The throttle control on Volvo excavators usually involves mechanical throttle, electronic throttle (ECU/e-throttle), pedal or knob, sensors, and linkage. Faults may cause unstable engine idle, slow response, or inability to accelerate.

1. Slow Throttle Response or Engine RPM Not Increasing

• Possible Causes

  • Throttle pedal or knob sticking

  • Throttle cable or linkage worn or loose

  • Electronic throttle sensor failure

  • Engine control module (ECM) software error or malfunction

• Remedies

  • Check pedal or knob for smooth operation → clean, lubricate, or replace

  • Inspect throttle cable and linkage → adjust or replace

  • Test throttle sensor voltage/signals → repair or replace

  • Reset or update ECM software; replace module if necessary

2. Unstable Idle or Engine Vibration

• Possible Causes

  • Idle air control valve (IAC) clogged or damaged

  • Throttle sensor signal drift

  • Intake leaks or carbon buildup on throttle plate

• Remedies

  • Clean or replace idle control valve

  • Calibrate or replace throttle sensor

  • Inspect intake system for leaks and clean throttle plate

3. Throttle Stuck or Not Returning

• Possible Causes

  • Pedal sticking or spring failure

  • Throttle cable or linkage rusted/worn

  • Electronic throttle actuator failure

• Remedies

  • Clean pedal, lubricate or replace spring

  • Inspect throttle cable and linkage → replace if necessary

  • Test electronic throttle actuator, replace if faulty

4. Throttle Switch/Button Malfunction (Electronic Control)

• Possible Causes

  • Throttle switch damaged or contact failure

  • ECU signal reception abnormal

• Remedies

  • Replace throttle switch

  • Check wiring and ECU communication

  • Reset or replace ECU if needed

Maintenance and Prevention

1. Regularly inspect throttle pedal, knob, and spring to ensure smooth operation.

2. Keep throttle cable and linkage lubricated to prevent wear and rust.

3. Regularly check electronic throttle sensors and actuators to avoid signal drift.

4. Clean throttle plate and intake system to maintain proper airflow.

5. Address throttle response issues promptly to prevent engine overload or unstable operation.