John Deere 974.03 – ACU, EPC, ECM / ECU, UIC: Hand Throttle Potentiometer Voltage Too High

Voltage Too High condition in the Hand Throttle Potentiometer circuit. The control unit has measured a voltage in excess of 4.7 volts at the signal input of the hand throttle potentiometer (sensor B96, lead 6018), pointing to a short to a positive lead, an open circuit, or a problem with the ground connection.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 7720
• 7820
• 7920
• 7810
• 9330
• 9430
• 9530
• 9630
• 9470RT
• 9520RT
• 9570RT
• 6165J
• 6185J
• 6205J
• 6210J
• 3029 Diesel Engine

1. 1

   Inspect Wiring and Connections: Check the wiring harness and connectors leading to the hand throttle potentiometer (B96) for any signs of physical damage, loose connections, or corrosion.

2. 2

   Check for Short Circuits: Inspect the circuit for any signs of shorting to a positive lead or an open circuit.

3. 3

   Verify Ground Connection: Ensure that the ground connection in the potentiometer's circuit is secure and free of corrosion.

4. 4

   Test Potentiometer: Use a multimeter or diagnostic tool to test the hand throttle potentiometer for proper functionality and voltage output.

1. 1

   Place the tractor in park and shut off the engine.

   Place the tractor in park and shut off the engine.

2. 2

   Locate the hand throttle potentiometer

   Locate the hand throttle potentiometer (sensor B96) on the operator controls/armrest.

3. 3

   Disconnect the sensor and inspect the pins

   Disconnect the sensor and inspect the pins for corrosion, moisture, or damage.

4. 4

   Measure the voltage at the harness connector

   Measure the voltage at the harness connector to verify if the short is in the wiring harness or internal to the sensor itself.

5. 5

   Repair or replace any damaged wiring or connectors.

   Repair or replace any damaged wiring or connectors.

6. 6

   Replace the hand throttle potentiometer

   If the wiring is intact and the sensor is outputting out-of-range voltage (above 4.7V), replace the hand throttle potentiometer.

7. 7

   Reconnect the sensor, restart the tractor, and test

   Reconnect the sensor, restart the tractor, and test the hand throttle to ensure the error code does not reoccur. (Note: Some codes may require manual clearing via the CommandCenter or diagnostic tool).