[Engine] 2010 1.6 HDI consul display fault

[brian smith]

Have an issue 1st Code P0104 =Mass or volume air flow circuit intermittent.
Also on consul display anti pollution, plus orange fault on main display.
I have replaced mass air flow part. Also tried running at high revs to clear or burn out, but no smoke or muck coming out.
does this model have a dpi filter in the exhaust system ?
Thanks & hoping

[Sol]

It is very likely you have a DPF but there are threads on here about how to tell.

Running at high revs is not guaranteed to start a DPF cleaning cycle as certain conditions have to be met, for fuel tank level, speed, engine rpm and filter soot levels before a burn will be initiated by the ECU.

Citroen definition:
P0104 Flowmeter signal : Open circuit ; Short-circuit to positive ; Short circuit to earth

So you could have a wiring fault at the harness to the flowmeter as this fault code relates to no flowmeter signal received.

Other airflow errors relating to the measured quantity are often due to the EGR being dirty or sticking but this code is a signal fault so there is probably still an issue with the wiring between the sensor and the engine ECU.

Anti-pollution warnings can be generated from a multitude of areas and any fault relating to airflow measurement or EGR flow, exhaust pressure, DPF differential pressure can all put the anti-pollution warning on with associated codes. In your case I would check the plug pins to the AFM, the wiring for chafing or damage all the way back as far as you can see from the AFM and also check all engine bay fuses as there could simply be a loss of 12v to the sensor power pin.

Check with a meter or 12v test lamp, from a good earth (like the body earth strap to the right of the battery / fusebox on the inner wing) to the pins on the AFM (should be 3 or 4 pins) and one of them should be at 12v with the ignition on. If none show 12v then you have a blown fuse somewhere (check F1,5,10 & 13 especially):

Engine compartment
Citroen C4 Picasso I (2007) / Berlingo B9

Assignment of the fuses in the Engine compartment
Reference Rating Functions
F1 20A Engine management
F2 15A Horn
F3 10A Screen wash pump
F4 20A Headlamp wash pump
F5 15A Engine components
F6 10A Xenon dual-function directional headlamps, headlamp height correction motor, clutch switch, BCP (protection switch box)
F7 10A Automatic gearbox, engine coolant level switch, power steering
F8 25A Starter motor
F9 10A Stoplamp switch
F10 30A Engine components
F11 40A Rear blower
F12 30A Screen wipe
F13 40A BSI (Built-in Systems Interface)
F14 30A Air pump, heat exchange saver
F15 10A Right-hand main beam
F16 10A Left-hand main beam
F17 15A Left-hand dipped beam
F18 15A Right-hand dipped beam