John Deere 000191.17 – Main Control Module (PTR, PTQ, EPC, or PTP): Transmission Speed Sensor Speed Is Too Low

The Main Control Module has detected that the transmission's output shaft speed is below the expected operational range or is completely absent when vehicle movement is expected. This condition is logged when the tractor's control unit commands a forward or reverse movement but does not receive a corresponding speed signal from the transmission speed sensor. As a protective measure, the tractor may move a short distance and then stop, or it may automatically shift into neutral.

• 5045E
• 5055E
• 5065E
• 5075E
• 5085E
• 5090E
• 5090EL
• 5100E
• 6105E
• 5065M
• 5075M
• 5085M
• 5095M
• 5095MH
• 5105M
• 5015ML
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5080R
• 5090R
• 5100R
• 6010
• 6110
• 6120
• 6200
• 6210
• 6215
• 6220
• 6300
• 6310
• 6320
• 6330
• 6400
• 6405
• 6410
• 6415
• 6430
• 6500
• 6605
• 6715
• 6140R
• 7220
• 7320
• 7420
• 7520

1. 1

   Scan all control units for other active or stored fault codes (CAN bus communication errors or faults related to the neutral/seat switches can sometimes trigger this code)

2. 2

   Inspect the transmission and hydraulic oil level and condition, and check the transmission filter or suction screen for metal debris indicating internal wear

3. 3

   Visually inspect the wiring harness and connectors leading to the transmission speed sensor for fraying, melting, corrosion, pushed-back pins, or poor ground connections

4. 4

   Locate the transmission speed sensor (generally on the transmission housing, top of the range box, or left side; some models require removing the right rear wheel for access) and test its resistance using a multimeter (e.g., on a 6140R, resistance between pins A and C should be approximately 3300 ohms; 'OL' indicates a faulty sensor)

5. 5

   Test the harness-side voltage with the key on (e.g., on a 6140R, pin C should have a 12V supply and pin D should have good continuity to ground)

6. 6

   Perform a hydraulic pressure test at a rear remote or dedicated transmission test port to check for internal mechanical issues like clutch slippage (general standby pressure is typically 2250-2350 PSI)

1. 1

   Address electrical issues

   If damaged wiring, corroded connectors, or bad grounds are found during inspection, repair or replace the affected components. If a fuse is blown, identify and rectify the short circuit before replacing the fuse.

2. 2

   Replace the transmission speed sensor

   If the sensor fails the resistance or voltage tests, unbolt the old sensor, ensure the mounting surface is clean, and install the new sensor utilizing a new O-ring.

3. 3

   Perform clutch calibration

   On models with a power reverser or electronic transmission, perform a clutch or transmission calibration using John Deere Service Advisor software. This is necessary after repairs or can resolve issues related to clutch fill times.

4. 4

   Address mechanical failures

   If diagnostics point to internal hydraulic pressure loss or mechanical slippage, the transmission will need to be disassembled by a qualified technician for inspection and repair of worn or damaged clutches or seals.