TUBE AS 3774483 - Caterpillar

Illustration 1 g00506532
Schematic of Action AlarmThe diagnostic code is recorded when the VIMS module reads the current of the action alarm circuit (410-WH) and the current is below normal. The action alarm may not SOUND or may be weak when this diagnostic code is active.
CHECK THE ALARM.
Disconnect the alarm from the machine harness.
At the machine harness connector for the alarm, place a jumper wire across the two contacts.Expected Result: The diagnostic code CID 0271 FMI 05 is no longer active.Results:
OK - The diagnostic code CID 0271 FMI 05 is no longer active. The alarm is open. Replace the action alarm. Verify that the action alarm is open. The correct resistance for a good alarm is 200 100 ohms. STOP.
NOT OK - The diagnostic code CID 0271 FMI 05 is still active. The action alarm is not causing the fault. Proceed to 2.
CHECK THE HARNESS.
Turn the disconnect switch and the key start switch to the OFF position.
The jumper wire placed in the 1 CHECK THE ALARM test remains connected to the machine harness.
Disconnect the machine harness from the main module.
At the machine harness connector for the module, measure the resistance between contact 24 (wire 410-WH) and frame ground.Expected Result: The resistance is less than 5 ohms.Results:
OK - Resistance is less than 5 ohms. The harness circuit resistance is correct. Proceed to 4.
NOT OK - Resistance is greater than 5 ohms. The harness circuit is open. Proceed to 3.
CHECK THE HARNESS.
Turn the disconnect switch and the key start switch to the OFF position.
The machine harness remains disconnected from the action alarm.
Remove the jumper wire that was placed in 1 CHECK THE ALARM.
Check for an open in the action alarm circuit (wire 410-WH). Measure the resistance between the main module harness connector (contact 24) and the action alarm machine harness connector (contact 1).
Check for an open in the action alarm (return or ground) circuit (wire 201-BK or 251-BK). Measure the resistance between the action alarm machine harness connector (contact 2) and the frame ground.Expected Result: The resistance measurements are less than 5 ohms.Results:
OK - Resistance is less than 5 ohms. The machine harness is correct. The fault is intermittent. Proceed to 4.
NOT OK - Resistance is greater than 5 ohms. The machine harness is not correct. Repair the machine harness or replace the machine harness. STOP.
CHECK THE MODULE.
Reconnect the machine harness connector to the main module.
Reconnect the alarm to the machine harness.
Turn the disconnect switch and the key start switch to the ON position.Expected Result: The diagnostic code has not changed. The diagnostic code CID 0271 FMI 05 is still active.Results:
YES - Diagnostic code has not changed. Diagnostic code CID 0271 FMI 05 remains active. The main module has failed. Replace the main module. See Testing and Adjusting, "Module - Replace". STOP.
NO - Diagnostic code is NO longer active. The main module is not causing the diagnostic code. The diagnostic code is intermittent. The probable cause is a poor electrical connection at the harness connectors or a damaged harness. Check the