John Deere 523974.02 – SFA / TSC: Axle Pressure Sensor Detected Incorrect Pressure In The Front Axle Circuit

Triggered during the Triple-Link Suspension (TLS) oil pressure sensor check. The controller detects an incorrect change in pressure (a reduction when an increase was commanded, or vice versa), indicating a failure in pressure regulation which can compromise vehicle stability and front-axle suspension operation.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6230
• 6330
• 6430
• 8310RT
• 8335RT
• 8360RT

1. 1

   Inspect the TLS Pressure Sensor (B167) signal output to ensure it is operating within the expected voltage range, and check the wiring harness and connectors for corrosion, damage, or loose pins.

2. 2

   Check the front axle hydraulic circuit for blockages, internal leaks, or signs of incorrect pressure changes, ensuring the system provides accurate base pressure.

3. 3

   Verify the functionality of the TLS solenoid valves (Y66, Y67, Y68, Y69) to ensure they are actuating correctly and are not stuck open or closed.

4. 4

   Attempt to recalibrate the TLS system using the John Deere Service ADVISOR tool to see if the sensor can successfully complete its pressure test.

1. 1

   Relieve Hydraulic Pressure

   Before opening the hydraulic circuit, safely relieve all pressure in the TLS front-wheel drive axle hydraulic system.

2. 2

   Repair Wiring/Connectors

   If the diagnostic checks revealed a short or open circuit in the B167 sensor harness, repair the wiring or replace the connector pigtail.

3. 3

   Replace Faulty Components

   If the B167 sensor failed the output test, unthread the old sensor from the TLS control block and install the new sensor. If a solenoid valve (pressure build-up or reduction) was found to be sticking, replace the faulty solenoid cartridge on the TLS valve block.

4. 4

   Bleed the System

   Bleed the air from the TLS hydraulic system.

5. 5

   Recalibrate

   Connect the diagnostic tool and run the TLS calibration procedure to ensure the new sensor or valve is recognized and the pressure test passes without logging 523974.02.