What causes the yellow engine light to come on in a truck?
2 Answers
The yellow engine light in a truck can come on for many reasons, mainly including excessive engine temperature, engine misfire, severe engine carbon buildup, and poor fuel quality. When the yellow engine light comes on, the vehicle may experience symptoms such as sluggish acceleration and abnormal engine vibration. In such cases, it is important to pull over immediately and conduct an inspection to prevent potential safety hazards. Excessive engine temperature: When a vehicle undergoes aggressive driving, the engine may operate under excessive load, leading to overheating. In this situation, the yellow engine light will illuminate to alert the driver to shut off the engine and allow it to cool down naturally. Engine misfire: When an engine misfires, the vehicle may exhibit abnormal body vibrations and a significant reduction in power. In such cases, it is necessary to visit a repair shop or a 4S store for a professional inspection. Severe engine carbon buildup: Severe carbon buildup in the engine can interfere with normal fuel combustion, leading to reduced power. In such cases, it is important to clean the engine carbon deposits promptly. Poor fuel quality: Low-quality fuel can also cause the yellow engine light to come on. In this situation, it is necessary to replace the fuel with a higher-quality alternative.
This yellow engine light, I call it 'the truck throwing a tantrum'. After driving semi-trailers for over a decade, I've seen it too often. Most commonly, it's the aftertreatment system acting up - either the urea injector getting clogged from overuse in China V/VI trucks, or the particulate filter getting blocked and struggling to breathe. If you don't change the diesel filter for three months, it'll light up to remind you. Just last week, I helped Old Zhang replace his diesel filter, and the light went out immediately. If the exhaust smells particularly pungent, there's an 80% chance the waste gas pipe is leaking. Oh, and after highway driving, listen for a 'hissing' sound when shutting off - that's the DPF doing its self-cleaning. Don't push through it - one of my fleet guys drove 300 km with it on and ended up with an 8,000 yuan repair bill. Check these two things first, and you'll solve 80% of the cases!
