PILLAR AS 4428571 - Caterpillar

Illustration 1 g03326688
Connections of the secondary brake solenoid
The CID 0722 diagnostic code is associated with the secondary brake solenoid. The circuit is connected to an ON/OFF output of the Power Train ECM. The FMI 06 means that the ECM has determined that the current of the solenoid circuit is above normal.The service brake switch is depressed when the service brake pedal is fully depressed. When the switch is depressed, system voltage is directed to the secondary brake solenoid through fuse 9 and the switch contacts. Then, the secondary brake is engaged. The resistance of the solenoid coil is approximately 42 ohms at 25° C (77° F). The resistance will increase as the temperatures increase.The possible causes of this diagnostic code are listed below:
The energize circuit of the solenoid is shorted to a ground source.
The solenoid has failed.
The ECM has failed. An ECM failure is unlikely.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the CID 0722 FMI 06 diagnostic code is active before performing this procedure.Note: 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, that all connections are secure, and that all connections are 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.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. CHECK THE SOLENOID
Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
Observe the status of the diagnostic code.
Disconnect the solenoid with the active diagnostic code from the machine harness.Expected Result:The active CID 0722 FMI 06 diagnostic code changes to a CID 0722 FMI 05 diagnostic code when the solenoid is disconnected.Results:
YES - The active CID 0722 FMI 06 diagnostic code changes to a CID 0722 FMI 05 diagnostic code when the solenoid is disconnected. The circuit is correct.Repair: The solenoid has failed. Repeat this Test Step to verify that the solenoid has failed and the circuit is correct. Replace the solenoid. Verify that the new solenoid corrects the problem.STOP
NO - The CID 0722 FMI 06 diagnostic code remains active when the solenoid is disconnected. Disconnecting the solenoid did not change the status of the diagnostic code. The solenoid is not causing the problem. Proceed to Test Step 2.Test Step 2. CHECK THE ENERGIZE CIRCUIT OF THE SOLENOID FOR A SHORT TO GROUNDThe solenoid remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connectors from the ECM.
At the machine harness connectors for the ECM, measure the resistance from the contact J2-5 wire (G731-GY(Grey)) to a clean source of frame ground. Measure the resistance from contact J2-5 wire (G731-GY(Grey))