What does the DEF indicator on the JMC Transit instrument panel mean?
2 Answers
JMC fault light DEF refers to the indicator light of the car's auxiliary water tank, indicating that the auxiliary water tank is short of water. The auxiliary water tank needs to be filled with water immediately to eliminate the fault. The following are related introductions: 1. Auxiliary water tank shortage: It needs to be added immediately. If it is a problem with the internal instrument processor, it needs to be dealt with immediately at the 4S store in the area. The car dashboard is a device that reflects the working conditions of various systems of the vehicle. 2. Function: The main function of the car auxiliary water tank is that when the car engine temperature is high, the liquid expands, and part of the antifreeze flows into the auxiliary water tank through the water tank cap; when the temperature drops and the cooling system pressure is negative, the system sucks the antifreeze in the auxiliary water tank into the cooling system through the water tank cap. At the same time, the auxiliary water tank is marked with corresponding scales to indicate the level of the liquid.
When I used to drive the JMC Transit, I encountered a DEF warning. After checking, I found it indicated an issue with the diesel exhaust fluid. DEF is that urea solution used to reduce emissions. If the fluid level is low or there's a system malfunction, the vehicle might limit speed or even fail to start. That time when the light came on while I was on the highway, I quickly found a service station to top up the DEF, which solved the problem. But it's important to note that DEF has a short shelf life, so buy genuine products and store them properly to avoid impurities clogging the system. In this JMC model, the DEF tank is located near the rear wheels, making it easy to operate—just be careful not to spill it on your hands. Regularly checking the fluid level can prevent issues. I recommend carrying a spare bottle of DEF with you, as shortages are more common in winter.
