ENGINE AR-PRIMARY 2540115 - Caterpillar

Possible Causes of an FMI 8 are:
The sensor has failed.
Intermittent connections or poor connections.
Incorrect software is loaded to the ECM.
Transmission system pressure loss.
The Transmission ECM has failed. An ECM failure is unlikely.
Illustration 1 g03541616
Transmission ECM Speed Sensors
Note: The diagram above is a simplified schematic of the Transmission ECM connections. These schematics are electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, UENR6727Diagnostic Trouble Code Procedure
Note: Prior to beginning this procedure, inspect the harness connectors that are involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.
Table 2
Sensor Description Resistance
(CID 585) Transmission Output Speed Sensor #1 1500 100 Ohms @ 25 °C (77 °F)
(CID 672) Torque Converter Output Speed Sensor 1500 100 Ohms @ 25 °C (77 °F)
(CID 673) Transmission Output Speed Sensor #2 1500 100 Ohms @ 25 °C (77 °F)
Table 3
Troubleshooting Test Steps Values Results
1. Identify The Active FMI Code Associated With Sensor Circuit
Code present FMI 8 diagnostic code proceed to Test Step 2.
Begin Process For FMI 8 Troubleshooting HERE
2. Check for Slip Event(s)
A. Check whether one or more Transmission Slip Detected events are active and BOTH Transmission Output Speed Sensor diagnostics are active.
One or more of EID 2201-2204 or E2301-2304 are active, and DTC 585 and DTC 673 are both active. OK - Both transmission output speed sensor diagnostics and transmission clutch slip event(s) are not all active at the same time.
Proceed to Test Step 3.
NOT OK - Both transmission output speed sensor diagnostics and transmission clutch slip event(s) are all active at the same time.
Repair: Proceed to the “Transmission Clutch Slips Troubleshooting Procedure” within Troubleshooting, "Transmission Clutch Slips" in this manual.
3. Verify The Software Version
A. Check and record the latest software version for the machine electronic controls from SIS.
B. Verify that the latest version of software has been loaded to the ECM.
All of the software is current. OK - All of the software is current.
Proceed to Test Step 4.
NOT OK - There is a more recent software release that is available.
Repair: Flash all controls with the latest software release. Refer to Troubleshooting, "ECM Software - Install".
STOP
4. Check The Resistance Of The Sensor
A. Remove the sensor from the machine harness. Insert a multimeter probe in contact 1 and contact 2 of the sensor.
B. Measure the resistance of the sensor.
The resistance is within the specifications in Table 2. OK - The resistance is within the resistance specifications in Table 2.
Proceed to Test Step 5.
NOT OK - The resistance is not within the resistance specifications in Table 2.
Repair: Replace the speed sensor.
STOP
5. Check For An Open In The Sensor Circuit
A.