New Holland 3126 – Engine Control Unit (ECU) or Armrest control unit: Throttle Lever - Channel 1 Signal Above the Set Range

The Engine Control Unit (ECU) has detected a voltage signal from the hand throttle's channel 1 potentiometer that is above the maximum expected threshold. This typically indicates an open circuit or an internal fault within the sensor itself. As a result, the machine's speed control system is affected, leading to a loss of throttle control where the engine may default to a preset speed or become unresponsive to lever movements.

• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• TL70
• TL80
• TL90
• TL100
• TM115
• TM120
• TM125
• TM130
• TM135
• TM140
• TM150
• TM155
• TM165
• TS90
• TS100
• TS110
• TS115
• TS100A
• TS110A
• TS115A
• TS135A
• FR9040
• FR9050
• FR9060
• FR9080
• FR9090
• 8670
• 8770
• 8870
• 8970

1. 1

   Visually inspect the wiring harness between the hand throttle assembly and the ECU for chafing, corrosion on connectors, or loose pins

2. 2

   Check for other related fault codes (such as code 227 for sensor supply voltage high) which could indicate a broader electrical issue rather than an isolated sensor failure

3. 3

   Disconnect the throttle position sensor and measure the total resistance between the two outer terminals to ensure it matches specifications

4. 4

   Test the potentiometer wiper signal by measuring resistance between the center terminal and an outer terminal while moving the throttle lever; the reading should change smoothly without erratic jumps

5. 5

   If accessible while connected, back-probe to perform a voltage test verifying the 5V reference, ground, and signal wire (which should vary smoothly from under 1V at idle to up to 4.5V at full throttle)

1. 1

   Confirm the fault

   Follow the diagnostic checks to confirm that the hand throttle potentiometer is the source of the fault.

2. 2

   Isolate and disconnect power

   Ensure the machine is turned off and the battery is disconnected to prevent electrical damage before beginning repairs.

3. 3

   Access the component

   Remove necessary panels or covers in the cab or on the armrest console to access the hand throttle assembly.

4. 4

   Replace the potentiometer

   Disconnect the electrical connector, mechanically remove the faulty potentiometer (noting its orientation), install the new sensor with correct alignment, and reconnect the wiring.

5. 5

   Reassemble and test

   Reassemble panels, reconnect the battery, turn the machine on to verify the fault code has cleared, and operate the hand throttle to ensure correct engine response.

6. 6

   Calibrate the new sensor

   If required by your specific model, put the controller into calibration mode and move the throttle lever to its minimum and maximum positions to teach the ECU the new sensor's range.