Anyone who has ever dealt with a modern vehicle has probably come across the term “Held Full Speed”. But what does that actually mean? And how do you, as a car mechanic, deal with it?
In this article, we shed light on the meaning of “Held Full Speed”, explain the possible causes, and show you how to solve this problem using diagnostic tools and your expertise.
What does “Held Full Speed” actually mean?
“Held Full Speed” essentially means that your vehicle’s engine control unit (ECU) is constantly maintaining speed, even though the driver has actually taken their foot off the accelerator pedal. The vehicle behaves as if the accelerator pedal is permanently depressed.
Imagine you’re driving on the highway and take your foot off the gas pedal to slow down. But instead of slowing down, your vehicle maintains speed. Sounds scary, right? That’s exactly what can happen when your vehicle reports a “Held Full Speed” error.
Why does the “Held Full Speed” error occur?
There are several reasons why a vehicle might report a “Held Full Speed” error. Here are some of the most common causes:
- Defective Throttle Position Sensor: The throttle position sensor measures the position of the throttle valve and relays this information to the engine control unit. If the sensor is defective, it can happen that the engine control unit receives incorrect information and the vehicle therefore no longer responds correctly to the accelerator pedal commands.
- Faulty Engine Control Unit: In rare cases, a defective engine control unit can also be the cause of the “Held Full Speed” error. In this case, the engine control unit must be repaired or replaced.
- Wiring Issues: A short circuit or interruption in the wiring of the throttle position sensor or the engine control unit can also lead to the “Held Full Speed” error.
- Software Error: Modern vehicles are equipped with complex software. An error in the software of the engine control unit can also cause the vehicle to no longer respond correctly to the accelerator pedal commands.
Diagnosis and Troubleshooting of “Held Full Speed”
Diagnosing and troubleshooting the “Held Full Speed” error requires the use of a diagnostic tool and sound knowledge of vehicle technology.
Here are some steps you can take:
- Connect Diagnostic Tool: Connect a diagnostic tool to the vehicle’s OBD-II interface and read out the error codes.
- Analyze Error Codes: Analyze the error codes and research their meaning. In the case of “Held Full Speed”, you will probably find error codes that point to the throttle position sensor or the engine control unit.
- Check Throttle Position Sensor: Check the throttle position sensor for damage and wear. Measure the resistance of the sensor and compare it with the manufacturer’s specifications.
- Check Wiring: Check the wiring of the throttle position sensor and the engine control unit for damage, short circuits, and interruptions.
- Check Engine Control Unit: If the throttle position sensor and the wiring are okay, the engine control unit may be defective. In this case, you should contact a specialist who can check the engine control unit and repair or replace it if necessary.
