953C, 963C and 973C Track-Type Loaders Transmission Electronic Control System E623 Low Left Track Forward Steering Pressure Caterpillar

Conditions Which Generate This Code:

Illustration 1	g00419539
Schematic of the Solenoid Valve (left forward steering)

This event code is recorded when the ECM has determined that the pressure from the solenoid is too low.

The probable cause of this event code is the calibration is not correct.

The possible causes of this event code are listed below:

• The left forward steering has failed in the low-pressure position.

• The machine harness has failed.

• The ECM may have failed, but is unlikely.

System Response:

When this event code occurs, an alarm will sound. The event code will cause the transmission to shift to NEUTRAL. Limited operation at a reduced speed may be performed ONLY after you return the speed/direction control lever to the PARK position.

Note: Ensure that the E623 is on hold. The normal resistance of the coil at room temperature is 7.75 ohms. The following test procedure may create other diagnostic codes. Ignore these diagnostic codes and clear these diagnostic codes when the original event code is corrected.

Note: For additional troubleshooting of the hydraulic system, refer to Symptom 15 in Testing and Adjusting, RENR5226, "Troubleshooting".

Test Step 1. PERFORM THE TRACK SPEED CALIBRATIONS .

1. Turn OFF the engine.

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

3. Use the AVSpare Monitoring System to enter the calibration mode.

4. Enter Calibration Mode 5-13.

5. At the same time, hold down the "Clear" switch, and the "Sensor/Speed Calibrate" switch. Continue holding down both switches until the arrows that are shown on the main display module point in the up direction. That action resets the calibrations for submodes 1 through 9, 15, 16, and 17.

6. Perform the calibration for submodes 1 through 9, 15, 16, and 17. Refer to the Testing and Adjusting, "Right and Left Pedal Calibration (Submode 1, Submode 2 Submode 5 and Submode 6)", the Testing and Adjusting, "Center Pedal Calibration (Submode 3 and Submode 4)", the Testing and Adjusting, "Speed and Direction Lever Calibration (Submode 7, Submode 8 and Submode 9)", and the Testing and Adjusting, "Track Speed Calibration (Submode 15, Submode 16 and Submode 17)".

7. Operate the machine.

8. Check the status of the event code of E623.

Expected Result:

The event code of E623 is not active.

Results:

• YES - The event code of E623 is not active. The calibrations corrected the diagnostic code. resume normal operation.

  STOP

• NO - The event code of E623 is active. Go to Test Step 2.

Test Step 2. CHECK FOR DIAGNOSTIC CODES THAT ARE RELATED TO THE SOLENOID VALVE FOR THE LEFT FORWARD STEERING.

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

2. Check for diagnostic codes that are related to the solenoid.

   The related diagnostic codes are listed below:

   • CID 0469 FMI 03

   • CID 0469 FMI 05

   • CID 0469 FMI 06

Expected Result:

There are no other diagnostic codes that are related to the solenoid.

Results:

• YES - There are no other diagnostic codes that are related to the solenoid. Go to Test Step 3.

• NO - There are diagnostic codes that are related to the solenoid.

  Repair: Exit this procedure and perform the procedure for other related diagnostic codes.

  STOP

Test Step 3. CHECK THE CHARGE PRESSURE

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

2. Use a 3500 kPa (500 psi) gauge to verify that the charge pressure is set to 2850 ± 100 kPa (413 ± 14 psi).

   1. On the manifold, connect the 3500 kPa (500 psi) gauge to the "CHG" port.

   2. Turn ON the engine.

   3. Run the engine at high idle.

3. Measure the charge pressure.

Expected Result:

The charge pressure is 2850 ± 100 kPa (413 ± 14 psi).

Results:

• YES - The charge pressure is 2850 ± 100 kPa (413 ± 14 psi). Go to Test Step 4.

• NO - The charge pressure is not 2850 ± 100 kPa (413 ± 14 psi).

  Repair: Adjust the charge relief valve in order to set the charge pressure to 2850 ± 100 kPa (413 ± 14 psi).

  STOP

Test Step 4. CHECK THE PRESSURE SENSORS.

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

2. Disconnect the pressure gauge that was used in the previous Test Step.

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

4. Check for diagnostic codes that are related to the pressure sensors.

   The diagnostic codes that are associated with the pressure sensors are listed below:

   • CID 0136 FMI 03

   • CID 0136 FMI 04

   • CID 0137 FMI 03

   • CID 0137 FMI 04

   • CID 0132 FMI 08

Expected Result:

There are no diagnostic codes that are related to the pressure sensors.

Results:

• YES - There are no diagnostic codes that are related to the pressure sensors. Go to Test Step 5.

• NO - There are diagnostic codes that are related to the pressure sensors.

  Repair: Exit this procedure and perform the diagnostic procedure for the sensor with the active diagnostic code.

  STOP

Test Step 5. CHECK FOR HYDRAULIC CONTAMINATION AT THE SOLENOID.

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

2. Remove the solenoid from the hydraulic circuit.

3. Check the valve ports for contamination.

Expected Result:

There is no contamination.

Results:

• YES - There is no contamination. Go to Test Step 6.

• NO - There is contamination. The contamination caused the solenoid to fail.

  Repair: Replace the solenoid and service the hydraulic system.

  STOP

Test Step 6. CHECK IF THE EVENT CODE REMAINS

1. Connect the solenoid back to the machine.

2. Turn the disconnect switch to the ON position.

3. Start the machine.

4. Operate the machine.

5. Check if the E623 for the solenoid is active.

Expected Result:

The E623 for the solenoid is NOT active.

Results:

• YES - The E623 for the solenoid is NOT active. The event code does not exist at this time. Resume normal operation.

  STOP

• NO - The E623 for the solenoid is active. The ECM has failed.

  Repair: Is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the failure is not found, then replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP