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| Illustration 1 | g01539533 |
Schematic of the Boom Kickout Switch Circuit | |
The Boom Kickout Switch has two inputs to the ECM. The two inputs are normally open and normally closed. During normal operation, one of the inputs is open. The other input is grounded. When a circuit is measured with a voltmeter, an open circuit will measure approximately 13 DCV to ground and a closed circuit will measure approximately 0 DCV to ground.
An FMI 04 diagnostic code is recorded when both of the inputs are grounded.
The possible causes of this diagnostic code are listed below:
- The "normally open" signal circuit (wire J992-YL) is always shorted to ground.
- The "normally closed" signal circuit (wire J993-PK) is always shorted to ground.
- The switch has failed.
- The ECM has failed. This is unlikely.
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. Verify that all connections in the circuit are clean, secure and 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.
| Status of the Switch | |||
|---|---|---|---|
| MODE | Switch Position | J2-29 (N/O) J992-YL Circuit |
J2-30 (N/C) J993-PK Circuit |
| Released | Up | Open | Closed |
| Pressed | Down | Closed | Open |
System Response:
A level 2 warning is generated.
Test Step 1. CHECK THE SWITCH
- Turn the disconnect switch and the key start switch to the ON position. DO NOT START THE ENGINE.
- Ensure that the diagnostic code is active.
- Observe the status of the diagnostic code while disconnecting the switch connector from the machine harness.
Expected Result:
The CID 2961 FMI 04 diagnostic code will remain active if the switch is not the cause of the diagnostic code. The switch is the cause of the diagnostic code if the CID 2961 FMI 04 diagnostic code is NO longer active and a CID 2961 FMI 03 diagnostic code becomes active.
Results:
- OK - The CID 2961 FMI 04 diagnostic code remains active. The switch has not failed. Proceed to Test Step 2.
- NOT OK - The CID 2961 FMI 04 diagnostic code is NO longer active. A CID 2961 FMI 03 diagnostic code becomes active when the switch connector is disconnected. The machine harness and the ECM are operating correctly. The switch has failed.
Repair: Replace the Switch. After replacement of the switch, verify that the operation of the new switch is correct before operating the machine.
STOP
Test Step 2. CHECK THE HARNESS FOR A SHORT
The switch remains disconnected from the machine harness.
- Disconnect the machine harness connectors J1 and J2 from the Machine ECM.
- At the ECM machine harness connector J2, measure the resistance between contact J2-29 (wire J992-YL) to frame ground. Measure the resistance between contact J2-29 (wire J992-YL) to all of the other contacts that are used in the J1 and J2 connectors for the ECM.
- At the ECM machine harness connector J2, measure the resistance between contact J2-30 (wire J993-PK) to frame ground. Measure the resistance between contact J2-30 (wire J993-PK) to all of the other contacts that are used in the J1 and J2 connectors for the ECM.
Expected Result:
Each resistance measurement is greater than 5000 ohms.
Results:
- OK - Each resistance measurement is greater than 5000 ohms. The switch input circuits are not shorted in the machine harness. Proceed to Test Step 3.
- NOT OK - One or more of the resistance measurements is less than 5000 ohms.
Repair: A switch input circuit is shorted to the circuit with the low resistance measurement or is shorted to ground. Short circuits can be caused by dirty connections. Refer to the complete machine Electrical System Schematic. Check the connectors that are in the involved circuits. Verify that all connection points for the circuit are clean, secure and in good condition.For information on testing for short circuits and finding short circuits, refer to Troubleshooting, "Wiring Harness (Short Circuit) - Test". Repair the machine harness or replace machine harness.
STOP
Test Step 3. CHECK THE STATUS OF THE DIAGNOSTIC CODE
- Inspect the harness connectors and clean the contacts of the harness connectors. Check the wires for damage to the insulation that can be caused by excessive heat, battery acid, or chafing.
- Perform a 45 N (10 lb) pull test on each of the wires that are associated with the switch circuit.
- Reconnect all harness connectors. Make sure that the connectors are fully seated and the clips for each connector are completely fastened.
- Turn the disconnect switch and the key start switch to the ON position.
- Determine if the CID 2961 FMI 04 diagnostic code is active.
Expected Result:
The CID 2961 FMI 04 diagnostic code is not active.
Results:
- OK - The CID 2961 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 2961 FMI 04 diagnostic code is active. The diagnostic code has not been corrected.
Repair: Check the circuit again. Use the Caterpillar Electronic Technician (Cat ET) service tool, if available, in order to perform a "Wiggle Test" on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.If the cause of the problem is not found, the ECM may could be activating this diagnostic code in error. Prior to replacing an ECM, always contact your dealership's Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, replace the ECM that has activated the diagnostic code. Refer to Troubleshooting, "Electronic Control Module (ECM) - Replace".
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