CLAAS Id788Dh / 788Dh – EXT (A62): CAN bus communication timeout related to the rear hitch/lifting system

The external function module has not received the rear lifting status information for more than 5 seconds over the CLAAS vehicle CAN bus. As a result, the 'lifting high position' information is not available on the 7-pin ISO connector.

• Axion 800 series (810, 850)
• Axion 900 series (920, 950)
• Arion 500/600 series (510, 640)

1. 1

   Check the CLAAS vehicle CAN bus network for physical damage, open circuits, or short-circuits (to ground or 12V)

2. 2

   Inspect the 7-pin ISO implement connector at the rear of the tractor for corrosion, moisture, or pushed-out pins

3. 3

   Verify the BDG (A103) CAN network communication module is functioning and relaying messages properly

4. 4

   Verify the REH (A058) rear lifting module is operating and transmitting its status

1. 1

   Visual Inspection

   Inspect the 7-pin ISO connector at the rear of the tractor. Clean the contacts with electrical contact cleaner if corrosion is present.

2. 2

   Wiring & Voltage Test

   Test the energy sources for the EXT (A62), BDG (A103), and REH (A058) modules. Ensure all related fuses are intact and that the modules have proper power and ground.

3. 3

   CAN Bus Continuity Test

   Using a multimeter, check the CAN bus wiring harness between the REH lifting module, the BDG communication module, and the EXT module for continuity. Repair any broken wires or chafed harnesses.

4. 4

   Software/Calibration Verification

   Check the compatibility of the program versions, settings, and calibration of the modules via the CLAAS diagnostic tool (CDS).

5. 5

   Component Replacement

   If the wiring, power, and grounds are all within specification, replace the faulty module (most likely the EXT A62 or REH A058 module failing to send/receive the signal).