Breezy_Pete

It could easily remain running after engine off for a short while (mediated by radiator thermoswitch being above its lower threshold temp), but I doubt it can start up after ignition off. Not sure if I have wiring info for your car. You are worrying unnecessarily.

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. 👍

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.

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

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.

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.

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.

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.

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.

It looks like you have a black/blue wire coming from pin 1 (L) at the alternator, becoming blue at either a 2-pin or 4-pin connector pair (with/without A/C fitted) and finishing at pin 4 of a black 8-way connector of the onboard power supply control unit in cabin. Then there's a black/brown/red tri-colour cable from pin 2 (DFM) of alternator connector, becoming blue/white at the 2 or 4 pin connector and going to pin 64 of the 94-way engine ECU connector (on a different page, box 93 tells you where to go).

BLS is enough. I will research the wiring info soon.

Unplug the 2-way connector from the alternator and measure the voltage on each wire with ignition switched on. That should quickly establish if either is broken.

Have you checked the DFM wire all the way back to the engine ECU? If not, tell me your engine code if you want info on where to look.

Not on the list of Castrol oils approved to 507 00 , no. Document current at 13.03.2023

Good point. How? A blowtorch may be the way to go, carefully.

So you need to start a new thread in the general mk1 Fabia subforum Skoda Fabia Mk I (1999-2007) - BRISKODA, this thread is just about wiper relay replacement.

Wow, super-low. Not always a good thing.

Not sure, but certainly not MAF, your engine doesn't have one. It uses manifold pressure (MAP) sensor for air measurement. How many miles has the car covered?

Red/blue wire on pin 1 of the connector should have 12V from fuse 31 (10 amp) any time the engine is running. Brown wire from pin 2 goes to engine ECU pin 4 on the 81-pin connector.

That is bank 1 sensor 1. 👍 You only have 1 bank of cylinders and sensor 2 will be further from the engine. The heater may be a positive temperature coefficient (PTC) type, and if so its resistance will vary strongly according to the temperature it is when measured. So it may well be OK. If you can tell me your engine code (or VIN) I can look up the wiring information. One side of the heater is usually directly from a fuse, the other side to an engine ECU pin.

Yep, pretty sure that's correct. Not sure on compressions, maybe a bit on the low side especially on 2 & 3. Maybe worth repeating and trying in different conditions, cold engine and warmed up, to see if that reveals anything?

Have you got a compression tester? Can you have a look under the car and check what bar rating is stamped on the end of the fuel filter? (Just in front of rear right wheel)

DQ200 on this car.

Possibly a relay failure: Wiper relay replacement - Skoda Fabia Guides - BRISKODA

Ah, OK, I missed that the sensor was replaced.