John Deere 598.03 – PTA / TCU: Clutch Pedal Switch, Voltage Too High

The Transmission Control Unit (TCU) has detected an abnormally high voltage signal from the S72 clutch pedal switch circuit. This indicates that the voltage in the component's circuit is above the normal range, which is typically caused by a short circuit to a power source in the wiring harness or an internal failure within the switch itself.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430
• 7430
• 7530

1. 1

   Inspect the wiring harness (specifically lead 6046) for any open connections, chafing, or short circuits to a positive lead

2. 2

   Inspect all connectors associated with the clutch pedal switch (S72) for signs of physical damage, loose pins, or corrosion

3. 3

   Verify that the switch and its circuitry are properly grounded, as bad grounds can cause voltage irregularities

4. 4

   Use a multimeter to measure the voltage output at the signal lead of the clutch pedal switch to determine if it has failed internally

1. 1

   Power Down

   Turn off the ignition and disconnect the battery to ensure safety while working on the electrical system.

2. 2

   Locate the Switch

   Locate the clutch pedal switch (S72) on the clutch pedal linkage/assembly inside the cab.

3. 3

   Wiring Repair (If Applicable)

   If the diagnostic checks revealed a short to power or a broken wire in the harness, repair the damaged section of the wiring or replace the connector pigtail.

4. 4

   Remove the Faulty Switch

   If the wiring is intact but the switch failed the multimeter test, disconnect the 3-pin electrical connector from the switch. Unbolt or unclip the switch from its mounting bracket.

5. 5

   Install the New Switch

   Mount the replacement OEM clutch pedal switch. Ensure it is properly aligned with the pedal mechanism so that it accurately detects the pedal's resting and depressed positions.

6. 6

   Reconnect and Calibrate

   Reconnect the electrical plug and reconnect the battery. Turn the ignition ON to allow the control unit boot sequence to initialize.

7. 7

   Test Operation

   Clear the stored 000598.03 fault code using a diagnostic tool. Depress the clutch pedal to ensure the transmission engages/disengages properly and verify that the code does not return.