How to replace mass flow sensor Volvo V 70 DIY
19A mass (air) flow sensor (MAF) is used to find out the mass flowrate of air entering a fuel-injected internal combustion engine.
The air mass information is necessary for the engine control unit (ECU) to balance and deliver the correct fuel mass to the engine. Air changes its density as it expands and contracts with temperature and pressure. In automotive applications, air density varies with the ambient temperature, altitude and the use of forced induction, which means that mass flow sensors are more appropriate than volumetric flow sensors for determining the quantity of intake air in each cylinder. (See stoichiometry and ideal gas law.)
There are two common types of mass airflow sensors in use on automotive engines. These are the vane meter and the hot wire. Neither design employs technology that measures air mass directly. However, with additional sensors and inputs, an engine's ECU can determine the mass flowrate of intake air.
Both approaches are used almost exclusively on electronic fuel injection (EFI) engines. Both sensor designs output a 0.0–5.0 volt or a pulse-width modulation (PWM) signal that is proportional to the air mass flow rate, and both sensors have an intake air temperature (IAT) sensor incorporated into their housings for most post OBDII vehicles. Vehicles prior to 1996 could have MAF without an IAT. An example is 1994 Infiniti Q45.
When a MAF sensor is used in conjunction with an oxygen sensor, the engine's air/fuel ratio can be controlled very accurately. The MAF sensor provides the open-loop controller predicted air flow information (the measured air flow) to the ECU, and the oxygen sensor provides closed-loop feedback in order to make minor corrections to the predicted air mass. Also see MAP sensor.
The Volvo V70 is an executive car manufactured and marketed by Volvo Cars from 1996 to 2016 across three generations. The name V70 combines the letter V, standing for versatility, and 70, denoting relative platform size[2] (i.e., a V70 is a larger car than a V40, but smaller than a V90).
The first generation (1996–2000) debuted in November 1996[3][4] as the estate variant of the Volvo S70. Both cars were essentially redesigned Volvo 850s which had itself been available in saloon and estate configurations. The V70 was available as a front and all-wheel drive estate, the latter marketed as the V70 AWD. In 1997, a special AWD version called V70 Cross Country, badged as V70 XC, was presented and went on sale for model year 1998.
The second generation (2000–2007) shared styling by Peter Horbury[5] as well as major mechanical commonality with the Volvo S60 saloon and was based on the P2 platform. With a 4 cm increase in width and height, a 5 cm longer wheelbase, a slightly shorter overall length than its predecessor,[6] and a slightly increased interior cargo volume it went on sale in early 2000.[7] As with its predecessor, the second generation was also offered as an all-wheel drive variant which was marketed as the V70 AWD and as a special version called V70 XC, which for model year 2003 was renamed to XC70 .
The third generation (2007–2016) was based on the Volvo P3 platform, sharing general styling and much of the interior in front of the b-pillar with the second generation Volvo S80. It has been marketed since 2007 as the V70 and the XC70, a crossover model.
Production of the V70 ended on the 25th of April 2016, the XC70 continued until May 2016.