Air flow meter, faulty?

[Bod]

Trying to get rid of these codes in my 307 2.0 HDI (2004).

One of the ones on the Engine ECU is

Engine ECU : Permanent fault. Air flowmeter signal. Open circuit or short circuit to earth. Flow too low.

Clicking on the info I get

ECU Fault code : P0100
Engine Speed : 803rpm (I had it idling)
Air flow setting : 376 mg/impulse
Air temperature : 15 deg C
Intake air flow : 0 mg/impulse
Turbo pressure : 988 mbars





Now I unplugged it yesterday to see if it would make a difference.
Doesn't seem to drive much different at all. It feels like the quick acceleration (of the turbo?) kicks in later now (more near 1900 rpm instead of the previous 1500rpm or so).

I could be wrong though. Doesn't seem to be any discernable difference in performance.

Had a run out today and got the average MPG up to 33.4 (instead of the previous 32.8), although it was a longer run of higher gears so I dunno if that's anything to do with it.

Thoughts?

[jmkent]

Thats too small a change in mpg to hang you hat on

[Bod]

Hehe. Believe me, I've hung my hat on less

I'm surprised the car pretty much feels the same with it plugged in and without, surely somethings not right there?

[bettyswollocks]

If you unplug your airflow meter your car should be down in power if it is working

[Bod]

That's the thing, it's not, it drives pretty much the same (from what I can tell). If anything it seems smoother in power, and the extra vavawow that the turbo gives on a good toeing kicks in about 200 rpm or so later than usual.
This may be me just being clinical in thinking about it...It's probably driving exactly the same.

Now, should I be looking at the pipes for leaks etc, or just go for it and replaced the MAF?

[Gibbo]

The MAF went on my old 307 (51 2.0 HDI90) earlier this year. Unplugging made no difference whatsoever, but Planet diagnosed it as faulty.

Got a £30 one off Ebay and the fault went and the car was much smoother and better revving from cold.

[Bod]

A thread update.

I purchased a new MAF from eBay.

Fitted it fine, and cleared the fault codes.
Fired the engine up and retested with PP2000....Fault went away. Win.

That was just after boxing day.

Fired up PP2000 tonight, just to check, and the same fault code is there.
I cleared it and retested just incase, and it came back immediately as soon as I started the car.

I ran the parameters test while the car was running, what values should I be looking for? (Ive got screenshots so rather than type every single one out, I'll just post the relevant ones when I know which ones are relevant).

Driving the car seems pretty much the same. Getting about 36.7 MPG at the moment (I reset it since the first measurement in my first post).

[elmafudd]

That p0100 code has been bugging me for ages....ive a little info that might help tho....just follow the link.... i believe the p0101 is a very close match to p0100..... Code Descriptions