John Deere 003033.04 – CAB: Left Brake Pedal Position Sensor Voltage Low

The Cab Control Module has detected that the electrical signal voltage from the Left Brake Pedal Position Sensor is below the minimum expected normal operating range. This out-of-range low voltage indicates a potential open circuit, a short to ground, or a faulty sensor, which may negatively affect the proper operation of the braking system.

• 6M Series
• 7R Series
• 8R Series
• 8RT Series
• 9R Series
• 9RT Series
• 9RX Series

1. 1

   Perform a visual inspection of the left brake pedal position sensor, its mounting, and the pedal mechanism for any physical damage.

2. 2

   Examine the wiring harness and electrical connector at the sensor for loose connections, corrosion on the pins, or chafed, pinched, or broken wires.

3. 3

   Cycle the key switch to see if the code clears and reappears to determine if the fault is intermittent or persistent.

4. 4

   With the sensor connected and key in the 'Run' position, back-probe the signal wire with a multimeter. Voltage should be around 0.5V unpressed and increase smoothly when depressed. A zero or near-zero reading confirms the low voltage condition.

5. 5

   Disconnect the sensor and perform a continuity test between the sensor terminals. Continuity should change as the sensor's plunger is pressed and released to verify internal component function.

1. 1

   Prepare machine for service

   Park the machine on a level surface, engage the park brake, turn off the engine, and disconnect the battery before performing electrical work.

2. 2

   Access the sensor

   Remove trim panels or covers around the base of the steering column and pedals to gain access to the left brake pedal position sensor.

3. 3

   Perform Diagnostic Checks

   Follow the diagnostic checks listed above to confirm the source of the fault.

4. 4

   Repair wiring

   If diagnostic checks reveal a broken wire or corroded connector, repair or replace the damaged section of the harness and ensure all connections are clean and secure.

5. 5

   Replace the sensor

   If wiring is in good condition but the sensor failed testing, unplug the connector, remove mounting hardware, and install the new sensor. Ensure it is correctly aligned with the brake pedal mechanism.

6. 6

   Calibrate the sensor

   Use John Deere Service ADVISOR software or the machine's onboard diagnostic display to calibrate the new sensor. This teaches the control module the voltage range from the un-pressed to the fully-pressed position.

7. 7

   Clear codes and test

   Reconnect the battery, start the machine, and clear any stored fault codes. Operate the brake pedal to ensure the fault code does not return and the braking system functions correctly.