New Holland ENG 227 – ENGINE (ECM) Controller: Sensor Supply 2 Voltage is too high

The ECM detects that the voltage on the 'Sensor Supply 2' circuit is out of range high. This is typically caused by the 5-volt supply wire shorting to a higher voltage source (such as a 12V battery line) in the wiring harness, a shorted sensor, or an internal failure within the ECM.

• T8 Series
• T9 Series
• T9000 Series
• TM 175
• TS100
• CR9090
• CX8080 Elevation
• CX8090 Elevation
• MX Magnum series

1. 1

   Visually inspect the engine wiring harness and connectors for chafing, rubbing, or pinched wires that could cause the 5-volt supply wire to short against a 12-volt battery source, especially where zip-tied to the engine block.

2. 2

   Perform a Sensor Isolation Test: Turn keyswitch ON, disconnect sensors on the Sensor Supply 2 circuit one at a time, and monitor fault code status. If it becomes inactive, the unplugged sensor is internally shorted.

3. 3

   Perform an ECM Voltage Check: Disconnect the engine harness from the ECM and measure voltage at the Sensor Supply 2 pins directly on the ECM. Output significantly above 5 volts indicates internal ECM failure.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery terminal before repairing wiring or replacing the ECM.

2. 2

   Repair/Replace Wiring

   If a short to battery voltage was found during the harness inspection, repair the damaged wires using approved splicing techniques and heat shrink, or replace the affected harness section. Ensure the harness is routed away from sharp edges and high-heat sources.

3. 3

   Replace Faulty Sensor

   If the isolation test identified a shorted sensor (e.g., Intake Manifold Pressure Sensor), remove the faulty sensor and install a new OEM replacement. Torque to the manufacturer's specifications.

4. 4

   Replace the ECM

   If the ECM itself is outputting high voltage, it must be replaced and flashed with the correct calibration software for the specific machine.

5. 5

   Validate the Repair

   Reconnect all sensors and batteries. Turn the keyswitch ON, start the engine, and let it idle for at least 1 minute. Verify that the amber warning lamp turns off and the fault code status changes to INACTIVE in the diagnostic tool. Clear the inactive codes.