953C, 963C and 973C Track-Type Loaders Transmission Electronic Control System Caterpillar

This diagnostic code is recorded when the ECM reads an abnormal frequency from the engine speed sensor.

Note: The engine must be running to show that this diagnostic code is present. When the engine runs, the engine speed signal is received from the sensor or the charge pressure is above approximately 800 kPa (116 psi). If the diagnostic code is present, "SERV CODE" is showing.

The possible causes of this diagnostic code are listed below:

• The machine harness is shorted or the harness is open.

• The sensor has failed.

• The ECM has failed. This is unlikely.

System Response:

The results of this diagnostic code are listed below:

• A warning (Category 1) is shown on the monitor.

• The underspeed function will not operate. The engine may lug excessively during a normal loading cycle. The engine may stall during a normal loading cycle. The capability for travel speed of the machine will be reduced.

Test Step 1. CHECK THE CASE OF THE SENSOR .

1. Turn the key start switch to the OFF position.

2. Disconnect the machine harness from the speed sensor.

3. At the sensor, measure the resistance from contact 1 (wire L913-OR(Orange)) and from contact 2 (wire L912-WH(White)) to the case of the sensor.

Expected Result:

The resistance should be greater than 10000 ohms.

Results:

• OK - The resistance of the case is correct. Proceed to test step 2.

• NOT OK - The resistance of the case is not correct.

  Repair: The speed sensor has failed. Replace the sensor. Adjust the speed sensor properly when you install the sensor. See Testing and Adjusting, "Speed Sensor - Adjust". Verify that the new sensor corrects the problem.

  STOP

Test Step 2. CHECK THE SENSOR.

1. The key start switch remains in the OFF position. The sensor remains disconnected from the machine harness.

2. At the sensor, measure the resistance between contact 1 (wire L913-OR(Orange)) and contact 2 (wire L912-WH(White)).

Expected Result:

The resistance should be between 110 and 200 ohms.

Results:

• OK - The sensor resistance is correct. Proceed to test step 3.

• NOT OK - The sensor resistance is not correct.

  Repair: The speed sensor is failed. Replace the sensor. Adjust the speed sensor properly when you are installing the sensor. See Testing and Adjusting, "Speed Sensor - Adjust". Verify that the new sensor corrects the problem.

  STOP

Test Step 3. CHECK THE HARNESS FOR AN OPEN.

1. The key start switch remains in the OFF position.

2. Reconnect the machine harness to the sensor.

3. Disconnect the machine harness connectors J2 and J1 from the ECM.

4. At the machine harness connector J2, measure the resistance from contact J2-38 (wire L912-WH(White)) to contact J1-16 (L913-OR(Orange)).

Expected Result:

The resistance should be approximately between 110 and 200 ohms.

Results:

• OK - The measurement is within an acceptable range. Proceed to test step 4.

• NOT OK - The measurement is not within an acceptable range.

  Repair: The sensor signal circuits have failed. Wire L912-WH(White)or wire L913-OR(Orange)is open in the machine harness. Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK THE HARNESS FOR A SHORT TO THE RETURN.

1. The key start switch remains in the OFF position. The ECM remains disconnected from the machine harness.

2. Disconnect the machine harness from the sensor.

3. At the machine harness connectors J2 and J1, measure the resistance from contact J2-38 (wire L912-WH(White)) to contact J1-16 (wire L913-OR(Orange)).

Expected Result:

Each resistance should be greater than 5000 ohms.

Results:

• OK - The measurement is within an acceptable range. The machine harness is correct. Proceed to test step 5.

• NOT OK - The measurement is not within an acceptable range.

  Repair: There is a short in the machine harness. The short is between the + signal (wire L912-WH(White)) and the return (wire L913-OR(Orange)). Repair the machine harness or replace the machine harness.

  STOP

Test Step 5. CHECK THE HARNESS FOR A SHORT TO GROUND.

1. The key start switch remains in the OFF position. The sensor and the ECM remain disconnected from the machine harness.

2. At the machine harness connectors J2 and J1, measure the resistance from contact J2-38 (wire L912-WH(White)) to frame ground. Also, measure the resistance from contact J1-16 (wire L913-OR(Orange)) to frame ground.

Expected Result:

Each resistance should be greater than 5000 ohms.

Results:

• OK - The measurement is within an acceptable range. The machine harness is correct. Proceed to test step 6.

• NOT OK - The measurement is within an acceptable range.

  Repair: There is a short in the machine harness. The short is between the + signal and the frame ground or the short is between the + signal and wire 202-BK(Black). The short can also be between the return (wire L913-OR(Orange)) and the frame ground or the short can be between the return (wire L913-OR(Orange)) and wire 202-BK(Black). Repair the machine harness or replace the machine harness.

  STOP

Test Step 6. INSPECT THE SENSOR AND ADJUST THE SENSOR.

1. The key start switch remains in the OFF position. The sensor remains disconnected from the machine harness.

2. Remove the speed sensor. Inspect the sensor for damage or the presence of foreign material on the tip. Clean the tip if it is necessary. If the sensor is damaged, replace the sensor.

3. Install the speed sensor and adjust the speed sensor. Adjust the speed sensor properly when you are installing the sensor. See Testing and Adjusting, "Speed Sensor - Adjust".

Expected Result:

The speed sensor has been adjusted and inspected correctly. The diagnostic code is no longer active.

Results:

• YES - The speed sensor has been adjusted and inspected correctly. The diagnostic code is no longer active. Resume normal machine operation.

  STOP

• NO - The speed sensor has not been adjusted and inspected correctly. The diagnostic code is still active.

  Repair: Ensure that the speed sensor has been calibrated and inspected correctly.

  Proceed to test step 7.

Test Step 7. CHECK IF THE DIAGNOSTIC CODE REMAINS.

1. Inspect the contacts of the harness connectors and clean the contacts.

2. Reconnect all harness connectors.

3. Turn the key start switch to the ON position.

4. Enter the service mode of the Caterpillar Monitoring System and clear all inactive diagnostic codes.

5. Operate the machine.

6. Determine if CID 0190 FMI 08 is present. When the code is present, "SERV CODE" is shown.

Expected Result:

CID 0190 FMI 08 is NOT present. "SERV CODE" is NOT shown.

Results:

• OK - The diagnostic code is NOT present.

  Repair: The problem does not exist at this time. The new speed sensor corrected the problem. Resume normal machine operation.

  STOP

• NOT OK - The diagnostic code has not been corrected.

  Repair: It is unlikely that the ECM is faulty. Exit this procedure. Perform this procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP