320E and 323E Excavators Machine Electronic Control System MID 299, 5322-6 Caterpillar

Conditions Which Generate This Code:

Illustration 1	g06010793
Schematic of the "Solenoid Return 6" circuit associated with the "Stick Cylinder Extend" solenoid.

The "Solenoid Return 6" diagnostic code is associated with the "Stick Cylinder Extend" solenoid. The FMI 06 diagnostic code means that the Machine ECM has detected the current is above normal.

The possible causes of this failure are listed here:

• The solenoid energizer circuit is shorted to ground.

• The solenoid has failed.

• The Machine ECM has failed. This condition is unlikely.

When this failure occurs, a warning is displayed on the operator monitor and the Machine ECM disables the circuit.

Note: The following test procedure may create other diagnostic codes. Ignore these created failures and clear the failures when the original diagnostic code is corrected.

Test Step 1. CHECK THE SOLENOID.

1. Turn the disconnect switch and the key start switch to the ON position. DO NOT start the engine.

2. Ensure that the diagnostic code is active on the operator monitor or via Cat^® ET.

3. Disconnect the suspect solenoid from the machine harness.

4. Observe the active diagnostic code on the operator monitor or via Cat^® ET.

Expected Result:

The diagnostic code has been replaced by a new diagnostic code displayed on the operator monitor.

Results:

• YES - The diagnostic code has been replaced by a new diagnostic code displayed on the operator monitor. The Machine ECM is operating correctly.

  Repair: The solenoid has failed. Replace the solenoid.

  STOP

• NO - The failure message remains active. Proceed to test step 2.

Test Step 2. CHECK THE SOLENOID ENERGIZER CIRCUIT FOR A SHORT TO GROUND.

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

2. The solenoid remains disconnected from the machine harness.

3. Disconnect the machine harness connectors from the Cat^® Grade Control ECM.

4. At the number 3 connector of the machine harness, measure the resistance between contact 1 (wire K764-WH(White)) and all the possible sources of ground.

Expected Result:

There should be greater than 5000 ohms resistance (no continuity).

Results:

• OK - The resistance measurements were greater than 5000 ohms. The harness is correct. Proceed to test step 3.

• NOT OK - The resistance is less than 5000 ohms. The harness is incorrect. The short is between the signal circuit (wire K764-WH(White)) and the circuit with the lowest resistance measurement.

  Repair: Repair the machine harness or replace the machine harness.

  STOP

Test Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.

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

2. Reconnect all harness connectors.

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

4. Clear all active events on the operator monitor or in Cat^® ET.

5. Operate the machine.

6. Observe the operator monitor. The diagnostic information may also be viewed in Cat^® ET.

Expected Result:

The diagnostic code is not active on the operator monitor.

Results:

• YES - The diagnostic code is not active. The failure does not exist currently. The initial failure was probably caused by a poor electrical connection or a short at one of the harness connections that was disconnected and reconnected. Resume normal machine operation.

  STOP

• NO - The diagnostic code is active on the message center. The failure has not been corrected. The ECM may have failed. A failure of the ECM is unlikely. Exit this procedure and perform this procedure again.

  Repair: If the cause of the failure is not found, replace the ECM. See Testing And Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP