John Deere 2020.09 – TIQ, ACU, ICU, or PTP: Incorrect CAN BUS message, Information from SFA control software / SFA Message Missing

Communication network error indicating a breakdown on the CAN Bus where the reporting module is not receiving expected data packets from the SFA (Suspension Front Axle) control unit. Symptoms include restricted top forward/reverse gears or disabled front axle suspension features.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6090MC
• 6090RC
• 6100MC
• 6100RC
• 6110MC
• 6110RC
• 7210R
• 7290R
• 6010
• 7010
• 7810
• 8430

1. 1

   Check fuses F24, F30, F22, or F23 (consult operator manual for exact SFA/Cab fuse location) for a blown power supply fuse

2. 2

   Perform a soft reset of the control modules by cycling the tractor's power to clear any transient voltage errors

3. 3

   Inspect the CAN bus wiring and connectors between the TIQ/CAB module and the SFA module for physical damage, pinched wires, or loose connections

4. 4

   Perform a continuity test using a multimeter or diagnostic tool to trace CAN bus lines, checking for shorts to ground or terminating resistor failures

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes.

2. 2

   Fuse Replacement

   If the SFA fuse (e.g., F24/F30) is blown, replace it. If it blows again immediately upon startup, there is a dead short in the SFA wiring or the module itself.

3. 3

   Harness Repair

   Disconnect the wiring harness at the SFA control unit. Inspect the pins for corrosion, moisture ingress, or push-back. If the CAN High or CAN Low wires are damaged, splice and repair the segments using OEM-grade weather-sealed connectors.

4. 4

   Module Testing

   If the wiring has perfect continuity and the fuses are intact, the SFA control unit has likely failed internally and is no longer broadcasting on the network.

5. 5

   Replacement & Calibration

   Replace the SFA control unit. A new or remanufactured SFA module must be calibrated to the tractor using John Deere dealer software (Service Advisor) before it will function correctly.