Go figure. After posting yesterday about fueling issues on this and the x100 forums, here I am today.

I've finally been driving this 2004 XKR. Today I went to the gas station to fill with the pump for the FIRST TIME. Up til now was using a gas can. Anyways, I'm pumping in gas and pressure is building up and blowing the gas back up the spout. Beyond that, when I remove the gas cap I get a lot of pressure, blowing OUT, I believe. I was getting a p0450 emissions code, that has since stopped but I KNOW it will be back.

Trying for a fix (which seemed to fix the first time ever p0450 DTC) I removed the cover for the fuel pump and tank looking to see if there was a pressure release valve that had become hung up. I removed the cover assembly and changed the BLUE section of the assembly with spare bits I have and cleaned things up. Went back to the station and same issue. That's the first Strangeness. Anyone have any ideas on what would cause something like that I'm all ears.

Is there a purge valve of some sort in the front LH wheel well under the liner that might be causing this?

For the p1646, I have looked in the forum and I am a little confused. The code seems to be related, according to threads, to two things. O2 sensors and Emissions System stuff to do with the EVAC system and recovery systems...? Which is the correct spell out DTC for the 2004 XKR when hit with a p1646? I'm skerd to know.

I have ALWAYS had a heater circuit code, p0057 for bank 2 sensor 2, and I plan to change that sensor (I wasn't stressing it) next week. Since I'm driving it now, would the 02 Sensor p0057 trigger the p1646 code? Are they related? I kinda hope so.

If anyone can help me or shed some light in what I'm looking at I would greatly appreciate it. Pretty much stumped here.

Thanks

 

FWIW, the 2003 (I'm not aware of anything more recent) guide shows this:



By this time there were two separate HO2S relays, one for each bank, so I don't believe the codes are related other than that it's possible the sensors have suffered from getting wet.

Here's the pinpoint for P1646 from the 3rd edition manual:

 

Good Morning, Michael... Thank you!

Ok! That's some great info! You probably remember that I really struggle with stuff like this BUT, I will try my best to run throught these testing procedures. Key word, try. Intimidated already...

So, this is all 02 Sensor related? Or it's wiring. Or, GForbid, an ECM thing...?

I've had this thing running (idling mostly) a long time. Not driving out on the road til this week, but running, and I've never gotten this p1646...always had the p0057.

I ran it thru the car wash for the first time!
Could something have gotten wet?

In the original post I foolishly forgot to mention (an import fact) that since the p1646 code the car runs in open loop. The message along with the message saying it's in open loop is that the temperature is toooo low? This, while the coolant temps are 200degrees +.... 206, 209...

The exhaust system is greatly modified. No rear or mid silencers/mufflers. Under axle pipes. The downstream O2 sensors are super easy to get to and there is no doubt that they were soaked under water when the car sat up for a long long time after it's swim. But, the uppers I don't think got wet or were wet long. When I first started the car a torrent of water shot out both pipes...

Ive got to get this sorted.

All ears over here.

 

I still have the tests to perform but at this point it looks like I have ZERO 02 Sensor function. Out O the blue. Strange.

This is what I see.


Just cleared codes, hence the incompletes

 

It's as you'd expect bearing in mind the Open Loop situation.

 

I'll attempt to explain - my apologies if I've missed the point - and JagV8 will rightly jump all over this if I'm wrong...


The ECM carries an internal 'list' of fuelling values that are based on engine & speed, load, etc. Fmertz has posted a picture of this 'map' on the forum somewhere.

In a normal situation, the ECM will determine how much fuel to deliver based on feedback from the various sensors (closed loop). If it decides that the information it is receiving from those sensors is duff, it will default back to that map to allow the car to be driven (open loop).

Your reader is reporting faulty sensors with the P0057 and P1646 codes. The additional 'Open loop due to insufficient temperature' is an interpretation added by the reader. It may be saying that the HO2S sensor isn't initially reaching the correct temperature sufficiently quickly because its heater has gone on the fritz?? I don't know.

I'd be tempted to disregard the reader's interpretation and focus on Jaguar's as per JTIS.

The P0057 as 'pending' implies that it's intermittent.

My thinking would be sensors (they do wear out), wiring (it can get damaged, corroded), followed by ECM last on the list.

 

Thank you both...

That pending p0057 code is constant and current... Lol, it's the only thing that's been consistent with the car - haha. From day 1. It will return to red soon enough.

With the p0057 code, being the heating element only I think, I did used to get trim values from the bank 2 downstream sensor, always did, until yesterday. I'd never seen the p1646 code before yesterday... Does the p1646 code basically mean, is it saying, that all of the system is shut down due to bad values from the O2 or other sensors?

I checked the 02 Sensor connections today, visual-ed the wiring and nothing seemed amiss. Unplugged and replugged all the sensors thinking maybe it was a crud in the connector thing. They all looked spanky clean...

I will be replacing the downstream sensor when I come back from the coast. Read and reread those directions
I understand there are tests, but I guess I'm NOT clear what the p1646 actually means is at fault... All of the sensors, some of them? Does it mean the ECU basically gave up in trying.

