FACM reset

[CmaxNob]

Hi Tdci-Peter,

Thank you for all the information. I guess you right I missed those two wires.

I will follow up your suggestion and give a try without the pump disconnected to see if there are any changes in the errors.

My guts say you probably right there is a error in the facm.

I keep you posted.

Regards,

Norbert

[CmaxNob]

Unfortunately a facm is not available on the second hand market ..... I wonder why ...
Anyway, a short visit to the local Ford dealer learned me they are not really willing to help.
Only when you will give them a blanco cheque to solve the problem .....
Autel gives the indication that it can also a problem in the circuit, so I think I have to disconnect the additive pipe line ans see if I can blow it through.
If you have any other suggestions you have all my attention.Meanwhile my adapter of elm327 gives problems with elmconfig so I have to order a other (better) one.

[Tdci-Peter]

1 hour ago, CmaxNob said:

Meanwhile my adapter of elm327 gives problems with elmconfig so I have to order a other (better) one.

A source of ELMs recommended by many on this site is:

https://tunnelrat-electronics.fwscart.com/

Stick with USB if possible, it is often more reliable than wireless. The CAN & ELM protocols are not really compatible with wireless protocols. Too much inter-packet delay, I think, in wireless.

It is just possible that a dodgy ELM may be the problem with Forscan as well, being unable to write to the FACM, so definitely check that out. Dodgy ELMs are very, very common.

Ford dealers really hate the idea that car owners can do anything at all to their cars. That want that monopoly all to themselves, so they can charge whatever they want!

[CmaxNob]

I have received the new ELM but still I can't erase the error of DPF tank to low or empty.
To day I was able to order a second hand dpf tank an a second hand FACM module.
They will be delivered tomorrow afternoon  so Friday or the weekend I can try if one of those is the solution.
I will keep you informed.

[CmaxNob]

First I installed the new FACM after disconnected the battery. Then I connected the battery again.
Now I was able to use the option new FACM. In this option you have to check the fueltankflap in open and closed position.
Unfortunately the error of DPF tank to low or empty came up again so the FACM repacement was not the solution.
After that I replaced the DPF tank. I had to cut out the old tank and replaced it by the new (used) tank.
Filled up the new tank and the problem was gone! So the problem definitely had to do something with the DPF tank.
After this I did the stationary regeneration and everything is fine now. The consumption of the car is around the 4,8/100.
When I have time I will open  the old DPF tank to see if there is a sensor or something and how it is connected.
Thanks again for all the suggestions.

[gaz_moose]

Sorry to drag up an old thread  but do any of you guys know what the Vref wire actually does?

 

I have a constant P1922 fault within the FACM that wont clear. ive fitted a new FACM and can run a prime/ talk to the FACM but cant reset the P1922 code.

I did unplug the electrical connector from the EOLYs tank and the P1922 went away and I got a few codes that said it was unable to communicate with the pump.

I think I have a knackered thermistor inside the tank so im wondering if the Vref wire is the low level wire. Im wondering if there is a way to trick the level sensor? as that is the only thing keeping my car in fault, it knows the tank is actually full.

[Tdci-Peter]

7 hours ago, gaz_moose said:

I think I have a knackered thermistor inside the tank so im wondering if the Vref wire is the low level wire. Im wondering if there is a way to trick the level sensor? as that is the only thing keeping my car in fault, it knows the tank is actually full.

It is looking like some cars do have a real level sensor. My interpretation of the drawing is that there is a pot (3 wires) in the tank, presumably linked to a float arm. Vref, in all other cases I have seen, is just a constant 5v reference voltage. The clue would be if the signal wire is actually connected, via pin 3 on the tank (C987) and pin 13 on the FACM (C985).

I would not try to trick the FACM without some careful measurements. Shorting the signal line to Vref might do it, but shorting any two wires together without carefully finding out what they really do is dodgy!

[gaz_moose]

thanks for taking the time to reply.

 

i don't think it is a thermistor, the symbol on the diagram is that of a variable resistor.

my car only has the 3 wires going to the ELOYs tank. positive, negate, Vref.

 

unplugging the FACM removes the 'engine malfunction' warning from the dash but does flag up a U-error code and P2585 when scanned.

 

today I plugged the FACM back in then cut the yellow and green wire (11) to the FACM to see if no signal from the TANK would make a difference. I checked and had no voltage or continuity to ground on either side of the cut wire. it still flagged up P1922.

I then put a 12v feed onto pin 11 of the FACM to simulate a signal from Vref but it still showed P1922 when scanned. I did this by looping the y/g wire round into the back of the g/y (pin 3). not sure how to get 5V to it???

 

P1922 is a low level fault indicator, I know the level is actually full as I filled it up, I assume that its something inside the sealed tank that has failed causing the issue. I would be happy with just tricking the FACM into thinking the tank is full as that will clear the P1922 allowing the system to work again. It take minutes to refill the tank so I would just top it up every 20k miles.

 

the additive tanks seem difficult to get hold of for realistic money and seem a pain to change as by the looks of it you need to drop the rear axle.

 

knowing what voltage or resistance should be on the Vref wire would be nice.

Edited January 14, 2019 by gaz_moose
add more detail

[Tdci-Peter]

50 minutes ago, gaz_moose said:

my car only has the 3 wires going to the ELOYs tank. positive, negate, Vref.

 

unplugging the FACM removes the 'engine malfunction' warning from the dash but does flag up a U-error code and P2585 when scanned.

 

today I plugged the FACM back in then cut the yellow and green wire (11) to the FACM to see if no signal from the TANK would make a difference. I checked and had no voltage or continuity to ground on either side of the cut wire. it still flagged up P1922.

It does not look like there is any sort of real level sensor in there. If is was a variable resistor with a two wire connection (Vref & GNd), then you would either see some sort of energisation voltage from the FACM, or a resistance reading in the Tank.

I think it is back to software / electronics related problems.

1) Has there been a diesel re-fill after the Eolys fill, and FACM reset & prime operations? From a reply above, the FACM may not fully reset until a fuel fill that triggers a dose cycle.

2) If the replacement FACM came from, or was intended for, a car which DID use a real level sensor, then it will show an error if the Level Sens line is not connected to a sensor in the tank. It will have a different software configuration.

3) Following on from 1 above, if there is a problem with the filler cap sensing (magnet, sensor, wiring), then the FACM may be unable to be fully reset. Forscan or ELMConfig can, I think, monitor the operation of the filler cap sensor.

 

[gaz_moose]

 EEiveriive checked the fuel flap via elm config.

ive brimmed the diesel tank since topping up the eloys tank.

ive opened and closed the flap loads of times, even done the flap reset procedure.

ive reset the counters and primed the system on both of the FACM's I have using Forscan and Elmconfig.

Forscan has a 'reset FACM' feature but it wont let it run. it gets to about 10% then flags up an error code, even with the full licenced version.

I got the replacement off a slightly older version of the same car. the part numbers were the same as on mine.

the tank level sensor cant be a thermistor as previously mentioned because cars are tested to be able to work between -20 and +30 Celsius. so the fluid its-self cant really be relied on to cool a thermistor. 

 

my fault is P1922 which means it thinks the EOLYs level is low. I just need to some how tell or trick it to think that its not.

im thinking that I may have to bite the bullet and just buy a secondhand additive tank.

[Tdci-Peter]

On 1/15/2019 at 11:20 AM, gaz_moose said:

im thinking that I may have to bite the bullet and just buy a secondhand additive tank.

From what you are saying, and what I have just read, I am coming to the same conclusion, sadly!

An article on BBA-reman mentioned a piezo level sensor: http://www.bba-reman.com/forums/Topic135765.aspx

I then checked the Ford Workshop manual site, and it clearly showed it.

https://workshop-manuals.com/ford/focus_2004.75_07.2004/mechanical_repairs/3_powertrain/303_engine/303-04f_fuel_charging_and_controls_1.6l_duratorq-tdci_(dv)_diesel/description_and_operation/fuel_charging_and_controls_vehicles_with_diesel_particulate_filter_(dpf)/

A piezo sensor changes things a lot, there is no simple way with a meter to test or even detect it. It could have a simple two wire connection utilising the pins called  Gnd and (wrongly named in this case) Vref.

This contradicts almost all reports I have read, but both BBA-reman and the Workshop manual site are usually trustworthy.

 

[gaz_moose]

Quote

 

I actually looked at the manual and saw that but somehow it didn't register in my brain. DOH.. I was looking at it as when you look at the the tank it looks like you can just pry back the clips and slide that whole lot out.

 

I will try to pick up another tank. it looks like you have to lower the rear beam to get to the tanks mounting bolts which is a bit rubbish.

[Tdci-Peter]

5 hours ago, gaz_moose said:

I actually looked at the manual and saw that but somehow it didn't register in my brain. DOH.

Me too, DOH: When I opened the file I record details like this in, to add a note about Piezo Sensors, I found there was already one there! I must have seen this a year or so ago, noted it down, and completely forgotten about it. Kind of: Info saved to disk, Delete original in brain!

May be a sign of advancing years , advancing too fast!

If it is a sensor like that, then defeating it could be very difficult. Assuming the wire from D_Pump to +Pump is only live to activate the pump, then the sensor can only be a two wire (one plus Gnd) connection. It may be just an ultrasonic transducer (a piezo crystal that needs high frequency AC energising), or it may be a two wire electronic system like I seem to recall the Ford reversing sensors are.

