P0100 diagnostic fault

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Diesel engine related problems
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My Name: Efftek

Posts: 1
Joined: Wed Aug 15, 2018 8:04 pm
Model: C3 2013-2017 Facelift A51
Year: 2016 (16)
Engine Size: 1.6 (16v)
Fuel Type: Diesel
Mileage: 80000
Trim Level: VTR+
Gearbox: Manual 5 speed


Guys, I have a 1.6 Hdi 120 diesel. It was a 16 plate (now has Cyprus plates as I brought it over with me from UK last year) A few weeks ago, I got an engine fault warning. It turned out to be a P0100 code so I looked it up and its Mass Airflow Sensor. I bought cleaner and cleaned the sensor, reset the code and went for a run. After a minute or so, the fault came back on. I cleaned it again to be sure and the same. So I ordered a replacement sensor - pre used but guarenteed working. The same thing happened - it went for a couple of minutes but as soon as I started accelerating away from the end of our road, the fault came back on.

I have reset it a few times. I can drive a while as long as I dont accelerate hard. It seems to come on at about 2200 rpm. Now I can hear a whining noise when Im accelerating up hill etc. As soon as I ease off, it goes away. The noise doesnt happen no matter how fast I rev with the car stationary so I cant tell where its coming from.

Any ideas?

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My Name: Arfur Dent

Posts: 3520
Joined: Sat Jul 23, 2011 3:47 pm
Model: C3 2002-2005, Original shape model
Year: 2002 (52)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 100000
Trim Level: Exclusive
Gearbox: Manual 5 speed
Engine name: DV4 16-valve diesel (90 PS)
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Hi Steve

The test for MAF is to disconnect it and test drive to see if it drives better or worse. Only after that you should decide to replace it or not.

MAF faults are flagged even if the MAF is not faulty (which is how codes work and is correct functioning of the ECU).

How did the car run and drive with the fault?

How does it run and drive with the MAF disconnected?
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