Case IH 4197 – DU Module: Rear EHR No.4 Motor Mode Switch Faulty (DU module only)

Malfunction in the program/motor mode switch circuit for the #4 rear Electronic Hydraulic Remote (EHR) valve. The system has detected an implausible signal, open circuit, or short circuit from this specific switch.

• Maxxum
• Case IH Puma Series
• Case IH Magnum Series
• Case IH Maxxum Series
• Case IH Steiger Series

1. 1

   Check the CAN BUS wiring harness between the rear remote valves and the central controller (DU module) for chafed wires, corrosion, or loose pins at the EHR #4 connector.

2. 2

   Enter the tractor's 'H' (Diagnostic) menu and navigate to the switch test screen (identifier d98). Actuate the switch and perform a wiggle test on the wiring harness to see if the connection drops.

3. 3

   Inspect the EHR valve's internal diagnostic LED (may require scraping paint on the plastic casing) and count flash sequences to cross-reference localized valve hardware errors.

4. 4

   Verify if the software in the central controller needs to be reloaded before condemning the hardware, especially if wiring is intact but valves remain inoperative.

1. 1

   Power Down

   Turn off the tractor and turn the battery disconnect switch to the OFF position.

2. 2

   Access the Valve Stack

   Locate the rear EHR valve stack. Identify valve #4 (valves are numbered sequentially; verify your specific stack layout).

3. 3

   Inspect/Clean Connectors

   Disconnect the electrical harness from EHR valve #4. Clean the contacts with electrical contact cleaner and apply dielectric grease. Reconnect and test.

4. 4

   Replace the Switch/Valve Head

   If the switch itself (often integrated into the EHR electronic control head or the armrest control) is internally shorted/open, the faulty component must be replaced. In many Case IH CCLS hydraulic systems, the electronic actuator head on the spool valve is replaced as a single unit.

5. 5

   EHR Renumbering Procedure

   If the EHR valve or electronic head is replaced, you must perform the EHR valve renumbering procedure via the Control Module configuration menu to prevent sequence errors (e.g., U160/U161).

6. 6

   Clear Codes

   Clear the EEPROM fault codes using the H8 menu or an Electronic Service Tool (EST) and verify operation.