2010 fabia 1.2 HTP. cranks but wont start, runs briefly (seconds) with easy start. new ecu coded to vehicle including immo . no fault codes showing on OBD scanner. not immo problem as immo lamp would remain on and an immo related fault code present. 

 

suspect fuelling problems as cant hear fuel pump running and no volts present on the two thick wires on the fuel pump connector  on the fuel pump access panel under the back seat. thick wires are brown (pin 5) and blue/white (pin 1), presume these are for the fuel pump not the sender. ? 

checked relevant fuses. 

relays not in end of dash position as relay info (online) suggests they are/ should be , but under the dash above the fuses. could someone pls confirm fuel pump relay position, and part number for new one would be helpful. happy to try a pin compatible cheap/ generic one if I can find out which one it is and pin configuration.  

 

it has also been suggested to check the main engine control relay, wherever that is ? 

wiring diag would be good also, if available. 

 

many thanks all !

Please supply engine code or VIN.

There are two different Mk2 Fabia 1.2 HTP engines, 6-valve 60PS and 12-valve 70PS; need to know which for wiring info to be useful.

thanks for your reply, there is a code on the ECU label I noticed, CPGA (should be CGPA ?)  I don't know if that's the code or if it makes sense, will confirm.  I was aware (have read somewhere) these are available in 2 or 4 valves per cyl but, TBH, I don't know which one this one is. 

However, and rather confusingly, when I search veh details on the reg it comes up with 60 hp/ 44 kW/ CHFA  / 6V (valve?) 

so looks like could be 6 valve / 60 hp.

What's the part number on the ECU (photo?)

Is it identical to the original ECU?

I wouldn't expect an ECU for a CGPA engine to be interchangeable with one for a CHFA.

 

 

03D906023M is the PN on the new one, not sure what the old one was as don't have this any more but, yes, I had same thought as you ! I can post a pic of the label if that helps. 

Please supply vehicle VIN, in private message if preferred. That may help; as 03D906023M doesn't appear as a current part number for 2010 Fabia in the parts programme I'm looking at. At least with VIN we can confirm engine code and probably the ECU part number it was built with, and any superseding part numbers.

 

Can you retrieve the old ECU? They are usually extremely reliable so it probably wasn't at fault.

 

Edited 16 September, 20232 yr by Breezy_Pete

ok yes will do and PM you - standby ! may be able to get the old one back. appreciate the advice.  🙂

If you've fitted the wrong ECU then I'm not surprised it won't start!

 

Like @Breezy_Pete says, it's almost NEVER the ECU at fault so refitting the old one should get it running again.

Ok point taken, but it wasn't running with the old one either. Replacement ECU was supplied by a specialist, so should be the correct part. May have two / multiple faults, fuelling being one, hence keen to bottom that one out. Can try and get the old ECU back though and try this again, meanwhile if you can advise what else might be at fault / should be checked / changed, e.g. with the fuelling circuit, or other system, to get it running again, that would be great !

The first place I would start with a 6V is with a compression test, you can do this even though it won't run.

12 minutes ago, abba said:

Replacement ECU was supplied by a specialist, so should be the correct part

Could be an OK part judging by this page: Control unit for petrol engine Skoda Fabia 5J 03D906023M | oemVWshop.com

In the description area it lists the right (44kW) engine.  If that's what you actually have!  The CPGA written on it is just coincidentally similar to an engine code, I think, and misleading us.

Edited 16 September, 20232 yr by Breezy_Pete

Hi yes I didnt mention at the time, but I also searched on the ECU part number and ecu.de listed it as being for the 44 kW CHFA, so the CPGA ref could be coincidental, as you say, as there is no engine code of this type, only CGPA (for the 1.2 vw engine, at any rate).  If so, sorry about that red herring  !

https://ecu.eu/skoda/engine-control-unit/simos9.1/skoda-03d906023m-continental-5wp40911-119320.html

Skoda Fabia 1.2 (Fabia, 5J) Year of manufacture 2008 - 2011 Engine code BBM, CHFA

 

Also this one which looks identical  (and also says CPGA) 

https://www.cartechelectronics.com/plug-play-continental-engine-ecu-vw-ag-03d906023m-03d-906-023-m-5wp4091105-5wp40911-05-simos-9-1/

 

still to confirm exact vehicle details I'm afraid...

meanwhile ref fuelling, is there just the one pump in the fuel tank  - usually there is a high pressure pump as well ? is there a port where we can check fuel pressure in the common rail which supplies the injectors ? also somewhere we can check fuel is getting up from the tank ok to the high pressure pump, if we have one,  and wherever that is ?! 

 

I dont have a workshop manual yet, I see Haynes do one that might help (ref 6033), though it wont have full wiring diags, not sure where I get those.  a manual might answer some of my newbie questions, as I'm not familiar with this vehicle yet. 

thanks again. 

interesting, this post (scroll to end) suggests should be able to hear fuel pump priming when the driver's door is opened ... ? pretty sure that's not the case, if true. !

 

 

The VIN is visible at the base of the windscreen, from the outside. 

I'm not going to spend my time finding wiring info until I have a positive identification of the engine type, and build date of car, which I can definitively get from the VIN.

ok understood, i dont have access to the veh at the moment, but will advise asap. 

