There is no tuning box on it as far as I know,

Could it be possible that both sensors are faulty and not reading the correct values?

Stemh said:

There is no tuning box on it as far as I know,

Could it be possible that both sensors are faulty and not reading the correct values?

Click to expand...

Are you SURE that both sensors are connected to factory cables?


(that's a 500 but it's the same anyway)

21ish PSI that stem used to get on the pressure gauge (about 1,6 Bar) seems quite ok to me for a stock engine, isn't it ? Just checked my 1.3 mjt and max boost was 2,55 (@ MAP), which is 20ish PSI @ pressure gauge ; my MJT is free of any MOD !
BTW the electric signal from my MAP varies from 1,52 (atm press) to 4,09 volts @ full boost and it's a 3 Bar range... (unmodified).
I like the idea of installing a higher range MAP (on a Diesel engine) or even use a resistor divider to lower the signal to fool the ECU so it believes the boost pressure is lower than it really is and adjust the vanes accordingly, but I'm not sure the injected fuel would then be enough ... unless playing also with the Common Rail pressure sensor ??

Any thoughts about this Cmos ?

Regards, Bernie

Bernievarian said:

21ish PSI that stem used to get on the pressure gauge (about 1,6 Bar) seems quite ok to me for a stock engine, isn't it ? Just checked my 1.3 mjt and max boost was 2,55 (@ MAP), which is 20ish PSI @ pressure gauge ; my MJT is free of any MOD !
BTW the electric signal from my MAP varies from 1,52 (atm press) to 4,09 volts @ full boost and it's a 3 Bar range... (unmodified).
I like the idea of installing a higher range MAP (on a Diesel engine) or even use a resistor divider to lower the signal to fool the ECU so it believes the boost pressure is lower than it really is and adjust the vanes accordingly, but I'm not sure the injected fuel would then be enough ... unless playing also with the Common Rail pressure sensor ??

Any thoughts about this Cmos ?

Regards, Bernie

Click to expand...

Nooope. Don't do that. Stay away from that kind of stuff (resistors/boxes etc).

Custom map (tuning) is the only reliable way.

Out of curiosity, what's the pressure values on your sensors (atm,map,boost) with the engine off ? (key on)

cmosfxx said:

That's the abarth map correct.

Just to make sure, is there any Tuning box ecu installed?(tmc etc)

Click to expand...

Definitely no tuning box on it, all the sensor wiring goes straight back into the original loom.

I've found the old map sensor, going to try putting that back in, see if I get any different values. Worth a try! Haha

Here you go Cmos...

Regards, Bernie

Driving me mad this car!

Tried changing both sensors, still getting exactly the same readings. I haven't tried taking it for a drive yet to see if it drives any different.

But the boost pressure and intake pressure both still seem about 100mbar off the atmospheric pressure when engines off. Is there anything that needs to be reset or anything when these sensors are changed?

Stemh said:

Driving me mad this car!

Tried changing both sensors, still getting exactly the same readings. I haven't tried taking it for a drive yet to see if it drives any different.

But the boost pressure and intake pressure both still seem about 100mbar off the atmospheric pressure when engines off. Is there anything that needs to be reset or anything when these sensors are changed?

Click to expand...

All Sensors should have the same pressure with the engine off.
Where do you live? / altitude? (You can download barometer app for iPhone 6 and later models to read atm pressure, it's accurate)

Disconnect the battery for a minute.
This will restart the ecu.
Turn key to on without starting the engine like before and check again the values.

Also try to disconnect the no-name boost sensor and check again. (Don't start the engine)

According to iPhone barometer, air pressure is 1009 mbar. I've tried disconnecting both sensors, both reading go up to about 2100mbar when disconnected, then back down to 850 ish when plugged back in.

I've read about "self adapting parameters", do any of these affect the reading of the pressure sensors?

I've tried a couple of different sensors on the same connections and get exactly the same values. Is there anything else that can affect the readings with the engine off?

Thanks a lot!

Stemh said:

According to iPhone barometer, air pressure is 1009 mbar. I've tried disconnecting both sensors, both reading go up to about 2100mbar when disconnected, then back down to 850 ish when plugged back in.

I've read about "self adapting parameters", do any of these affect the reading of the pressure sensors?

I've tried a couple of different sensors on the same connections and get exactly the same values. Is there anything else that can affect the readings with the engine off?

Thanks a lot!

Click to expand...

1bar atm pressure.

So all the pressure values are wrong on your car.

Something is not right... I'm afraid there is a problem with the ecu.
Maybe the previous owner flashed a custom map or something ?

You can try to reset the self adapting parameters (disconnecting the battery resets these parameters too)

A new map in the ecu will explain the different readings.

Also something as simple as a ground will make the reading go higher.
Check all grounds with a multimeter set to read 2 volts:
-between all sensor ground and battery negative,
-between ECU metal case and battery negative.

There should be no voltage!!!
Also while you're at it, make sure the sensors get the live 5v signal.

Do not underestimate the importance of good clean power to sensitive things like ECU and sensors.


To me it seems that probably both MAP and Boost sensors are using a common ground or power wire. that will explain why they have similar readings.

Those sensors do not give me any confidence. get good quality Original Bosch ones.


