Case IH 3693 – ECU: Glow Plug Circuit. - Short Circuit To Battery Error For Low Voltage System

This indicates that the engine's control system has detected a short circuit to battery voltage within the low-voltage glow plug heating circuit.

• Farmall
• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• rough terrain forklifts
• tractors

1. 1

   Monitor the fault to verify if the code is active or stored/intermittent, as no reaction is needed if the failure isn't present after a short time.

2. 2

   Inspect the glow plug circuit wiring harness between the Engine Control Unit, the Fast Glow Plug Control Unit (FGPCU), and the glow plugs for chafed wires or melted insulation causing a short to battery voltage.

3. 3

   Check the diagnostic output signal from the Fast Glow Plug Control Unit (FGPCU) to isolate whether the short is internal to the module or in the external wiring.

1. 1

   Disconnect battery

   Disconnect battery power before servicing the glow plug circuit to prevent further electrical damage.

2. 2

   Repair wiring harness

   Repair or replace any sections of the wiring harness that are confirmed to be shorting to battery voltage.

3. 3

   Follow OEM instruction

   If the wiring harness and glow plugs test fine, the official OEM service instruction dictates: "Replace Glow Plug Control Unit If Fault Persists".

4. 4

   Replace Glow Plug Control Unit

   Remove the faulty Glow Plug Control Unit and install the replacement module.

5. 5

   Reconnect battery

   Reconnect the battery.

6. 6

   Clear codes and verify

   Use the Case IH Electronic Service Tool (EST) to clear the fault codes and run the engine to verify the repair.