24M Motor Grader Implement Electronic Control System MID 082 - CID 2252 - FMI 04 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g03656454
"Machine Articulation Angle Position" Sensor location (View from the left side of the machine at the articulation hitch) (1) Articulation angle sensor (2) Mechanical linkage

Illustration 2	g03664497
Location of the position sensor for the angle of the machine articulation The view is from the left side of machine and the covers are removed. (3) Articulation angle sensor 1 (4) Articulation angle sensor 2 (2) Mechanical linkage

Illustration 3	g03656459
Connections for the single Machine Articulation Angle Position Sensor 2 with two outputs

Illustration 4	g03664499
Connections of machine articulation angle position sensor 2

Two articulation angle signals are required for correct operation of articulation on the machine. Either the two separate sensors or the dual output sensor will provide a PWM signal to the ECM.

This diagnostic code is recorded when the ECM reads the input signal from the machine articulation angle sensor signal 2 connected to each ECM at J2-17 and the voltage of the signal is below normal. The diagnostic code can be activated by any of the following:

• Implement ECM

• Transmission/Chassis ECM

• Both the Implement ECM and Transmission/Chassis ECM

The sensor is a PWM sensor that operates at a frequency of approximately 500 hertz. The PWM sensor sends a PWM input signal to the ECM. The variations in the duty cycle of the signal follows:

• When the machine is in the neutral position, the duty cycle will be 50%.

• When the machine is articulated to the full left position, the duty cycle will be approximately 69%.

• When the machine is articulated to the full right position, the duty cycle will be approximately 32%.

The following conditions could cause this diagnostic code to be activated:

• The signal circuit is shorted to ground.

• The sensor has failed.

• The ECM has failed. This is unlikely.

Note: Before performing this procedure, check for an active CID 0168 diagnostic code for the ECM supply voltage. Correct any problem with the 24 volt power supply before performing this procedure.

The Transmission/Chassis ECM (MID 027) and the Implement ECM (MID 082) receive an input signal from the articulation sensor signal 2. Both of the electronic control modules can activate a CID 2252 FMI 04 diagnostic code when a below normal voltage signal is detected.

If one ECM has activated a CID 2252 FMI 04 diagnostic code and the other ECM has not activated the diagnostic code, it is likely that the sensor is operating correctly. When this occurs, a poor connection in the machine harness would be suspected.

If both of the electronic control modules have activated the diagnostic code, it is unlikely that either ECM has failed.

For any of these conditions, proceed with this procedure in order to verify the cause of the problem.

Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Inspect the connections for the following:

• Connections are clean.

• Connections are secure.

• Connections are in good condition.

If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.

Note: The following test procedure may create other diagnostic codes. Clear the diagnostic codes when the original diagnostic code has been corrected.

Test Step 1. CHECK THE MECHANICAL LINKAGE

1. Turn the disconnect switch to the OFF position.

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

3. Remove any guards or shielding for the articulation sensors.

4. Check the mounting bolts of the articulation sensors. Ensure that the sensors are securely mounted.

5. Visually inspect the mechanical linkage of the articulation sensors. Verify the following:

   • All mechanical components are tight.

   • All mechanical components are in good condition.

   • The adjustment of the linkage is correct.

Expected Result:

All mechanical linkage and adjustment for the articulation sensor(s) are in good condition. No mechanical connections are loose.

Results:

• OK - All mechanical linkage and adjustment for the articulation sensor is correct. Proceed to Test Step 2.

• NOT OK - All mechanical linkage and adjustment for the articulation sensors is not correct.

  Repair: Perform the maintenance that is required in order to correct the problem with the mechanical connections for the articulation sensor(s). After the problem has been corrected, verify that this diagnostic code is still active before proceeding with this procedure.

  STOP

Test Step 2. CHECK THE SENSOR

1. Turn the disconnect switch to the ON position.

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

3. Ensure that the diagnostic code is active.

4. Observe the status of the diagnostic code while the sensor is disconnected from the machine harness.

Expected Result:

The CID 2252 FMI 04 diagnostic code is no longer active. A CID 2252 FMI 03 diagnostic code is now active.

Results:

• OK - The CID 2252 FMI 04 diagnostic code is no longer active. A CID 2252 FMI 03 diagnostic code is now active. The ECM and the circuit are correct. The position sensor is causing the problem.

  Repair: The sensor has failed. Replace the articulation angle 2 sensor. After replacement of the sensor, the sensor must be calibrated. Refer to the Testing and Adjusting, "Calibration" Story in this manual for the correct calibration procedure.

  STOP

• NOT OK - The CID 2252 FMI 04 diagnostic code remains active. Disconnecting the sensor did not affect the status of the active diagnostic code. The position sensor is not causing the problem. Proceed to Test Step 3.

Test Step 3. CHECK THE SIGNAL CIRCUIT FOR A SHORT TO GROUND

1. The sensor remains disconnected from the machine harness.

2. Turn the disconnect switch to the OFF position.

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

4. Disconnect the J1 and J2 machine harness connectors from the Implement ECM and the Transmission/Chassis ECM.

5. At machine harness connector J2 for the Implement ECM, perform the following:

   • Measure the resistance from contact J2-17 (wire U768-BU(Blue)) to frame ground.

