Massey Ferguson 05.03.54 – Transmission Control Module (TCU) / TRANS1: Issue With Left Brake Pedal Switch Signal

The transmission controller is receiving an illogical, out-of-range, or missing electrical signal from the left-hand brake pedal sensor (X66), which can prevent the transmission from operating correctly.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 6614
• 6615
• 6616
• 6700 S Series
• 7700 S Series
• 8700 S Series

1. 1

   Inspect the left brake pedal linkage and the physical mounting of the X66 sensor to ensure alignment and that the pedal returns fully to its resting position.

2. 2

   Examine the wiring harness leading to the left brake pedal sensor for rub points, pinched wires, or corrosion inside the connector.

3. 3

   Using a multimeter, check the sensor's power supply, ground integrity, and signal wire for an open circuit, a short to ground (0V), or a short to power (+12V).

4. 4

   Monitor live data for the left brake pedal position using a diagnostic tool; the signal should change smoothly as the pedal is depressed.

1. 1

   Preparation

   Park the tractor on a level surface, engage the parking brake, turn off the ignition, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the Sensor

   Access the pedal box area inside the cab. Locate the left-hand brake pedal sensor (X66), which is mounted on the linkage assembly of the left brake pedal.

3. 3

   Removal

   Carefully unplug the electrical connector from the sensor. Remove the mounting screws/bolts securing the sensor to the bracket, and slide the faulty sensor off the pedal linkage.

4. 4

   Installation

   Position the new sensor onto the linkage in the exact orientation as the old one. Secure it with the mounting hardware, ensuring it is properly aligned so the pedal movement sweeps the sensor's full range, and reconnect the electrical harness.

5. 5

   Calibration & Testing

   Reconnect the battery. Turn the ignition on and use a diagnostic tool to clear the 05.03.54 fault code. Test the brake pedals to ensure the transmission responds correctly. Depending on the Autotronic version, a pedal calibration routine via the tractor's terminal may be required.