Random PAS, no battery light, no charge voltage until revved 1.5-2k, + codes

May 24, 2024
1
0
Hi All, quite a long initial post, I've stepsons car here for some help, not a car I work on, so am quite unfamiliar with them, Minis, fine:)

This is a 6J CAYC CR 1.6TDi Sport

Issues are essentially random PAS, it went off on him, but does still work at random, either light feel, heavier feel, or off

Warning light can be on or off with any scenario, also at random

I don't have VCDS, but do have Autel Elite and Elite 2 Pro, either have pretty much the same info

The only common, and pretty much permanent fault stored is this:
IMG_5153.JPG


Note the battery voltage in the top right corner, at this time it was as the car arrived and reflects a lower state of charge, so I charged it and rested voltage went to 12.7

I checked battery terminals, I also took off the NS arch liner and under tray to check a wire/connector in front of the gearbox to see if it was chafed or damaged as well as those to the PAS pump having read in general searches on it that there was some issue for that connection on some cars

I've not checked any continuity for anything, as I have no info on what to check from/to, or if I did, what I should expect to see, although I have probed the pins to see where there is battery voltage, which seems consistent even if the connectors are moved around implying a lower likelihood of a break right near them, albeit a vague approach

Ok, so the voltage I noticed on the screen, dipped on cranking as they do, but did not, and never does, go above the displayed value after start if only left idling, even minutes later, but it will go to 14v if the engine is revved to 1.5~2k and held for a few seconds, where it then kicks in, every time, so I can see this most likely points to a voltage regulator issue, however, it does not directly correlate to the PAS scenario, meaning, the PAS can still work with the engine running at idle, either at a 12v state, or, in a 14v state, but in either state, it still goes off, either from the light feel, heavier feel, even gradually becoming heavier from the lightest feel if steering is constantly turned, and then if left alone for a few seconds, when repeating steering input, it is off again, as above, with or without the light

There is no battery warning light with ignition on or the engine running reinforcing a voltage regulator issue

I have run a battery test prior to charging:
IMG_5671.JPG


Noting state of health apparently good but a low state of charge, and a third of it's CCA being down

10mins later:

IMG_5672.JPG


the jump ~25% suggests a bit more than just a rested battery after several start attempts in combination with lower CCA and a 12.2v reading, 'imo'

I also ran the starter test which was ok, and alternator test which passed, but this test and the various gismo's that do them, don't have the feature to assess charge cut in time, so it passes even though it doesn't detect that the car won't charge unless revved, this is because to do the test, one has to rev the car to ~2k, so it masks the delay

I've not yet re-run the battery test with since charging

I did re-scan it though, and this time got additional faults, which are what is causing me some reluctance to just fit the new battery and alternator I have here just yet, even though they are likely to be put on, one being this terminal 30 code, I get that it might link to battery weakness but it wasn't there before with charge being lower....

IMG_5720.JPG


neither were codes like this:

IMG_5721.JPG
IMG_5726.JPG
IMG_5727.JPG
IMG_5728.JPG
IMG_5729.JPG



while these point still to the symptoms mentioned and voltage etc, it interests me why they didn't show in any prior scan:unsure:

going back to the first fault, Autel suggest possible causes and mention something specific to a 6J at the bottom, I have no idea what it's referring to:

CFFR9790.JPG


of course now the other codes showed up, which are the likes of codes I expected to see before, given the symptoms I see....

I've not yet gone into the same sections to see this sort of guidance

aware I'm going to get pointed toward fitting the battery and alternator but my reason for posting is in search of people that can actually relate to this type of symptom list, those who rather than guessing what stuff 'might' be, may actually 'know' what and just as importantly, why, they did whatever they did, repair logic if you like, or what they tested and how they proved this or that, if any such info is available

PAS I see lots of pump posts for, that's one thing I don't want to guess at really, and because of its random nature and ability even if briefly, to function, means I suspect it might not be causal, it is the main issue here, the other stuff is just things I've seen which could be relevant, it would be on a Mini for the gen1 PAS system, or gen2 for battery related codes or symptoms, but as said, I don't know these cars, so if some of you can direct me a bit better that'd be good so we can get the boy back on the road ;O)

Thanks for reading!
 

RUM4MO

Active Member
Jun 4, 2008
7,867
1,014
South Scotland
Not charging or so low battery voltage will draw out any/all random fault codes, so address that issue first.

It still sounds like the excitation line going out to the alternator is open circuit - and so the alternator needs to get run at higher revs to start working.

I do understand that you know that it looks like this especially as there is no "charge failure" warning when you turn the ignition key to the first position.
 
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