New Holland ENG 3352 – Engine Controller: Engine Brake Decompression Valve - Short-circuit to Battery

This fault code indicates that the engine control module has detected an unexpectedly high voltage on the circuit controlling the engine brake decompression valve. This typically means the control wire is shorted directly to a battery power source, preventing the ECU from properly regulating the valve.

• T8.xxx Series
• CR9090
• CX8080 Elevation
• CX8090 Elevation
• Magnum 235 - 340 (Series 4)

1. 1

   Check 'Main Relay 1' or 'Main Relay 4' (Engine Brake Exhaust Valve Relay) for internal shorts to battery

2. 2

   Inspect the wiring harness running from the Engine ECU to the Engine Brake Decompression Valve for chafing, melted insulation, or pinched wires

3. 3

   Disconnect the harness at the decompression valve and check for corrosion, water ingress, or bent pins

4. 4

   With the key ON and the valve disconnected, use a multimeter to probe the control wire on the harness side for battery voltage (approx. 12V)

5. 5

   Measure the internal resistance of the Engine Brake Decompression Valve solenoid to ensure it has not failed internally

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery terminal to prevent electrical damage during testing.

2. 2

   Isolate the Circuit

   Disconnect the wiring harness from both the Engine ECU and the Engine Brake Decompression Valve.

3. 3

   Trace the Short

   Using a multimeter set to continuity/ohms, test the valve's control wire against the battery positive cable.

4. 4

   Repair the Harness

   If continuity is found, trace the harness to locate the short. Repair the damaged section of the wire using heat-shrink butt connectors and re-loom the harness, or replace the engine harness section if the damage is extensive.

5. 5

   Replace the Valve

   If the wiring harness tests perfectly fine and the short is isolated to the valve itself, remove the retaining bolts for the Engine Brake Decompression Valve, remove the faulty unit, and install the replacement valve.

6. 6

   Reassemble and Clear Codes

   Reconnect all harnesses and the battery. Use a CNH Electronic Service Tool (EST) to clear the inactive ENG 3352 fault code. Run the engine and engage the engine brake to verify the repair.