CLAAS 7890h: Invalid or Missing Engine Speed Signal from External Function Module

The external function module EXT is not receiving valid engine speed information from the engine or is not receiving any information for more than 5 seconds. This may affect the proper operation of systems dependent on engine speed data.

1. 1

   The connection between the engine and the external function module EXT

2. 2

   The signal path from the engine to the external function module EXT

3. 3

   The integrity of the Bus CAN communication

1. 1

   Inspect

   Inspect the wiring and connectors between the engine and the external function module EXT for damage, corrosion, or loose connections.

2. 2

   Test

   Test the Bus CAN communication for signal integrity and proper data transmission between the engine and the external function module EXT.

3. 3

   Verify

   Verify that the engine is sending a valid speed signal and that the external function module EXT is receiving and processing it correctly.