John Deere 003509.06 – AIC / SFA: 5V Sensor Supply Current Too High

The control unit has detected an excessive current draw (current too high) on a 5-volt sensor supply circuit, typically caused by a short circuit to ground in a sensor or the wiring harness. To prevent damage, the control unit shuts down the 5V supply, which disables all sensors on that circuit and often triggers additional fault codes.

• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC
• 6MC
• 6RC
• 6M Series
• 6R Series
• 9470RT
• 9520RT
• 9570RT

1. 1

   Check for other active fault codes; multiple sensor-related codes indicate they share the faulty 5V supply circuit.

2. 2

   Visually inspect wiring harnesses connected to the implicated control unit (AIC or SFA) and its sensors for chafed wires, pinched areas, melted insulation, or corrosion.

3. 3

   Verify battery voltage is stable and within specification, as low voltage can cause erroneous codes.

4. 4

   Check all main ground connections for the cab, frame, and control units to ensure they are clean, tight, and free of corrosion.

1. 1

   Identify affected circuit

   Consult the technical manual for the specific tractor model to identify which control unit (AIC or SFA) is logging the code and which sensors are on its 5V supply circuit #1.

2. 2

   Isolate the circuit

   Turn the key switch to the OFF position and disconnect all sensors powered by the affected 5V supply circuit (e.g., hitch, throttle, armrest controls).

3. 3

   Check for persistent short

   Turn the key switch to the ON position (engine off) and check if fault code 003509.06 is still active. If the code is gone, the short is in a sensor. If it remains, the short is in the wiring harness.

4. 4

   Identify faulty sensor (if applicable)

   If the fault cleared in step 3, reconnect the sensors one by one, cycling the key each time. The sensor that causes the fault code to reappear is the shorted component and must be replaced.

5. 5

   Identify harness short (if applicable)

   If the fault persisted in step 3, turn the key OFF and disconnect the main connector at the control unit. Use a multimeter to measure resistance (Ohms) between the 5V supply pin and chassis ground. Low resistance confirms a short to ground. Trace the wire to find and repair the damage.