John Deere 3510.03 – Engine Control Unit (ECU): Sensor Supply #2 Voltage Out of Range High

The control module detects that the voltage on the 5-volt sensor supply circuit #2 is exceeding the specified limit (typically above 5.2 volts for more than 2 seconds). This almost always indicates that the 5-volt circuit has shorted to a higher voltage source, such as a 12-volt battery circuit. To protect the sensors from high-voltage damage, the module may deactivate the affected sensors, which can lead to erroneous measurements, reduced functionality, or an engine derate.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 5065M
• 5075M
• 5095M
• 5095MH
• 5105M
• 5015ML
• 8000 series
• 9000 series
• 8130
• 8430
• 9230
• 9470RT
• 9520RT
• 9570RT
• 4930
• 770G
• S-Series
• T-Series
• W-Series

1. 1

   Inspect the ECU's 5-volt supply circuit #2 and all connected sensors for chafed wires, melted insulation, or pinched harnesses that could be shorting to a 12-volt power source.

2. 2

   If diagnosing 8000/9000 Series Tractors (or similar models): Perform the 'Lift Pump Interference' test. Unplug the 6-way connector on the fuel lift pump and rerun the interactive harness diagnostic test to see if the code clears, indicating pump interference.

3. 3

   Check the transfer pump duty cycle via Service Advisor (typical values are 15-20% without load, 30-50% with load; higher values indicate a failing pump).

1. 1

   Isolate the Short

   Disconnect sensors on the #2 5-volt supply circuit one by one while monitoring the live voltage via Service Advisor or a multimeter. If the voltage drops back to 5V when a specific sensor is unplugged, that sensor is internally shorted and must be replaced.

2. 2

   Repair the Harness

   If unplugging sensors does not resolve the high voltage, trace the wiring harness back to the ECU. Repair or splice any sections where the 5V wire is exposed and touching a 12V wire.

3. 3

   Replace the Lift Pump

   If diagnosing an 8000/9000 series tractor and the lift pump failed the unplug test (Solution 77089), replace the electric fuel lift pump.

4. 4

   Clear and Verify

   Clear the ECU fault codes. Cycle the key and run the engine to verify that the 5-volt supply remains within the normal 4.8V–5.2V range and the code does not return.