Case IH 17670 (F-3695-02) - ECU – ECU: Manual catalyst management CAN activation signal from display/cluster is incorrect or not plausible

The Engine Control Unit is receiving an invalid, incorrect, or illogical Controller Area Network (CAN) signal from the instrument cluster or display regarding the manual catalyst management system (manual DPF regeneration or regen inhibit switch).

• VESTRUM CVX
• Farmall 40
• Farmall 45
• Farmall 50
• Farmall 85A
• Farmall 95A
• Farmall 105A
• Farmall 115A
• Farmall 85C
• Farmall 95C
• Farmall 105C
• Farmall 95U
• Farmall 105U
• Farmall 115U
• Optum 270 CVT

1. 1

   Verify that the tractor meets all conditions for manual regeneration: engine running, machine stationary, hand brake engaged, hand throttle at minimum, foot throttle released, PTO disengaged, and hydraulic system inactive.

2. 2

   Check the physical condition of the manual DPF regeneration / regen inhibit button on the display or cluster to ensure it is not physically stuck or damaged.

3. 3

   Inspect the diagnostics connections and wiring harnesses between the display/cluster (CCM - Cab Control Module) and the Engine ECU for loose connections, corrosion, or wiring damage.

1. 1

   Access the Cab Control Module (CCM) / Display

   Gain access to the rear of the instrument cluster or display where the manual catalyst management switch is housed.

2. 2

   Test the Wiring

   Use a multimeter to test the CAN bus wiring continuity between the cluster/display harness and the ECU pins. Repair any broken or shorted wires.

3. 3

   Replace the Faulty Component

   If the wiring is intact, the implausible signal is likely originating from a failed internal switch contact or a fault within the display/cluster's CAN transceiver. Replace the switch (if serviceable independently) or the cluster assembly.

4. 4

   Clear Codes and Calibrate

   Reconnect the system and use a diagnostic tool (such as the Case IH EST or a compatible tool like Jaltest) to clear the ECU fault codes.

5. 5

   Test Operation

   Start the tractor, set the required stationary parameters (parking brake on, PTO off, etc.), and press the manual regen button to verify the ECU receives a plausible signal and initiates (or inhibits) the cycle properly.