Just because Ford only supply the whole unit does not necessarily prevent it being dismantled, if that would make it easier to remove. The 1.8TDCI EGR valve is like that, Ford say it must be replaced with the entire inlet manifold, but the actuator part is easy to remove, and is now available separately thanks to some enterprising Chinese manufacturer.

However you still need a replacement tank, and I had a quick look, but could not see any used ones for sale. I did not try very hard, it would be a bit surprising if they were not available.

 

 

[gaz_moose]

ive contacted a few people breaking them and they either don't get back to me or say its sold, so they either sell them or take one look at where they are located and decide the tank aint worth the effort.

by the looks of it I will have to drop the whole rear beam down to gain access to the torx head screws that hold the tank on. there is a self pick breakers yard not that far away from me so I will have to go and strip one off a breaker myself.

my MOT is due next month but I did find that just unplugging the FACM removes the big red warning triangle from the instrument display so I will probably just do that and swap the actual tank over when the weather gets better. I can just pour a few drops of the left over EOLYS fluid straight into the tank using the 'she wee'.

im sure I read that the 2L of fluid is good for 37000 odd miles and this thing does like 500 miles to a tank. it holds 2L of EOLYS so.. 37000/500=74 then 2/74=0.03L

[Tdci-Peter]

2 hours ago, gaz_moose said:

im sure I read that the 2L of fluid is good for 37000 odd miles and this thing does like 500 miles to a tank. it holds 2L of EOLYS so.. 37000/500=74 then 2/74=0.03L

The math sounds about right to me. I think I heard the tank was a bit under 2l, but it is better to overestimate, So thats 30ml for 40l of Diesel, or just under 1 part in 1000. Or 1ml per litre of fuel in simple terms.

It is a good idea to ensure that some of the Cerium Oxide (Eolys primary ingredient) is in the tank at all times. It does its job as the fuel is actually burned in the cylinder, not later in the DPF. So every stroke of the engine without Eolys can put unburnable soot into the DPF. The soot formed with Cerium Oxide in it will burn at a lower temperature than soot without it.

I believe that jlm PAT fluid is also Cerium based, and some 1.6 owners have used it for years.

The other problem is whether the ECU software will attempt regens if the FACM is disconnected. If it does, and Forscan should be able to tell you if it has, then there should be no limit, apart from your patience (!) of how long the manual additive method can be used for.

If your car was registered before 1 July 2008, then there is no MoT test on the MIL (or EML) light. Otherwise it must come on with the ignition, and then go out. That is all the MoT manual says about it. Also the DPF is inspected for visible "tampering", and the basic opacity (smoke) test is done. No mention of additive systems.

https://www.mot-testing.service.gov.uk/documents/manuals/class3457/Section-8-Nuisance.html#section_8.2

[gaz_moose]

my logic was that it would not use the additive system if it detected a fault.

ive just been driving it with the big warning light on the centre of the instrument cluster as it don't really bother me. I just figured I would unplug the FACM for the mot to save any bother. its kind of scary that you could buy a car with an empty/broken tank that just has the FACM unplugged, first thing you would know was when your DPF was knackered.

 

I must be getting old as I was putting it off till the weather gets warmer. I did top the tank up with JLM pat fluid which is why I have a small amount left. Im guessing that will be the decider when I fix it.. hahahaha.

 

I might see if I can use the 'tank prime' feature to empty the tank.

[tokamil100]

FYI

 

 

[jre]

@tokamil100, awesome images.  Did you by any chance measure the resistance across the piezo element?

There is an old Facebook page by Jomo Enginering sugesting that measuring an open circuit across the level pins, would indicate an empty tank, and if you know it full and still OC, then its likely broken:  https://www.facebook.com/johnnyjomo/posts/2580612665305335

 

[jre]

The following url would suggest that the piezo element is only used as an indication of "low" fluid levels, and not an actual measurement of how full/low the fluid is.

http://www.dieselmechanic.info/common-rail/bosch-common-rail-system-fuel-additive-pump-unit-2.html

Quote

The internal piezo sensor can only detect when the fuel additive tank is empty. In conjunction with the counter of the fuel additive control unit, this device thus provides additional certainty of detecting an empty fuel additive tank.

 

[a.tanas]

Hi!

The thread was very helpful and I just have repaired FACM tank after buying one (second-hand) and it was fitted in replacement of the original failed one. It failed after 250k km (150k miles) on Mazda 3 1.6 diesel, which you probably know is mostly Ford Focus in terms of engine systems.

I'd like to contribute with my measurement (with GM328 tester of Aliexpress) of the failed and the OK tank:

Measuring at the tank connector:

- the pump measures like a coil with resistance about 9 Ohm and inductance 5.1 mH.

- the piezo sensor, if failed, is open circuit while tank empty.

- the piezo sensor, if OK and tank empty, measures capacitance 975 pF.

