Engine Management Light (Yellow Light On Dash)
If this light comes on it means the engine control unit (ECU) has detected a problem with the engine.
If the light is on and the engine is running smoothly you can drive the truck. However, it should be checked at the earliest convenience.
If the engine is running poorly the truck should not be driven.
The ECU will store the fault information that will allow the fault to be diagnosed when the ECU is connected to a PC.