John Deere 002003.09 – ICU / ACU / SFA: CAN Bus Communication Error (PTP/PTI)

This fault code indicates a communication error on the Controller Area Network (CAN bus). Specifically, a required message from the Powershift Transmission Control Unit (PTP) or Transmission Control Unit (PTI) is not being received by other control modules on the network, such as the Instrument Control Unit (ICU), Armrest Control Unit (ACU), or Suspended Front Axle (SFA) Control Unit. This loss of communication can lead to various operational symptoms, most notably the machine being unable to move.

• 3033R
• 4044M
• 4310
• 5075E
• 7530
• 7630
• 7715
• 7730
• 7815
• 7830
• 7930
• 8130
• 8230
• 8330
• 8430
• 8530
• 9230
• 9330
• 9430
• 9530
• 9630
• S670
• S680
• T560
• T660
• T670
• W650
• W660
• 7180
• 7280
• 7380
• 7480
• 7580
• 7780

1. 1

   Check relevant fuses (e.g., F6 or F35 on 7715/7815 tractors, F24 for ECU messages, or F30 for SFA faults) depending on your specific model and transmission type

2. 2

   Visually inspect wiring harnesses and connectors between the transmission controller (PTP/PTI) and the logging controller (ICU/ACU) for chafing, pinching, or rodent damage

3. 3

   Inspect rectangular connectors (often located under the operator's seat on the right-hand side) for water accumulation and corrosion

4. 4

   Check ground straps from the battery to the chassis to ensure they are clean and tight

5. 5

   Perform a CAN Bus Health Check (Power Off) by measuring resistance between CAN High and CAN Low at the 9-pin diagnostic connector (measuring between pins C and D). A reading of approximately 60 Ω is healthy; 120 Ω suggests a missing resistor or open circuit, and significantly less than 60 Ω indicates a short or extra resistor

6. 6

   Perform a CAN Bus Voltage Check (Power On) by turning the key to the 'ON' position (engine off) and measuring voltage between CAN lines and chassis ground (CAN High should be 2.5-3.5V; CAN Low should be 1.5-2.5V)

1. 1

   Restart the machine

   Restart the tractor to determine if the fault is intermittent. If the code clears and does not return, no further action is needed. If it returns, proceed to the next step.

2. 2

   Replace fuses and repair wiring

   Replace any blown fuses found during inspection. If a fuse blows again immediately, locate and repair the short circuit in that protected wiring. Clean or replace any corroded connectors and repair damaged harness sections.

3. 3

   Address CAN bus faults

   If CAN bus resistance is 120 Ω or open, locate the terminating resistors (usually one at the front and one at the rear) and ensure they are connected. If CAN voltages are incorrect, isolate controllers one by one by unplugging them from the CAN bus and re-checking voltages. The last controller unplugged before the voltage normalizes is likely the faulty component.

4. 4

   Replace faulty controller

   If a specific controller (such as the PTP or PTI) is identified as the source of the fault by isolating it from the CAN bus, replace the controller assembly.