John Deere 186.04 – PTF: Front PTO speed sensor, Voltage too low

Triggered when the control software registers that the voltage at the output of the front PTO speed sensor has dropped below the acceptable threshold. This typically indicates a short to ground, a failed sensor, or a wiring harness issue.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC

1. 1

   Inspect the front PTO speed sensor wiring harness for any signs of damage, chafing, or disconnected wires that could cause a voltage drop or short to ground.

2. 2

   Ensure that all connectors between the sensor and the PTF module are properly seated. Inspect the pins for corrosion, moisture, or debris, which can cause high resistance and low voltage readings.

3. 3

   Use a multimeter or John Deere diagnostic tools to verify the functionality and voltage output of the front PTO speed sensor.

1. 1

   Access the Sensor

   Locate the front PTO speed sensor on the front PTO housing.

2. 2

   Clean and Reconnect

   If corrosion or a loose connection was found during diagnostics, clean the connector pins thoroughly, apply dielectric grease, and securely reconnect the harness.

3. 3

   Repair Wiring

   If the wiring harness is damaged or shorting out against the chassis, repair or splice the damaged section of the wire, or replace the harness section if heavily damaged.

4. 4

   Replace the Sensor

   If diagnostic testing proves the sensor itself has failed internally (causing the low voltage reading), remove the faulty sensor and install a new OEM replacement.

5. 5

   Clear Codes

   Clear the PTF 000186.04 code from the system and run the front PTO to ensure reliable operation and verify the code does not return.