11 hours ago, abba said:

2010 fabia 1.2 HTP. cranks but wont start, runs briefly (seconds) with easy start. new ecu coded to vehicle including immo . no fault codes showing on OBD scanner. not immo problem as immo lamp would remain on and an immo related fault code present. 

On the contrary it sounds exactly lik ean immobiliser problem which is pretty much what I would expect after an unnecessary ECU swap.

 

1.2HTP is a petrol engine am I right? Then you have ignition for a couple of seconds before it cuts out which is precisely what the immobiliser does, you did the right thing testing with easystart but you drew the wrong conclusion, you may have had and may still have a fuel pump problem proven by it starting on Easystart but it cutting out after 2 seconds is 100% the immobiliser in my not so humble opinion, if you refit the original and no doubt faultless ECU it will probably run for as long as you drown it with easystart exactly as a diesel engine would do except on that the immobiliser would not hamper it.

 

Best to limit the easystart, engines become addicted to it! And that is serious and not a joke.

I totally agree JR sounds like immo problem, but Im assured by the ECU supplier this has been done (i.e. immo coded to ECU).  but certainly not ruled out as a possibility just yet. Yes 1.2 HTP (petrol), as per title of topic. Point noted re easy start.

btw what circuit(s) does the immo interrupt, is it just the fuel pump / injectors etc ?   seems to be what you're suggesting is the case. e.g. hard wiring fuel pump would bypass the immo ? 

All opinions and suggestions, humble and not so humble, appreciated - keep 'em coming !

I'm not sure that an ECU supplier can code an ECU to the immobiliser unless you sent the instrument cluster to them and even then perhaps the keys would need re-registering, maybe not so on the latter part.

 

I bought a "plug n play" remapped ECU, it basically was programmed to ignore any input from the immobiliser and start from any key that would turn the ignition barrel so no more security, I did this because I did not want to send away my old ECU and perhaps instrument console and risk not getting them back or having the problems that you have, looks like it was a shrewd choice.

 

I sincerely hope you have retained your old ECU, in which case put it back on pronto to prove/disprove that the issue is within the new one, if not I would not spend any time trying to overcome the immobiliser, I would get a dealer level software like VCDS and it should tell you exactly what is not working and why, my gut feel is that the key is not recognised and the immobiliser is activated.

 

A generic OBDII reader will not interrogate individual modules and only display safety and emissions related generic OBDII fault codes, not immobiliser data

The RFID chip in the key is read by the instrument cluster using an inductive loop antenna around the ignition lock, these can give trouble due to dry joints in the instrument cluster where it plugs in.

thanks for your replies and comments, however, the vehicle didnt run at all before with the old ECU and easy start whereas it does now, hence the conclusion that we (still) have a fuelling problem, and the reason I raised this topic.  we havent seen (or maybe got ?) an immobiliser warning light on the dash either, so dont think this is the issue. I will hook up to diagnostics, e.g. VCDS, just we havent had a chance to do this yet. the cluster seems to be working ok also.  

As noted above, I'm hoping someone can help out with relays etc as the info available online does not match the vehicle, for some obscure reason, also wiring info would be helpful, or pointer towards where this info can be obtained. many thanks. 

Check that you have a 10 amp fuse in position 29 and that it is intact. (Injector power)

will do, in addition to #29, info I have found online ( as fuse cover with annotation has gone AWOL) says, for fuel-related fuses, 

#20 fuel pump relay etc 15A

#29 Injection etc 10A (as above)

#30 Fuel pump etc 20A

#32 High pressure pump etc 15A (assume this fuel ?)

confusingly, there are often multiple current ratings given for a each fuse, I have taken the highest in the above, rightly or wrongly.

Also check Fuse 16, 5 amp (fuel pump relay coil feed) .

Fuel pump relay is in position 7 of the relay panel, ECU relay in position 13.

Not easy to say what others there should be on your car.

 

Fuse allocations and values vary with options and engine types, as do relays.

Your car does not appear to have the 'open driver's door, fuel pump spins up' feature.

 

Sorry to drip feed, but I'm tired and the engine-specific wiring alone for your car runs to 15 pages, and you have to dodge back and forth between pages to trace some connections.

CHFA engine, car built 02/08/2010. 👍

1 hour ago, abba said:

thanks for your replies and comments, however, the vehicle didnt run at all before with the old ECU and easy start whereas it does now, hence the conclusion that we (still) have a fuelling problem, and the reason I raised this topic.  we havent seen (or maybe got ?) an immobiliser warning light on the dash either, so dont think this is the issue. I will hook up to diagnostics, e.g. VCDS, just we havent had a chance to do this yet. the cluster seems to be working ok also.  

As noted above, I'm hoping someone can help out with relays etc as the info available online does not match the vehicle, for some obscure reason, also wiring info would be helpful, or pointer towards where this info can be obtained. many thanks. 

 

I have to say that unless the car has been struck by lightning the chances of an ECU or fuel system failure are vanishingly small.

 

Which is why I flagged up the FAR more common RFID antenna fault.

Edited 17 September, 20232 yr by sepulchrave