U2521 Volvo Duett DTC Code

Volvo Duett Engine Specifications:

Engine Type :	Multi-Cylinder Engine
Cylinder Type :	V-Type Engine
Engine Air Intake Process :	Supercharged Engine

Your Volvo Duett engine control system detects a problem, the computer stores the diagnostic trouble code U2521 in its memory. To figure out what is wrong with your vehicle you must first extract the U2521 DTC For Volvo Duett.

Another consequence of U2521 Volvo Duett engine overheating may be a blown head gasket. Heat makes aluminum swell almost three times faster than cast iron. Thermal stress can distort the head and make it swell in areas that are hottest like those between exhaust valves in adjoining cylinders, and areas that have restricted coolant flow like the narrow area that separates the cylinders. The typical aluminum head swells most in the middle, which can crush the head gasket if the head gets too hot. This will usually cause the head gasket to leak compression between adjacent cylinders, or leak coolant into the cylinders.

U2521 Volvo Duett DTC Meaning

U	Network Code - Problem is climate control system, lighting, airbags, etc.
2	MFG - Manufacturer Specific
5	Auxiliary Emission Controls
2	Cruise Control Servo Indicates Low
1	PCM Stack Overrun

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. U2521 Volvo Duett code had an elaborate diagnostics procedure, including showing engine trouble codes on the air conditionning display. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired.