950M and 962M Wheel Loaders Caterpillar

Solenoid Valve (Switch Controlled) - Test

Usage:

962M EJB

Implement ECM

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the solenoid valve (switch controlled) circuits of the machine.

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Table 1
Implement ECM MID 82
DTC	Description	System Response
1530-3	Quick Coupler Solenoid: Voltage Above Normal	The system will be inoperable. Operator will be unable to remove or attach implements requiring use of quick coupler function. This code is triggered when there is a short to battery.
1530-5	Quick Coupler Solenoid: Current Below Normal	The system will be inoperable. Operator will be unable to remove or attach implements requiring use of quick coupler function. This code is triggered when there is an open circuit.
1530-6	Quick Coupler Solenoid: Current Above Normal	The system will be inoperable. Operator will be unable to remove or attach implements requiring use of quick coupler function. This code is triggered when there is a short to ground.

Possible causes for an FMI 3 Diagnostic code are:

The power circuit of the solenoid is shorted to a higher voltage source.
The solenoid has failed.
The ECM has failed. This situation is unlikely.

Possible causes for an FMI 5 Diagnostic code are:

The energize circuit of the solenoid is open.
The return circuit of the solenoid is open.
The solenoid has failed.
The ECM has failed. This situation is unlikely.

Possible causes for an FMI 6 Diagnostic code are:

A short to ground exists.
The solenoid has failed.
The ECM has failed. This situation is unlikely.

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Illustration 1	g03644416
Schematic of the Switch Controlled Solenoid circuits

Note: The diagram above is a simplified schematic of the connections for the switch controlled solenoid circuits. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR3117 for the complete schematic.

Diagnostic Trouble Code Procedure

Note: 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. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Identify Active FMI Code Associated With Solenoid Circuit	Code present.	FMI 3 diagnostic code, proceed to Test Step 2. FMI 5 diagnostic code, proceed to Test Step 3. FMI 6 diagnostic code, proceed to Test Step 5.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Machine Harness For A Short A. Turn the key start switch and the disconnect switch OFF. B. Disconnect the harness connection at solenoid. C. If the solenoid is connected to ECM, disconnect J1 and J2 connectors from ECM. If the solenoid is connected to the switch panel, disconnect all switch panel connectors. D. Measure the resistance of solenoid signal contact to all J1 and J2 connectors.	Each reading is greater than 5K Ω.	OK - All resistance readings are greater than 5K Ω . Proceed to Test Step 7. NOT OK - One or more readings are less than 5 Ω. Repair - A short exists between the signal contact and the circuit with the low resistance. 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 5 Troubleshooting HERE
3. Check The Solenoid. A. Turn the key start switch and the disconnect switch OFF. B. Disconnect the solenoid from the machine harness. C. Place a jumper wire between contact 1 and contact 2, at the harness connector for the solenoid. D. Turn the key start switch and the disconnect switch ON. Do not start the engine. E. As the jumper is removed and connected to the contacts, observe any code change.	The code changes to FMI 6 after the jumper wire is installed.	OK - The circuit is correct, the solenoid has failed. Repair: Replace the solenoid. After replacement of the solenoid, confirm the diagnostic code is not active. STOP NOT OK - The diagnostic code remains active. Proceed to Test Step 4.
4. Check The Machine Harness For An Open. A. Turn the key start switch and the disconnect switch OFF. B. Disconnect the harness connectors from the ECM (or switch panel). C. The jumper wire remains installed. D. At the machine harness connector for the ECM, measure the resistance at the ECM contacts for the solenoid.	Each reading is less than 5 Ω.	OK - The reading is less than 5 Ω, the harness is correct. Proceed to Test Step 7. NOT OK - The reading is greater than 5K Ω. Circuit open in machine harness. Repair : The open is in the wire for the solenoid signal or the return wire for the solenoid. 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 6 Troubleshooting HERE
5. Check The Solenoid A. Turn the key start switch and the disconnect switch OFF. B. Disconnect the solenoid from the machine harness. C. Place a jumper wire between contact 1 and contact 2, at the harness connector. D. Turn the key start switch and the disconnect switch ON. Do not start the engine. E. As the jumper is removed and connected to the contacts, observe any code change.	The FMI 6 diagnostic code changes to an FMI 5 diagnostic code after the jumper wire is installed.	OK - The circuit is correct. The solenoid has failed. Repair: Repeat the jumper wire test. Verify the solenoid failure. Replace the solenoid. Note: After the solenoid is replaced, confirm that the diagnostic code is no longer active. STOP NOT OK - The diagnostic code remains active. Proceed to Test Step 6.
6. Check Machine Harness For A Short To Ground A. The machine harness remains disconnected from the solenoid. B. Turn the key start switch and the disconnect switch OFF. C. Disconnect the harness connectors from the ECM. D. At the harness connector for ECM, measure the resistance between the solenoid signal contact and all ground contacts.	Each reading is greater than 5K Ω.	OK - Machine harness correct. Proceed to Test Step 7. NOT OK - One or more of the resistance measurements are less than 5 Ω. A short circuit exists in the machine harness. Repair: A short circuit exists between the wire for the signal wire of the solenoid and the circuit with the low resistance. 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
7. Check If The Diagnostic Code Remains A. Turn the key start switch and the disconnect switch ON. B. Clear all diagnostic codes. C. Operate the machine. D. Stop the machine and engage the safety lock lever. E. Check if diagnostic code for the solenoid is active.	Code for solenoid is NO longer present.	OK - The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP NOT OK - The diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing the ECM, always contact the Technical Communication at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced. STOP