Case IH 1914 – VCM: VCM - Rail 12VS2 - Backup Alarm Input Power Off

The control module has detected a loss of power, an open circuit, or a short on the specific 12-volt power rail (12VS2) responsible for supplying voltage to the machine's backup alarm circuit, causing the backup alarm to fail to sound when the machine is placed in reverse.

• skid steer
• Skid Steer Loaders
• Compact Track Loaders
• SR130
• SR150
• SR160
• SR175
• SR200
• SR210
• SR220
• SR240
• SR250
• SR270
• SV185
• SV250
• SV280
• SV300
• SV340
• 410
• 420
• 430
• 435
• 440
• 445
• 450
• 465
• 40XT
• 60XT
• 70XT
• TR270
• TR310
• TR320
• TR340
• TV380
• 420CT
• 440CT
• 445CT
• 450CT

1. 1

   Check the fuses and relays in the power distribution box assigned to the backup alarm and the VCM 12V supply rails for a blown fuse.

2. 2

   Inspect the physical condition of the backup alarm housing at the rear of the machine for damage from debris, pressure washing, or vibration.

3. 3

   Disconnect the pigtail connector at the backup alarm and use a multimeter to check for 12V when the machine is keyed on and drive controls are engaged in reverse.

4. 4

   If no voltage is present at the connector, trace the wiring harness back to the VCM to check for pinched wires, chafing against the chassis, or corroded pins at the VCM connector.

5. 5

   Bench test the alarm by applying 12V directly to its terminals. If it does not sound (107 DBA), the alarm unit has failed internally.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Alarm

   Open the rear heavy door/engine cover of the skid steer/track loader. The backup alarm is typically mounted to the rear chassis or inside the rear door panel.

3. 3

   Remove the Faulty Unit

   Disconnect the electrical connector from the backup alarm. Remove the mounting screws (often M4 x 0.7 x 16mm pan head screws) securing the alarm to the bracket.

4. 4

   Install the New Alarm

   Mount the replacement backup alarm using the existing hardware. Ensure the speaker face is pointed outward/downward to prevent water pooling inside the housing.

5. 5

   Reconnect and Seal

   Plug the electrical connector back in. Apply dielectric grease to the connector pins to protect against moisture and dust.

6. 6

   Test the System

   Reconnect the battery. Turn the key to the ON position, release the parking brake, and engage the controls in reverse. Verify the alarm sounds. The VCM should automatically clear the 1914 active code once the circuit continuity is restored.