D3K2, D4K2 and D5K2 Track-Type Tractors Systems Switch Circuits - Test Caterpillar


Switch Circuits - Test
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D3K2, D4K2 and D5K2 Track-Type Tractors Systems [UENR5465]
ELECTRICAL AND STARTING SYSTEM
SWITCH GP
D3K2, D4K2 and D5K2 Track-Type Tractors Systems Relay - Test
D3K2, D4K2 and D5K2 Track-Type Tractors Systems Switch Circuits - Test

Table 1
    Machine ECM (MID 39)    
MID     DTC     Description    
39     70-3     Parking Brake Switch: Voltage Above Normal    
39     70-4     Parking Brake Switch: Voltage Below Normal    
39     91-2     Throttle Position Switch: Data Erratic, Intermittent, Or Incorrect    
39     298-3     Service Brake Pedal Switch: Voltage Above Normal    
39     298-4     Service Brake Pedal Switch: Voltage Below Normal    
39     490-3     Implement Lockout Switch: Voltage Above Normal    
39     490-4     Implement Lockout Switch: Voltage Below Normal    
39     2438-3     Winch Free Spool Switch: Voltage Above Normal    
39     2438-4     Winch Free Spool Switch: Voltage Below Normal    
39     2481-3     Winch Drive Away Switch: Voltage Above Normal    
39     2481-4     Winch Drive Away Switch: Voltage Below Normal    
39     2679-3     Blade Shake Switch: Voltage Above Normal    
39     2679-4     Blade Shake Switch: Voltage Below Normal    
39     2754-2     Auxiliary #1 Valve Switch: Data Erratic, Intermittent, Or Incorrect    
39     2755-3     Blade Control Mode Switch: Voltage Above Normal    
39     2755-4     Blade Control Mode Switch: Voltage Below Normal    
39     3020-3     Auxiliary Valve #1 Float Switch: Voltage Above Normal    
39     3020-4     Auxiliary Valve #1 Float Switch: Voltage Below Normal    
39     3209-3     Auxiliary Valve #2 Float Switch: Voltage Above Normal    
39     3209-4     Auxiliary Valve #2 Float Switch: Voltage Below Normal    
39     3587-3     Stable Blade Switch: Voltage Above Normal    
39     3587-4     Stable Blade Switch: Voltage Below Normal    
39     3796-3     Traction Control Switch: Voltage Above Normal    
39     3796-4     Traction Control Switch: Voltage Below Normal    
39     4328-3     Bi-Directional Auto Shift Selector Dial voltage above normal    
39     4328-4     Bi-Directional Auto Shift Selector Dial voltage below normal    

Prior to beginning this procedure, inspect the harness connectors that are involved in this 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. Check the wiring for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing a troubleshooting procedure.

Possible Causes for an FMI 2 Diagnostic code are:

  • A short circuit exists.

  • An open circuit exists.

  • The switch has failed.

  • The ECM has failed. A failure of the Machine ECM is unlikely.

Possible Causes for an FMI 3 Diagnostic code are:

  • The ground wire is open.

  • A signal is permanently open.

  • The switch has failed.

  • The ECM has failed. A failure of the Machine ECM is unlikely.

Possible Causes for an FMI 4 Diagnostic code are:

  • A short to ground.

  • The switch has failed.

  • The ECM has failed. An ECM failure is unlikely.




Illustration 1g03722681

Switch connections for the Machine ECM.




Illustration 2g03722687

Switch connections for the Implement (Winch / Ripper) ECM.

Note: The diagrams above are a simplified schematic of the ECM switch connections. The schematics are electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic for the complete schematic.

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

Table 2
Troubleshooting Test Steps     Values     Results    
1. Identify Active FMI Code Associated With The Switch Circuit    
Code present.    
FMI 2 diagnostic code, proceed to Test Step 2.

FMI 3 diagnostic code, proceed to Test Step 5.

FMI 4 diagnostic code, proceed to Test Step 8.    
2. Check The Switch

A. Turn the disconnect switch and the key start switch OFF.

B. Disconnect the switch from the machine harness.

C. Measure the resistance between the return or ground pin and all input pins, one at a time.

D. Move the switch through the range of selections, and verify continuity.    

The resistance should be less than 5 Ω when switch operation indicates continuity, and greater than 5K Ω when switch operation indicates no continuity.    
OK - The resistance is as expected.

Proceed to Test Step 3.

NOT OK - The resistance is not as expected.

Repair: Replace the switch. Verify that the new switch resolves the diagnostic code.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the switch. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

STOP    
3. Check The Circuit For An Open

A. Turn the disconnect switch and the key start switch OFF.

B. Disconnect the switch and ECM from the machine harness.

C. Use a jumper wire between each contact on the machine harness at the switch end, one at a time.

D. Measure the resistance at the corresponding ECM harness pins.    

The resistance is less than 5 Ω.    
OK - The resistance is less than 5 Ω.