Best way would be to find somebody with a t-jet /GP/500/bravo who will let you test his sensors and test your sensors on his car. ( test with MES)

I've just tried resetting self adaption parameters on MES. Didn't have change to have the car running at idle for 15 mins so will probably have to do it again. The only difference I have noticed looking at the figures is that the atmospheric pressure seems to have gone up to about 1020mbar. This sounds more like actual atmospheric pressure!

Could this be what's causing the fault code? The description is Barometric pressure out of range. Would 940mbar be considered out of range when atmospheric pressure is just over 1000?

Gonna be having another play tomorrow so will try some more of the suggestions!

Thanks a lot

Stemh said:

Could this be what's causing the fault code? The description is Barometric pressure out of range. Would 940mbar be considered out of range when atmospheric pressure is just over 1000?
Thanks a lot

Click to expand...

Not sure,. as i believe there should be some vacuum at idle ( in the pipe where that sensor is installed).
But with engine off the value does seem a bit off. so it might throw the error because of that.

If resetting the self adaptive parameters changed the value for the atmospheric pressure, it would suggest that the ECU believes that that sensor is reading to much; it has 2 other sensors that read much less. so it is trying to compensate for that - modifying the readings for atmospheric pressure.

Stemh said:

The only difference I have noticed looking at the figures is that the atmospheric pressure seems to have gone up to about 1020mbar. This sounds more like actual atmospheric pressure!

Could this be what's causing the fault code? The description is Barometric pressure out of range. Would 940mbar be considered out of range when atmospheric pressure is just over 1000?

Click to expand...

I said way back in post 14 that P2227 = Atmospheric Pressure Sensor.

Atmospheric pressure changes depending on weather conditions, and what altitude the car is at.

Davren said:

Fiat and several other manufacturers, P2227 = Atmospheric Pressure Sensor.

The Atmospheric Pressure sensor is located inside the engine management ECU and measures atmospheric pressure, not manifold pressure. It's subjected to different air pressure caused by weather conditions, or different altitude of the car, via slots in the side of the black bung on the ECU.
.

Click to expand...

cmosfxx asked you in post 36, and again in post 48:

cmosfxx said:

where do you live btw? what's the altitude there?

Click to expand...

cmosfxx said:

Where do you live? / altitude?

Click to expand...

It may be useful for people trying to help you, if you answered.
.

Stemh said:

According to iPhone barometer, air pressure is 1009 mbar.

Click to expand...

Sorry, I did miss it to start with, but I did what cmosfxx told me to do and downloaded barometer app on and posted the air pressure in my area a few posts ago. I'm from near Manchester, the cars been in the same location every time I've tried any suggestions on here.

Does the weather make a big enough difference to get the readings my car was showing?

Thanks

Hi Guys, just FYI ...

The "normal" extremes are about 3% of 1atm: 30"Hg (1atm) normal mini: 29"Hg, normal maxi: 31"Hg or 970 / 1030 mBar (all aproximatively !!)

Regards, Bernie

Ok. Let's start again from the beginning and try to clear some things out.

Original problem is P2227 error (MIL on) and low performance (low boost)

P2227 = Atmospheric Pressure Sensor.

------------------

Upon further research from Stemh we found that:

Atmospheric Pressure Sensor: 940mbar
MAP: 830mbar
Boost: 840mbar

These are the pressures with the engine off.
All of them should be the same. (same= atm pressure)

-------------------

Now we have 3 problems.

1. Atm sensor reading is LOW (it should be near 1000mbar since he is not living on mountains at very high altitudes)

2. MAP reading VERY LOW
3. Boost is reading VERY LOW

So both MAP and Boost sensors are -100mbar of Atm sensor. (940 vs ±840 - coincidence?)

------------------

Then he tried resetting self adaptive parameters (re-learn procedure)

Atm pressure is now 1020mbar (that's a normal value)

MAP and Boost are still ±840mbar (?)

Could this be what's causing the fault code? The description is Barometric pressure out of range. Would 940mbar be considered out of range when atmospheric pressure is just over 1000?

Click to expand...

940mbar is not considered an out of range value. The car is designed to work on such low pressures (high altitude)

What makes tha ECU thinks that this is an out of range value is that it reads TWO sensors with a lower pressure (map/boost= 840mbar) and ONE sensor with a much higher value (atm=940)

------------------

So what makes these two sensors reading wrong pressures?

I though that there must be a tuning box in there tricking the sensors, but there isn't such thing (as Stemh said)

aurick86 said:

Also while you're at it, make sure the sensors get the live 5v signal.

Do not underestimate the importance of good clean power to sensitive things like ECU and sensors.


To me it seems that probably both MAP and Boost sensors are using a common ground or power wire. that will explain why they have similar readings.

Those sensors do not give me any confidence. get good quality Original Bosch ones.


Best way would be to find somebody with a t-jet /GP/500/bravo who will let you test his sensors and test your sensors on his car. ( test with MES)

Click to expand...

Good thinking! Check voltage input and make sure it's 5v on both sensors.

------------------

What else you could try?

1. Remove the battery and check again.
2. Remove the boost sensor and check again (keep it disconnected - don't start the engine)
3. Remove the MAP sensor and check again (keep it disconnected - don't start the engine)

I have the same issue on an abarth 500, it only comes up if i switch of engine and start again after 5-10 mins. So when running small errants

When the error p2227 comes up i have no misfires on cold startup..... very strange