   • Measure the resistance to all of the contacts that are used on the Implement ECM.

6. At machine harness connector J2 for the Transmission/Chassis ECM, perform the following:

   • Measure the resistance from contact J2-17 (wire U768-BU(Blue)) to frame ground.

   • Measure the resistance to all of the contacts that are used on the Implement ECM.

Expected Result:

Each resistance measurement is greater than 5000 ohms.

Results:

• OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 4.

• NOT OK - One or more of the resistance measurements is less than 5000 ohms. There is a short in the machine harness.

  Repair: There is a short in the machine harness between the signal circuit and the circuit with the low resistance.

  Refer to the Electrical Schematic of the machine. Check all of the connectors that are in the sensor circuit. Inspect the connections for the following:

  • Connections are clean.

  • Connections are secure.

  • Connections are in good condition.
  For information on testing for short circuits and finding short circuits, refer to the Testing and Adjusting, "Wiring Harness (Short Circuit) - Test" Story in this manual. Repair the machine harness or replace the machine harness.

  STOP

Test Step 4. CHECK THE OPERATION OF THE ECM

Note: This check should be performed on the ECM that has activated the diagnostic code. If both of the electronic control modules have activated the diagnostic code, perform this check on both of the electronic control modules.

1. The key start switch and the disconnect switch remain in the OFF position.

2. The machine harness connectors for the sensor and both the Implement ECM and the Transmission/Chassis ECM remain disconnected.

3. At the machine harness connector J2 for the ECM, use a 151-6320 Removal Tool to remove the sensor signal wire U768-BU(Blue) and the socket at contact J2-17 from the harness connector.

4. Reconnect the machine harness J2 connector to the ECM.

5. Turn the disconnect switch to the ON position.

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

7. Observe the status of the active CID 2252 FMI 04 diagnostic code.

Expected Result:

The CID 2252 FMI 04 diagnostic code is no longer active. A CID 2252 FMI 03 diagnostic code is now active.

Results:

• OK - The CID 2252 FMI 04 diagnostic code is no longer active. A CID 2252 FMI 03 diagnostic code was activated after the sensor signal wire was disconnected. The ECM has responded correctly to the open circuit condition in the sensor circuit. Reconnect the sensor signal wire in the ECM connector before proceeding to the next test step. Proceed to Test Step 5.

• NOT OK - The CID 2252 FMI 04 diagnostic code remains active. The status of the active diagnostic code does not change when the sensor signal wire is disconnected from the ECM.

  Repair: The ECM has not responded correctly to the open condition in the sensor circuit. The operation of the ECM is not correct.

  Prior to replacing an ECM, always contact your dealership's Technical Communicator for possible consultation with AVSpare. This consultation may greatly reduce repair time. If the ECM must be replaced, refer to the Testing and Adjusting, "Electronic Control Module (ECM) - Replace" Story in this manual.

  STOP

Test Step 5. CHECK THE STATUS OF THE DIAGNOSTIC CODE

1. Perform the following:

   • Visually inspect the harness connectors.

   • Clean the contacts of the harness connectors.

   • Visually inspect the insulation of the wires for damage that is caused by excessive heat, battery acid, or chafing.

2. Perform a 45 N (10 lb) pull test on each wire that is associated with the sensor circuit.

3. Reconnect all harness connectors. Verify the following:

   • Connectors are fully seated.

   • The clips for each connector are completely fastened.

4. Turn the disconnect switch to the ON position.

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

6. Operate the machine.

7. Determine if the CID 2252 FMI 04 diagnostic code is active.

Expected Result:

The CID 2252 FMI 04 diagnostic code is not active.

Results:

• OK - The CID 2252 FMI 04 diagnostic code is not active. The diagnostic code does not exist at this time. The initial diagnostic code was probably caused by a poor connection or a short at one of the connectors that was disconnected and reconnected. Resume normal operation.

  STOP

• NOT OK - The CID 2252 FMI 04 diagnostic code is active. The diagnostic code has not been corrected.

  Repair: Check the circuit again. Perform a Wiggle Test on the machine wiring harness with the AVSpare Electronic Technician (Cat ET) service tool. The Wiggle Test can detect the following in the machine wiring harness:

  • Momentary shorts

  • Intermittent shorts

  • Opens
  If the problem is still present, the ECM may have failed. This is unlikely due to the following:

  • The ECM responded correctly to the change of condition in the previous test step.
  Exit this procedure and perform this procedure again. If the cause of the failure is not found, replace the ECM that activated the diagnostic code.

  Prior to replacing an ECM, always contact your dealership's Technical Communicator for possible consultation with AVSpare. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, and the ECM must be replaced, refer to the Testing and Adjusting, "Electronic Control Module (ECM) - Replace" Story in this manual for additional information.

  STOP