This diagnostic code is for the sensor supply of the transmission oil temperature sensor or the steering oil temperature sensor. Both sensors are never present on the same machine. Refer to the Electrical System Schematic for the machine that is being serviced in order to determine the sensor that is on the machine.
This diagnostic code is recorded when the ECM reads the voltage of the sensor supply circuit (R800-OR) as above normal range. The transmission oil temperature sensor or the steering oil temperature sensor will not operate. The transmission may not shift smoothly when the transmission oil is cold (medium tractors). The top brake pressure will be reduced. The pressure is closer to the pressure that is used for the calibration of the brakes. The brakes may drag lightly.
The possible causes of this diagnostic code are listed below:
- The supply circuit (R800-OR) to the sensor is shorted to the +battery.
- The ECM has failed. This is unlikely.
Note: Ensure that the CID 0269 FMI 03 is on hold and that the diagnostic code indicator shows "SERV CODE".
Test Step 1. CHECK THE SUPPLY CIRCUIT FOR A SHORT TO THE + BATTERY.
- Turn the key start switch to the OFF position.
- Disconnect the machine harness (J1 and J2) from the ECM.
- At machine harness connectors for the ECM, measure the resistance from J2-44 to J1-1 and J1-31.
Expected Result:
The resistance should be greater than 5000 ohms for each measurement.
Results:
- OK - The resistance is greater than 5000 ohms for each measurement. The machine harness is correct. Proceed to Test Step 2.
- NOT OK - The resistance is not greater than 5000 ohms for each measurement.
Repair: The short is between the circuit with the low resistance measurement and wire R800-OR. Repair the machine harness or replace the machine harness.
STOP
Test Step 2. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE.
- Clean the contacts of the harness connectors.
- Reconnect all harness connectors.
- Turn the key start switch to the ON position.
- Enter service mode of the Caterpillar Monitoring System and clear all inactive diagnostic codes.
- Operate the machine.
- Determine if CID 0269 FMI 03 is present.
Expected Result:
The CID 0269 FMI 03 is active.
Results:
- YES - The CID 0269 FMI 03 is active. The problem has not been corrected.
Repair: Check the circuit again. If the Caterpillar Electronic Technician (ET) is available, use the Cat ET service tool in order to perform a "Wiggle Test" on the machine wiring harness. The "Wiggle Test" can detect shorts and opens in the machine wiring harness that are momentary or intermittent. It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. Prior to replacing an ECM, always contact your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP
- NO - The CID 0269 FMI 03 is not active. The problem does not exist at this time.
Repair: The initial diagnostic code 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