New Holland ENG 3144 – Engine Control Module (ECM): Grid Heater Switch Off Test (Voltage Drop Too Low)

This fault code indicates a problem with the intake air grid heater circuit. When the Engine Control Module (ECM) commands the grid heater off and runs a diagnostic test, it measures the voltage drop across the circuit. A "Voltage Drop Too Low" reading means the circuit is not drawing the expected electrical current. This typically points to an open circuit, a blown high-amp fuse, a failed grid heater relay (solenoid), or a burnt-out grid heater element.

• T8 series
• T9020
• TJ330
• TS115A
• T6030
• CR9090
• CX8080
• CX8090 Elevation Tier 4A
• L180
• L230
• LT185.B
• B90B
• B100B
• B110B
• B115B

1. 1

   Inspect the main grid heater fuse (often a 200A inline fuse or designated as F21). If blown, check the heavy-gauge wiring for a short to ground.

2. 2

   Clean the battery posts and verify the chassis ground connections are tight and free of corrosion.

3. 3

   Test the grid heater power relay. Check for heavily corroded terminals, test if the relay coil has continuity, and verify that the internal contacts close when power is applied.

4. 4

   Disconnect the power cable at the intake manifold grid heater and use a multimeter to measure the resistance of the element to ground. An infinite reading (OL) means the heater element is broken/open.

5. 5

   Verify via the H3 configuration menu (on applicable models like TS115A) that the grid heater is enabled in the software, otherwise the ECM will not operate it.

1. 1

   Disconnect Power

   Disconnect the negative battery cable. The grid heater circuit is wired directly to the battery and carries high amperage; working on it live poses a severe short-circuit and fire risk.

2. 2

   Access the Components

   Locate the grid heater power relay (usually mounted near the fuse block or engine firewall) and the grid heater element (sandwiched in the air intake manifold piping).

3. 3

   Clean Connections

   Remove the heavy-gauge cables from the relay and the heater element. Clean all ring terminals with a wire brush. Reinstall if corrosion was the only issue.

4. 4

   Replace the Relay (If Faulty)

   Unbolt the relay from its mounting bracket, disconnect the ECM trigger wires, and install the new relay. Torque the heavy-gauge cable nuts to OEM spec to prevent arcing.

5. 5

   Replace the Grid Heater Element (If Faulty)

   Remove the intake air piping connected to the grid heater. Unbolt the grid heater block from the intake manifold. Scrape away any old gasket material from the mating surfaces. Install the new grid heater element using new gaskets. Reattach the intake piping and the heavy-gauge power cable.

6. 6

   Reassemble and Clear Codes

   Reconnect the negative battery cable. Turn the ignition key to the ON position in cold weather to verify the grid heater indicator light illuminates. Use a CNH Electronic Service Tool (EST) to clear the ENG 3144 fault code.