2000 V70 NA Intake Air Temp Sensor? Not used on 20 V engine

cannuck · Post by **cannuck** » 18 Dec 2018, 08:10

Lost my old registration somewhere, so I am here as a newbie.

One of our kids bought a 2000 V70 base slushbox many years ago as a low mile, one owner car. They moved on a few years ago to bigger and better things (third kid, so minivan time) but the brick was such a great and reliable car, we kept it as a spare/guest car/etc. It is now at 320,000 kms.

Last few weeks, it started flashing the ETS/M light, and then stayed on and went into limp home mode, so I pulled codes. Got a throttle position sensor code, and also an IAT intermittent over voltage code (generic OBDII P0113). When I go to my alldatadiy manual on line, it appears that the ECU uses the OUTSIDE air temp sensor to feed the fuel management. Is this right??????

Post by **abscate** » 18 Dec 2018, 08:55

On an NA I believe that is right. Remember the air box on an NA is warmed by exhaust riser, so it should be brought to a steady state in any temperature below the set point. I believe the air box admits unheated air anything above 50F from ancient bits of my RAM, considered 57% reliable.

A turbo with the vastly superior ME7 has an independent IAT sensor on the induction tube just before the ETB

Post by **oragex** » 18 Dec 2018, 08:58

As above, the intake air temperature is one of the engine parameters

Post by **Ozark Lee** » 18 Dec 2018, 08:59

That is basically true but I don't think it is the same sensor that the temp display on the instrument cluster uses. I know exactly where the sensor is on a turbo and I assume it is similarly placed on the N/A version. On the turbo it is on the pipe that feeds the ETM and it is one of two sensors. In the case of the turbo it is more or less just below the intake manifold but I think the ETM is on the end of the intake manifold on a N/A so the sensor is logically located on the pipe that goes from the MAF sensor to the ETM. The IAT and the MAP are plugged in side by side on the turbo version.

...Lee

Post by **misha** » 18 Dec 2018, 16:23

IAT(intake air temperature) sensor have nothing to do with ambient temperature sensor!
IAT sensor is NTC sensor just like ECT and uses intake air temperature to fine-tune the air-fuel mixture.
I assume that the car have 10v engine since non-turbo 20v cars don't have it....at least up to ME7.
It is placed on air filter hose where MAF is on 20v cars.

cannuck · Post by **cannuck** » 18 Dec 2018, 17:37

I think I am getting closer to the truth. When I called local dealer, they could not find IAT, so wonder if in official Volvoese it is called something different?

Post by **abscate** » 18 Dec 2018, 18:04

Isn’t temp compensation built into the MAF on 20 valve cars?

cannuck · Post by **cannuck** » 19 Dec 2018, 16:23

What has me baffled is the code. It is a generic OBDII code, P0113 (that is high IAT voltage input high but on my software read as intermittent IAT sensor high voltage). On the inlet pipework between the air cleaner and the throttle body, there are two devices: one is obviously the MAF and the other appears to be a solenoid valve onnected to the crank case PCV circuit (3 wire connection). I can see no place where there is an IAT sensor/sender.

So, one of two things: where is the IAT (if there is one at all). and what the heck is setting the code?

Post by **misha** » 19 Dec 2018, 17:25

Give us a picture of engine bay and air filter area.
N/a cars don't have IAT unless they are 10v.
What you used as a code reader?

cannuck · Post by **cannuck** » 19 Dec 2018, 21:39

it is a 20V engine (B5244S), 168HP NA.
Code reader is autoenginuity version 8 software
no where near car for pic right now.

BTW: thanks for the reply, explains why neither I nor the dealer parts kid could find a IAT sensor.