DISC 9W1738 - Caterpillar

Illustration 1 g02653326
Auxiliary Third Function Port B Solenoid Valve connections
This diagnostic code is associated with the Auxiliary Third Function Port B Solenoid Valve (attachment). The FMI 06 means that the Implement ECM has determined that the current of the solenoid circuit is above normal. The ECM will apply a current amount that corresponds to the input signals from the operator controls.The possible causes of this diagnostic code are listed:
The energize circuit of the solenoid is shorted to ground.
The solenoid has failed.
The ECM has failed. This condition 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. 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. Note: The resistance of the solenoid coil should be 5 0.3 ohms at 25 °C (77.0 °F).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 0491 FMI 06 diagnostic code changes to a CID 0491 FMI 05 diagnostic code when the solenoid is disconnected.Results:
YES - The active CID 0491 FMI 06 diagnostic code changes to a CID 0491 FMI 05 diagnostic code when the solenoid is disconnected. The circuit is correct.Repair: The solenoid has failed. Repeat this test "CHECK THE SOLENOID" in order to verify the solenoid failure. Replace the solenoid.STOP
NO - The CID 0491 FMI 06 remains active when the solenoid is disconnected. 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 GROUND
Turn the key start switch and the disconnect switch to the OFF position.
The solenoid remains disconnected from the machine harness.
Disconnect the machine harness connectors J1 and J2 from the Implement ECM.
At the machine harness ECM connectors, measure the resistance between the contact J1-59 (wire E920-BR(Brown)) and frame ground. Measure the resistance between the contact J1-59 (wire E920-BR(Brown)) and each of the other J1 and J2 circuits that are used in the Implement ECM connectors. Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 3.
NOT OK - One or more of the resistance measurements is less than 5000 ohms. There is a short in the machine harness. The short is between wire E920-PU(Purple) and the circuit with the low resistance measurement. Repair: Repair the machine harness or replace the machine harness. STOPTest Step 3. CHECK