John Deere 920.03 – BLC, SDM, or CLC: Audible Alarm Short to High

The control module is detecting a voltage on the audible alarm (warning horn/buzzer) circuit that is higher than expected, indicating a short to power in the wiring harness or an internal short within the alarm itself.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC
• 9470RT
• 9520RT
• 9570RT
• 310J
• 310SJ
• 410J
• 315SJ
• 944K Hybrid
• 859M Tracked Feller Buncher
• 7400A TerrainCut Mowers

1. 1

   Perform a harness tug test near the alarm and control module while monitoring active codes or listening for erratic beeping to check for harness or connector defects.

2. 2

   Disconnect the alarm (H2) and the control module connector to perform a voltage/continuity check on the signal wires, looking for a short to power (battery voltage present when dead) or an open circuit.

3. 3

   Measure the resistance across the terminals of the audible alarm itself (e.g., approximately 1.5k ohms on SDM systems) to check for an internal short or out-of-spec reading.

1. 1

   Locate the Alarm

   Access the audible alarm/warning horn. Depending on the machine, this is usually located inside the cab console, behind the display monitor, or under the dash.

2. 2

   Inspect Connectors

   Disconnect the alarm and inspect the connector pins for corrosion, moisture intrusion, or pushed-out pins. Do the same at the BLC/SDM/CLC module.

3. 3

   Isolate the Fault

   If the wiring harness tested fine during the diagnostic phase (no shorts to power found in the wires), the fault is isolated to the alarm itself.

4. 4

   Replace or Repair

   If the harness is shorted to a power wire, locate the chafe point (often where the harness routes around metal cab brackets) and repair the wire. If the alarm failed the resistance test, replace the audible alarm unit.

5. 5

   Verify

   Reconnect all components, turn the key to the ON position, and verify that the 000920.03 code changes from 'Active' to 'Stored'. Clear the stored diagnostic trouble codes (DTCs) via the monitor menu.