What does it mean when the DEF light is on in a JMC diesel vehicle?
2 Answers
JMC diesel vehicle DEF light on indicates a shortage of diesel exhaust fluid (DEF), reminding the owner to replenish it promptly. Insufficient or non-use of DEF can affect the vehicle's power and exhaust emissions. DEF is a liquid used in SCR technology to reduce nitrogen oxide pollution in diesel vehicle exhaust, composed of 32.5% high-purity urea and 67.5% deionized water. Taking the JMC Transit 2020 2.8T Business Long Wheelbase Mid-Roof 9-Seater National V JX493 as an example: it is a light passenger vehicle introduced by JMC Motors, with dimensions of 5696mm in length, 1972mm in width, and 2240mm in height, equipped with a 2.8T turbocharged engine delivering a maximum power of 85kw, paired with a 5-speed manual transmission.
Last time I drove my JMC diesel truck, the DEF warning light suddenly came on, which gave me a real scare. I know DEF stands for Diesel Exhaust Fluid, specifically used to clean the emission system. The most common reason for the light is low fluid level in the tank, meaning it needs a refill. If not topped up in time, the vehicle might enter a speed-limiting mode, making it feel like driving with tied feet – super frustrating. My usual routine is to pull into a gas station, open the filler cap under the trunk, and pour in DEF fluid with 32.5% concentration until full, then the light goes off. But if the light stays on after refilling, the issue could be more complicated, like a faulty sensor or clogged lines, requiring a dealership check-up. I make it a habit to check the fluid level monthly, especially before long trips, to avoid mid-journey surprises. Remember, never ignore it – repair bills can be hefty!
