 | |
| Illustration 1 | g02623975 |
Connections for the transmission speed sensor 1. | |
This diagnostic code is associated with the transmission speed sensor 1.
This diagnostic code is recorded when the ECM compares the signal from transmission speed sensor 1 to the signal from transmission speed sensor 2. The ECM will issue this diagnostic code if the data from the sensors is not within certain parameters.
The transmission speed sensors are mounted by a fixed mounting arrangement. When the sensor is mounted securely, no adjustment is necessary.
Sensor conditions that can cause this diagnostic code
- The signal circuit is shorted in the machine harness.
- The supply circuit is shorted in the machine harness.
- The speed sensor has failed.
- ECM failure is unlikely.
Note: Check for a secure mounting of the speed sensor before proceeding to test steps. If the speed sensor mount is secure and the CID 0585 FMI 02 code is active, proceed to Test Step 1.
Test Step 1. CHECK THE RESISTANCE OF THE SENSOR
- Turn the key start switch and the disconnect switch to the OFF position.
- Disconnect the machine harness connector from the sensor.
- Measure the resistance from contact 1 to contact 2 at the sensor connector.
Expected Result:
600 to 1800 ohms is an expected reading.
Results:
- OK - The resistance is within the acceptable range. Proceed to Test Step 2.
- NOT OK - The resistance is NOT within an acceptable range. The speed sensor is faulty.
Repair: The speed sensor has failed. Replace the speed sensor. Verify that the new sensor corrects the problem.
STOP
Test Step 2. CHECK FOR AN OPEN WIRE IN THE MACHINE HARNESS
- The key start switch and the disconnect switch remain in the OFF position.
- Disconnect the machine harness connector J1 from the ECM.
- At the disconnected machine harness connector for the sensor, connect a jumper between contact 1 and contact 2.
- Measure the resistance, at the machine harness connector between contact J1-2 (wire E900-WH) and contact J1-3 (wire E901-GN).
Expected Result:
The resistance is less than 5 ohms.
Results:
- OK - The resistance measurement is less than 5 ohms. The circuit is not open. Proceed to Test Step 3.
- NOT OK - The resistance measurement is more than 5 ohms. The circuit is open in the machine harness or there is a faulty connection in the machine harness.
Repair: Consult the complete electrical system schematic for this machine. Check all harness connectors that are in the speed sensor circuit. Ensure that the contacts of the connectors are clean, connected, and secure. After checking the connectors, repeat this test step. If the problem remains, check the circuit for a broken wire. Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK FOR A SHORT IN THE SENSOR CIRCUIT OF THE MACHINE HARNESS
Note: The machine harness connectors remain disconnected from the sensor and the ECM. Remove the jumper that was installed in the last step.
- The key start switch and the disconnect switch remain in the OFF position.
- At the machine harness connector for the ECM, measure the resistance between contacts J1-2 (wire E900-WH) and all contacts in the machine harness for the ECM.
- At the machine harness connector for the ECM, measure the resistance between contacts J1-3 (wire E901-GN) and all contacts in the machine harness for the ECM.
Expected Result:
Each resistance measurement is greater than 5000 ohms.
Results:
- OK - Each resistance measurement is greater than 5000 ohms. A short is not present in the machine harness. An intermittent short could be causing the problem. Proceed to Test Step 4.
- NOT OK - One or more of the measurements is less than 5000 ohms. There is a short in the machine harness. The short is between the sensor circuit and the circuit with the low resistance measurement.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 4. CHECK THE STATUS OF THE DIAGNOSTIC CODE
- Clean the contacts of the harness connectors.
- Reconnect all harness connectors.
- Turn the key start switch to the ON position.
- Clear all inactive diagnostic codes.
- Start the engine and drive the machine for a minimum of 10 seconds.
- Determine if the CID 0585 FMI 02 diagnostic code is active.
Expected Result:
The CID 0585 FMI 02 diagnostic code is active.
Results:
- YES - CID 0585 FMI 02 diagnostic code is active.
Repair: Check the wires in the machine harness again. Perform the Wiggle Test with the use of the Caterpillar Electronic Technician (ET) service tool. The wiggle test can detect momentary shorts, intermittent shorts or opens in the machine wiring harness.If the diagnostic code is still active and the cause cannot be found, replace the speed sensor. If the new speed sensor does not correct the problem, the ECM may be faulty.Prior to replacing an ECM, always contact the dealerships Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, replace the ECM. Refer to Troubleshooting, "Electronic Control Module (ECM) - Replace".
STOP
- NO - CID 0585 FMI 02 diagnostic code is not present.
Repair: The problem does not exist at this time. The initial problem was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.
STOP