someone with a T5R

[Cypher007]

i think that picture shows the outside air pressure sensor, ive got one like that further up next to the horns and stuff, could be wrong though. also the climate sensor is normally mounted above the pollen filter, but my ones no where to be seen, the sensors your refering to, TheG, are the inside climate control sensors.

[TheG]

why on earth would it need an external air pressure sensor? AFAIK there is no external temp sensor for the climate control as such, it might use the same one as the trip computer? Dunno, I was just listing other sensors incase it was of any use

[Cypher007]

theres an external air pressure sensor which feeds the ECU with information as to the altitude your driving at, and then adjusts the turbo charge pressure i think.

[TheG]

I would have thought that any air based information like that would come from the MAF?

[Cypher007]

Air Temperature Sensor
Information gathered from air temperature sensor is combined
with information from pressure sensor to calculate intake air mass.

http://www.volvoclub.org.uk/tech/ser...ryOpertion.pdf

[TheG]

Intake air mass is taken from the MAF so I wonder if they're calling the MAF the "pressure sensor"?

edit: just read that and they're not. Odd, never heard of the pressure sensor before.

[Cypher007]

the MAF sensor just reads the air flow, which varies in mass depending on the outside air pressure and temperature e.g. cold air=greater mass of oxygen and lower air pressure=lower oxygen. so by taking the temperature, pressure, and air flow readings the ECU can work out how much air is entering the engine.

is this about correct? someone stop me if im dribbling.

[bb54]

Originally Posted by Cypher007

the MAF sensor just reads the air flow, which varies in mass depending on the outside air pressure and temperature e.g. cold air=greater mass of oxygen and lower air pressure=lower oxygen. so by taking the temperature, pressure, and air flow readings the ECU can work out how much air is entering the engine.

is this about correct? someone stop me if im dribbling.

hi,
cold air= dense air
warm air = not so dense
high air pressure(sea level) = oxygen rich
low air pressure (altitude) =oxygen lean

im wondering if the artical is being misread...

im thinking (could be way off) that the pressure sensor that has been mentioned could be refering to a charge air pressure switch, on the inlet manifold or intercooler to inlet manifold pipework ???
im not sure if one exists tho.

also,would the oxygen content of the air not be worked out by the lambda sensor reading the amount of oxygen left in the exhaust gases ?

wayne

[Cypher007]

disconected the sensor Miss Dmeanor photo'ed and it is the outside air temp sensor, doh!!! so now i just need to find the climate control outside air temp sensor.

[bb54]

doh !!!
i meant the charge air pressure sensor, not switch.
ive had a hard day watching tv he he.

wayne