circuit or the return circuit.
Note: A resistance greater than 5 Ω but less than 5KΩ indicates a loose connection or corroded connection in the circuit. A resistance value that is greater than 5K Ω would indicate an open in the circuit.
Repair: Repair or replace the machine harness.
Proceed to Test Step 4.
3. Check The Signal For A Short
A. Remove the jumper wire that was installed in the previous test step.
B. Reconnect the speed sensor to the machine harness.
C. At the ECM machine harness connectors, measure the resistance between the signal contact and all the other contacts that are used for the ECM.
D. At the ECM machine harness connectors, measure the resistance between the return contact and all the other contacts that are used for the ECM.
Each resistance value is greater than 5K Ω OK - Each resistance value is greater than 5K Ω
Proceed to Test Step 4.
NOT OK - A resistance value is less than 5 Ω. There is a short in the machine harness. The short is between the signal circuit or the return circuit and the circuit with low resistance.
Repair: Repair or replace the machine harness.
Proceed to Test Step 4.
4. Check If The Diagnostic Code Remains
A. Reconnect all harness connectors. Return machine to normal operating condition.
B. Turn the key start switch and the disconnect switch ON.
C. Clear all diagnostic codes.
D. Operate the machine.
E. Stop the machine and engage the safety lock.
F. Check if the diagnostic code is active.
The diagnostic code is no longer present. OK - The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by poor electrical connection or short at one