 

Measuring at the FACM cable loom connector:

- the piezo sensor, if OK and additive filled, measures resistance about 20 MOhm.

- the piezo sensor, if failed and additive filled, measures resistance about 150 pF (effectively this is cable loom's capacitance).

 

One useful observation: While you have the MIL light On at the dashboard, the system still tries to add whatever available in the tank. It's worth to continue driving with the FACM installed on the car to avoid quick clogging of the DPF. I soldered a 12 V buzzer in parallel to the pump pins inside the FACM black box. This way when 12 V are being fed to the the pump the buzzer rings.

After filling fuel at the petrol station I departed and after 2 mins of driving I heard as series of pulses (much like a ringing phone for 2-3 secs) which is equal to some 50-100 pulses to the coil, ejecting droplets to the tank.

 

[Tdci-Peter]

On 12/7/2020 at 9:17 PM, jre said:

Did you by any chance measure the resistance across the piezo element?

A piezo element, unless badly damaged or contaminated, should always read very high resistance (more then 10Mohms) on a resistance meter. It will be the capacitance that changes if anything. So you would need a meter capable of reading capacitances in the range of say 10pF to a few 1000pF to test it, as Atanas had.

The fact that it seems to be a simple on/off low level sensor makes a lot of sense. When you energise a piezo crystal with ac, it vibrates. This has a big effect on its measured capacitance. Immersing it in fluid damps down the vibrations, with a quite simple to measure change in capacitance. The old theory that it was all down to counting the pump pulses and estimating fuel tank fill level remains largely correct, just there is a alarm alert at low level from the capacitance sensor.

It is a pity all this information was not made freely available by Ford years ago, it would have benefited a lot of people! And probably saved a few cars from a premature visit to the scrap man! A simple on/off sensor like that would be easy to replicate, and get working without the astronomical and uneconomic cost of a complete tank ./ pump / sensor system.

 

[Johnale0966]

Hi guys I have very similar issue to this I have system engine fault and comes up with these two codes p1922 fuel additive level Circuit and P1922-60 fuel additive level circuit the garage refilled the tank via the wrong pipe filled it through the overflow pipe and not the fill so could this be why I’m not getting rid of the codes and if you turn it on and off then back on very quickly while engine is running nothing shows up but if you turn it of leave a min and turn back on it comes straight back on any advice would be truely appreciated thanks guys 

[Pablozz]

On 1/2/2021 at 1:17 AM, Tdci-Peter said:

A piezo element, unless badly damaged or contaminated, should always read very high resistance (more then 10Mohms) on a resistance meter. It will be the capacitance that changes if anything. So you would need a meter capable of reading capacitances in the range of say 10pF to a few 1000pF to test it, as Atanas had.

The fact that it seems to be a simple on/off low level sensor makes a lot of sense. When you energise a piezo crystal with ac, it vibrates. This has a big effect on its measured capacitance. Immersing it in fluid damps down the vibrations, with a quite simple to measure change in capacitance. The old theory that it was all down to counting the pump pulses and estimating fuel tank fill level remains largely correct, just there is a alarm alert at low level from the capacitance sensor.

It is a pity all this information was not made freely available by Ford years ago, it would have benefited a lot of people! And probably saved a few cars from a premature visit to the scrap man! A simple on/off sensor like that would be easy to replicate, and get working without the astronomical and uneconomic cost of a complete tank ./ pump / sensor system.

 

Hi everyone!

Is there any solution for broken piezo sensor in FAT? How to cheat FACM that piezo sensor sees always full tank?

BR,

Pablo

PS. Sorry for my english, guys;)

[Tdci-Peter]

1 hour ago, Pablozz said:

s there any solution for broken piezo sensor in FAT? How to cheat FACM that piezo sensor sees always full tank?

I can not see any easy, quick solution, I am afraid.

As the crystal energising and sensing happens in the FACM, with the output from a processor digitally on to the CAN bus, there is no obvious wire or pcb track that can be cut, and just connect in a switch.

If I was asked to design something like this, at minimum cost of parts, I would use a processor chip with a spare crystal oscillator input on it, so that the oscillator started up when the sensor was dry, and either changed frequency a lot, or more likely stopped oscillating altogether when under the fluid. If that is what has been done, then a crystal that works at the right frequency will be needed. Starting and stopping the oscillation would then be easy, just connect a suitable resistor across the crystal, or short it out, or disconnect it.

Alternatively it could be just a capacitance sensor, in which case two capacitors, one to simulate dry & one to simulate under the fluid, would do.

But finding what is actually needed to fool this circuit into seeing full tank would require some quite serious investigation. I have not heard of anyone doing it.

 

[Vadim G]

So I got error P1922-60 and with it P2585-61. I tried to connect another tank to the connector, but the errors appeared again. True, I cannot guarantee the serviceability of the donor barrel. What do you think? Where to look for a breakdown?