What Causes the Activation of the Whole Vehicle Performance Limitation Function in Diesel Vehicles?
2 Answers
Diesel vehicles displaying the activation of the whole vehicle performance limitation function are primarily caused by incorrect ignition timing, low fuel pressure, air intake system leaks, faults in the throttle position sensor or air flow meter, poor injector performance, or malfunctioning EGR system. Below are the relevant details: Ignition Timing: The angle through which the crankshaft rotates from the moment of ignition until the piston reaches the top dead center of compression. The ignition timing that allows the engine to achieve optimal power, fuel efficiency, and emissions is referred to as the optimal ignition timing. Factors Affecting Ignition Timing The most significant factors affecting ignition timing are engine speed and the combustion speed of the air-fuel mixture. As engine speed increases, the time taken to rotate through the same angle decreases, requiring a larger advance angle to achieve the corresponding advance time. The combustion speed of the air-fuel mixture is influenced by the mixture's composition, engine design, and other factors such as combustion chamber shape and compression ratio.
Recently, my diesel vehicle also had this warning light illuminated, which indicates the intervention of the vehicle's protection system, usually due to detecting potential faults to prevent more severe damage. The main causes include exhaust system blockage, such as a full Diesel Particulate Filter (DPF) requiring regeneration or carbon buildup in the EGR valve causing airflow obstruction; engine sensors may report errors, like pressure sensors detecting insufficient fuel supply or turbocharger issues; additionally, oxidized electrical connectors, degraded fuel pump performance, or abnormal air-fuel ratios can also trigger the limitation function. The car may feel sluggish during acceleration and have difficulty saving fuel. I recommend immediately using an OBD scanner to read the fault codes and avoid long-distance driving under these conditions. After inspection, clean or replace the relevant components to avoid higher engine repair costs later. Generally, authorized dealerships can professionally handle this issue, and it's important to develop a habit of checking the DPF during regular maintenance.