New Holland ENG 349 – Engine Control Module (ECM): Measured Speed is too high

The Engine Control Module (ECM) has detected an auxiliary speed sensor frequency that is above the OEM-defined limit. This is typically caused by a high-frequency input into the external speed command input circuit, resulting in an engine power derate and an illuminated amber CHECK ENGINE lamp.

• T8040
• TG210
• TG230
• TG255
• TG285
• T7 series
• TM series
• CR9090
• CX8080 Elevation
• CX8090 Elevation Tier 4A
• Magnum
• MX series

1. 1

   Inspect the external speed command input circuit and wiring harness for shorts, chafing, or electrical interference.

2. 2

   Check the auxiliary speed sensor / transmission output shaft speed sensor and its connector for loose pins, corrosion, or physical damage.

3. 3

   If diagnosing the engine speed sensor on an 8.3L CAPS engine, check the tone wheel on the cam gear for excessive runout using a dial indicator (runout exceeding .002 inches can cause erratic speed sensor readings).

1. 1

   Locate the sensor

   Find the auxiliary speed governor/sensor (refer to the specific machine's service manual for exact location).

2. 2

   Repair wiring

   Repair any damaged wiring in the speed command input circuit.

3. 3

   Replace the speed sensor

   If the wiring is intact but the frequency reading remains out of range, replace the faulty speed sensor.

4. 4

   Clear the fault code

   Start the engine and let it idle for 1 minute to validate the repair and change the fault code status to INACTIVE, or use the 'Reset All Faults' command in the recommended electronic service tool.