Proceed to Test Step 4.

NOT OK - The resistance is greater than 5K Ω.

Repair: The circuit wire is open in the machine harness. Repair or replace the machine harness.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

STOP    
4. Check The Circuit For A Short

A. The harness connectors for the switch and ECM remain disconnected.

B. Remove any jumper wires used from a previous test step.

C. At the machine harness connector for the ECM measure the resistance between the signal circuits and every other contact in the wiring harness.    

The resistance is greater than 5K Ω.    
OK - The resistance is correct.

Proceed to Test Step 10.

NOT OK - The resistance check is not correct.

Repair: There is a short in the signal circuits of the machine harness. Repair or replace the machine harness.

STOP    
Begin Process For FMI 3 Troubleshooting HERE    
5. Check the Ground Circuit Of The Switch In The Harness

A. Turn key start switch and disconnect switch OFF.

B. Disconnect the switch from the machine harness.

C. Measure the resistance between the return contact on the harness to ground.    

The resistance is less than 5 Ω.    
OK - The circuit is correct.

Proceed to Test Step 6.

NOT OK - The resistance is greater than 5K Ω. The circuit is open.

Repair: Repair or replace the machine harness.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

STOP    
6. Check The Switch

A. Measure the resistance from the normally open contact to the switch return or ground. Toggle the operation of the switch and observe resistance changes.

B. Measure the resistance from the normally closed contact to the switch return or ground. Toggle the operation of the switch and observe resistance changes.    

Open resistance should be greater than 5K Ω. Closed resistance should be less than 5 Ω. The normally open circuit should have open resistance and the normally closed circuit should have closed resistance. These values should reverse when the switch is engaged.    
OK - The measurements are correct.

Proceed to Test Step 7.

NOT OK - One or more of the measurements was incorrect.

Repair: Replace the switch. Verity that the new switch corrects the diagnostic code.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

STOP    
7. Check The Signal Circuits For An Open

A. Reconnect the switch to the machine harness.

B. Repeat Test Step 5, however instead of measuring the resistance from the switch contacts, measure from the corresponding contacts on the ECM harness.    

Open resistance should be greater than 5KΩ. Closed resistance should be less than 5 Ω. The normally open circuit should have open resistance and the normally closed circuit should have closed resistance. These values should reverse when the switch is engaged.    
OK - The measurements are correct.

Proceed to Test Step 10.

NOT OK - One or more of the measurements was incorrect.

Repair: Repair or replace the machine harness.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

STOP    
Begin Process For FMI 4 Troubleshooting HERE    
8. Check The Switch

A. Measure the resistance from the normally open contact to the switch return or ground. Toggle the operation of the switch and observe resistance changes.

B. Measure the resistance from the normally closed contact to the switch return or ground. Toggle the operation of the switch and observe resistance changes.    

Open resistance should be greater than 5K Ω. Closed resistance should be less than 5 Ω. The normally open circuit should have open resistance and the normally closed circuit should have closed resistance. These values should reverse when the switch is engaged.    
OK - The measurements are correct.

Proceed to Test Step 9.

NOT OK - One or more of the measurements was incorrect.

Repair: Replace the switch. Verity that the new switch corrects the diagnostic code.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

STOP    
9. Check The Signal Circuits For An Open

A. Reconnect the switch to the machine harness.

B.Repeat Test Step 5, however instead of measuring the resistance from the switch contacts, measure from the corresponding contacts on the ECM harness.    

Open resistance should be greater than 5K Ω. Closed resistance should be less than 5 Ω. The normally open circuit should have open resistance and the normally closed circuit should have closed resistance. These values should reverse when the switch is engaged.    
OK - The measurements are correct.

Proceed to Test Step 10.

NOT OK - One or more of the measurements was incorrect.

Repair: Repair or replace the machine harness.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

STOP    
10. Check If The Diagnostic Code Remains

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

B. Perform a
45 N (10 lb.) pull test on each of the wires that are associated with the circuit.

B. Reconnect all harness connectors.

C. Turn key start switch and disconnect switch ON.

D. Operate the machine.

Check the status of the diagnostic code.    

The diagnostic code is not active.    
OK - The diagnostic code is still active.

Repair: Check the status of the diagnostic code. If the cause of the problem is not found, the ECM may require replacement.

Prior to replacing the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may greatly reduce repair time.

If the ECM requires replacement, see Troubleshooting, "ECM - Replace"

STOP

NOT OK - The continuity check is not correct.

Repair: There is an open in the signal circuits of the machine harness. Repair or replace the machine harness.

STOP    

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