I've gotten a couple of codes of late. The first was P0174 which I have seen before when the gas cap wasn't tight enough but ... I think it was on tight this time. I got it during an emergency acceleration move when I was going around a car at lower speed say 25-30 mph and all of a sudden the car bucked like hell then threw the code and went into reduced performance mode. I subsequently read and cleared the code then attempted several similar acceleration test and nothing ...

But subsequent to that many days later it threw another code p1647 While gingerly driving around. I read and clear that one which I beleive is the front oxygen sensor on the left.
I got one for the right earlier this year and replaced the sensor but that one I couldn't clear.

I took a drive of about 100 miles WO incident and I was using the car at my remote service garages all day getting tools and supplies out of the trunk and passenger compartment so the interior lights were automatically coming on frequently. At lunch I got the p1647 once again.
The reason I'm curious about the battery is that earlier this year when I did the electric parking brake reset maneuver the battery was too weak to execute it and I had to use a jump from another car. Then it worked fine and everything on the car has been fine ever since till these two codes popped up. I don't mind replacing Oxygen sensor if it's legit like the last one but I am curious about these codes this time and I'm suspicious that I really need a new battery instead? These cars seem to be very sensitive to any sort of battery issues. The engine cranks just fine but I know that's not necessarily enough.

 

Yes it can. We have found in Britain that the alternator on the s type was designed for the older type of batteries. The newer maintenance free batteries require a permanent charging rate of around 14 volts. Our alternator only produce 13.5 volts for around 5 mins. This means that the battery is only charged to around 80% of capacity.

Do you have a volunteer to check it. I normally charge mine for 24 hours using a smart charger. Then I turn the lights on for three minutes to remove the residual charge.

The reading you should get is 12.6+ volts if you get lower then your battery is slowly beginning to go bad. If it reads 12 volts then it is technically for all purposes dead.
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+1 on normal cranking speed not being a valid determination that the battery is good.

If the battery condition is suspect, given the chance to spend your time and money, I'd spring for a new one as a baseline to see if further troubleshooting will be required. Put the new battery on a charger overnight, as new batteries typically aren't fully charged when purchased.

You may find this thread of interest, specifically post #8 where a known-bad battery was installed:

https://www.jaguarforums.com/forum/s...3/#post1038396


This may not apply in your situation, as I'd expect to also see EPB/DSC/Cruise faults, but who knows.

 

I have the same exact battery in one of my vintage cars and that one is much younger, hardly been used but is on a 24/7 smart battery tender. I think I'll take that one out as the car is apart at the moment and see if it's in better shape than the one in my Jag. I replaced that one because the newly installed electronic ignition (Pertronx) wasn't functioning properly with a really tired battery. So similar reasons.

 

Well a much newer battery with a higher voltage (12.89 vs 12.49) didn't do the trick. So it's on to replacing the oxygen sensor.

 

Before you go out and buy a new sensor check the fuel trims first

You may find it to be a different problem

Watch this YouTube vid he explains what you are looking for.
https://m.youtube.com/watch?v=5WnM_NsOtd8

 

First forget about your battery. The p1647 is for bank 2 upstream o2 sensor heater element. It needs to be replaced. You can swap side to side to verify but the element is just like a light bulb, they burn out.
Your p0174 is a lean engine not a gas cap. And the bucking on accel is because its so lean its causing a misfire. And bad enough to go into restricted performance to keep from damaging the engine. Lean burns holes in pistons just like a blow torch in steel. Neither of these issues are a weak battery. They are exactly what they are

 

+1 on ignoring the battery for the moment. Look for vacuum leaks on Bank 2 and correct P0174. Check for leaks at the injector seals and inlet manifold to supercharger seals. May also be a faulty injector.

 

The O2 heater circuit is likely open circuit - check with a meter. Quite an easy O2 to swap. I posted about replacing one.

 

Oh yeah, who's the chucklehead that even suggested otherwise? What a mouth-breather, huh?

BTW, don't read post #3. No reason...

 

hmm, a P0174 and later a P1647 is hardly a sign of a bad battery.

I'd start with the O2 sensor in case it was going bad enough that it caused the fuel trims to be wrong.

A bad battery really seems to flag weird and unrelated codes.

 

Yes I'm aware of what code means. I replaced one earlier but this one is a bit different this time. It's not been a hard fail like the last one was which I why I posed the question about the battery which as it turns out needed replacing anyway.

The p0174 is a very elusive code on my car. Typically when I've checked the gas cap has been loose. Then it doesn't return. This time there was indeed violent bucking, I assume because I got the code just as I asked for power. I have cleared the code and driven the car hard for a couple of weeks and no code ...

With all due respect I'm not going to chase once in a while issues like this. I could go crazy and or broke doing so.

Whereas the p1647 is returning very quickly and with a new battery I'm ready to think that I needs replace the oxygen sensor. The last time it was a 100% open circuit. Maybe this one is intermittent or has finally failed hard. I was never able to clear it the on the other bank.

 

That's OK plenty of folks on here think they always know everything. I've been around the block on stuff like this with mechanics and doctors with much more training and education and experience and they ALL get it wrong at times. I think the P1647 may be a heating element that has an open circuit after it gets warm. Just it guess but that fits the evidence much better than the last one which was a nice hard failure and easy to nail down. I always pray for the easy fixes like that. But the p0174 is quite elusive. It too could be something developing very slowly but it sure is GD slow!
I can wait.

When I first got the car and was still under warranty it threw codes that indicated it needed a need air flow sensor but they had a devil of a time eliminating that code and neither they or anyone else has been able to solve the slight leaks on the GD coolant tanks even with 3 tanks, all new hoses and caps.

So I'm ready to listen to alternative ideas when the obvious ones aren't quite so obvious.

Thanks.

 

Thanks to EVERYONE that's posted too! The oxygen sensor will have to wait till spring the car is going into storage very soon now.

 

Winter in the northeast.lots of ice and maybe salt to deal with huh. A long winter nap for your cat. Break out the awd or 4x4

 

It's not really a very good winter car and that's a very quick way age it. I'm amazed at what people DO drive in the winter here though.I suspect most are on a 3 or 4 year lease and they don't give a crap. Suburban time ...

 

We get neither the frequency nor the volume of snow here in central North Carolina that you do in New Jersey so our vehicles can be driven all year long. My now-sold S-Type 3.0 always remained safely at home whenever the white stuff flies and so does my wife's XK8. Her recently-acquired Lexus RX350 daily driver will also stay at home during our snowfalls. Our trusty 2013 Subaru Outback 3.6R is a fantastic winter vehicle (as well as our primary dog-hauler and my current daily driver) and it never fails to get us wherever we need to go and back home safely regardless of the prevailing weather and road conditions....

 

Always nice to have an extra 2 wheels under power in the crap weather. Especially if you have posi lock rears. I have a 2000 Silverado 4x4. Don't use 4 wheel much but it is sure nice when needed. Call it my little mule