Breezy_Pete

Hang on a sec! I just looked up that fault code; and it relates to one of the exhaust temperature sensors, not the pressure sensor? Where did you get the idea it was the pressure sensor?

Can you get a photo?

You'll have to keep looking. Take some photos of the engine bay from high up, in good light and post them here. Someone may be able to spot it.

I'm not sure you have the correct location, which youtube video did you view? I'd think on your engine it would be somewhere at the back of the engine bay, high up. Find it and visually inspect it, as a first step. They have been known to melt.

If you have Freedom membership, you can post images freely without size limitations.

I doubt there's anything missing that should be there for your car, but here's your image anyway:

Oh, I see. What was the part number of the item replaced? (Should be on the bill) Is this a diesel or petrol engine?

Why was the coolant sensor replaced?

Find someone with a Fabia that also has the Koyo steering system and is willing to let you make some graphs of the voltages and current during the time when the PAS module is starting up in their car. Then you can see if that large current spike is normal or abnormal. All UK (RHD) mk1s have the TRW system, I think.

Forget about measuring resistances and concentrate on unbolting/cleaning/refitting the contact points of each end of each earth cable, especially the one between engine and chassis.

@VWD isn't 80 x 0.8 actually 64? But yeah, very high resistance, though likely to have been inaccurately measured.

How to undo VW wiring connectors. - YouTube

You (or a garage you trust) need to look from below, with engine undercover removed, I think.

Yes, but there are several VW specs. You use an oil which meets the one it states in the manual. Anything else is automatically guaranteed by the oil meeting that spec. If you create a login at erWin Skoda you can peruse the lists of oils that are compliant (and tested by VW group as being so) with each spec.

Which spec does the manual suggest?

Look to see if there is oil surrounding either connection at the compressor. If there is, photograph it, then clean it away, then check if it returns in a few days.

Your refrigerant leakage problem seems likely to be at one of the o-rings of the compressor connections. I guess they pinched (damaged) one of them when reconnecting to the compressor.

Mine's TRW.

Do you know if your car has the TRW steering system or the Koyo one? There may be differences in start-up behaviour.

As it says there, the PTFE is a coating for friction/wear reduction, not reinforcement. PTFE is very soft, you couldn't reinforce anything with it. The 'tension cables' are the reinforcement. Sorry if this seems pedantic, but it just sounds so wrong to my ears to hear 'PTFE reinforcement'.

I messed up this morning's logging, so here's a brief one I've done just now. This was just logging group 1 and 4, as the current logged in group 2 is the same as in group 1 I think, so no need to look at that too. Notable difference is that when the PAS starts up (with no steering wheel input yet), there is not the big current surge that is seen in your first plot, just a climb to the 'circulating fluid but not pumping hard' 3 amps standby situation. You can see on the right what happens when I give the steering wheel a bit of left/right waggling while stationary on block-paving. Maybe repeat your experiments to see if that big current spike happens every time the PAS starts up, even with no steering wheel movement.

I think the time difference in the sampling will partly explain the differences between the voltages. They can't be measured truly simultaneously. The other factor is the currents through the (non-shared) wiring will cause variable differences between the two voltages. I'm shortly going to do some logging on my car. See if you can make the PAS module start up reliably by not touching/moving the steering wheel during the first few seconds after engine start. See if you can make it go into error condition by deliberately moving the wheel during this time.

I think both voltage figures are as seen by the PAS module, possibly one is the terminal 30 permanent feed, the other the terminal 15 ignition-on feed from fuse 7. I will try to find more info tomorrow. Great data!

Quick and dirty parasitic current measurement - Handy Topics & Guides - BRISKODA

I've tried to describe this just in words far too often so it's about time I added some piccies and video. To measure the overall parasitic current correctly on modern cars, you need to use a bit of stealth. There are various reasons for this which I won't go into, but it entails setting things up so that you can have the car fully locked up, whilst still accessing the battery, and the car not getting awoken by any interruptions to the current supply. Start by opening the bonnet. Then push the bonnet latch down (like it would be if you let the bonnet drop again). Use a screwdriver or similar: Now the car won't think the bonnet is open even though it is. Loosen the battery negative terminal so that it can be pulled off vertically very easily, but then leave it fully down/connected: Now ensure all doors are closed, all keys are outside the cabin then lock the car, and leave it alone for at least 30 minutes. Set your meter up ready to make a measurement. Dial set to a range like 200mA DC and the probes in the appropriate holes: Now the bit that requires a little dexterity and care. Remember the important thing here is not to interrupt the current flow, or the many control units will all wake up from their sleep state, and the reading will be useless. Put the red meter probe onto the battery clamp and hold it firmly on there, with a grip that means you can also lift the clamp up with that hand; practice this if it isn't something you can easily do, or employ an assistant to add an extra hand. Put the black meter probe vertically downwards onto the battery negative post, through the battery clamp, so that the clamp can be lifted up around the probe, without touching it, or losing contact between probe and battery post. Lift the battery clamp clear and read the meter. Don't be surprised if the reading jumps about by a few milliamps (mA) this is likely to be the LED on the drivers door blinking to show the alarm is set. Video showing this process below : 20210704_161540.mp4 Note down the numbers, then do up the battery clamp again. Unlock and open the car, pull the bonnet release to re-open the latch, close the bonnet and you're all done. if the reading is significantly higher than a few (2 or 3) tens of mA, try again but leave a longer time between locking the car and taking the reading.