This started after a car wash... Maybe I got water somewhere it shouldn't be. I looked around and didn't see anything

My goodness what a PITA

 

Hi,
P1646 is pretty specific to the bank 1 upstream HO2S sensor.
Perhaps the combination of that and the bank 2 P0057 error is sufficient for the EMS to decide to go open-loop and use the default map?

PITA, yes:- your take-away is that you started with a flooded, dumped-in-a-corner car that you can now drive. Take a step back and look at what you've achieved. These odd errors are part of your journey

 

Oh sure... I'm a happy camper (literally, tonight), definitely still learning, definitely having a good time and definitely pulling my hair out...

Bank 1 Upper! Alright!

When I started with the "Stupid Red Car" or "The SRC" as me and my lady call it, the doggone thing had NO floors and had had a fire... On the road.

Michael. Thank you for putting me on and keeping me on the right track... 😊

I'm so busy with these things - I definitely don't contribute as much as I should to the forums. I take more than I give. And that ain't cool, in my book...

​​​​​aka The SRC....

 

Could I have,,,,,? Omgoodness

When I was swapping in and out bits at the fuel pump assembly (the blue section in top that deals with EVAP), when putting everything back together, I put a SLICK of,,,, wait for it,,,, silicon lube on the 3 hoses that connect the blue assembly so they would slide over the barbs easily...the smallest amount.

I know that silicone will destroy O2 sensors...

After, and now, today, I get ZERO readings from all for O2 sensors. Trims and all stay at ZERO on the obd in open loop.

Could it be that small about of silicone in the EVAP system that fried the O2 sensors?

 

I'm reluctant to believe they'd all be entirely trashed at the same time. I'd be trying to find another explanation.

Er... in OL (open loop) the PCM is allowed to report 0 i.e. need not give a true value... you may want to look into why it's OL.

 

That's what I'm trying to do....Trying to figure out why I went from a car the was trimming correctly, to suddenly not. I had messed around with the EVAP stuff, and that's about it. Got codes p0450 (gas cap) since gone, and momentarily a p0193 which since disappeared - which all seemed to happen at the same time as the p1646... I can't figure it out. Maybe it takes 3-4 cold to hot drive cycles to clear. Making me nutts.

Michael sent me a detailed diagnostic set of tests to troubleshoot the problem. I haven't gotten to do it yet - I struggle with stuff like that...

So I've just been thinking WHAT it might be.

I too have a hard time believing that the (it's completely orderless) silicone grease would fry all four, or do enough damage to trigger the code and give me what I'm seeing

Time will tell. I'd hate to start swapping O2 sensors if that's not the issue.

 

Hi Jay,
From what I read, it's [the solvent in] volatile silicone sealants (RTV) that can cause damage. Hard to imagine that a squirt of silicone lube around the outside of a fuel line joint would contaminate to any extent, but I'm not a chemist.

As JagV8 says, in open loop, the ECM isn't making any active corrections to the fuel/air mix so reporting would be meaningless since it's working from the default fuel map.

I believe you can swop the sensor connections across and look for a code change to P1647 (after clearing the P1646) in order to confirm a dead sensor.

 

The solvent...! Damn good point. There is something very different in an RTV type silicone gasket sealer - which I have heard can cause problems - and the ever soft silicone grease. Makes no fumes as far as I can tell.

I will swap the plugs...thank you.

Yes. I read alllllll zeros on my obd. ZERO for everything.

Even after I swapped the engine in the XK8 some months ago and had the O2 sensor issues, when completely pegged out, maxx values in stft, and the car had gone into open loop, if I remember correctly I still saw numbers moving around on the obd...

 

Some of the RTV solvents are pretty aggressive, even if they do smell like they'd be good on your fish & chips

I have a tube of neutral-cure from my ABS module fix since I'd read that the normal stuff can be detrimental to circuit boards.

 

It was a good morning, and some good news.
I never said I was a genius, hahaha....omg
​​​​​​So yesterday, driving the ol blu bomber around I stopped to fill with gas. NOOOOO GO! The car wouldn't take any. Fuel would fill right up to the filler neck and go near no where. There I am, at the pump, scratching my head - but I'd seen this before. I got a needed gallon in and went on home.

This morning I got up headed to work, laid on the side of the car and twisted and turned the hose going into the carbon canister til it popped out. A pressure fit sealed with an oring, held by an expanded 4 prong fitting clip in type thing.

SWAMP WATER came ah pouring out of both the canister and the hose!!! Lots... Stoked, I headed to the near Mobile Station. Filled her up NO issues. I disconnected the other side and will leave it that way for a little bit.

I think I got a smoother ride due to there not being negative pressure building up in the tank and fueling system...

Yeah, I'm no genius.

Wondering why I didn't just do this right off...?

I'm hoping that this will solve the p0450. Time will tell.
P0450 Evaporative Pressure Sensor Fault.

 

So here's a question, and I haven't reattached the hoses to the carbon canisters, I'm hoping some air will do things good. I also haven't cleared codes or anything.

Q: Can the p0450 code and complete disfunction in the EVAP system cause the p1646 code and base map fueling?

 

So after work, after less than a day, I pulled into a gas station, reached under the car and plugged the two press fit hoses to charcoal canisters back in. I know they can't be dry inside yet. Anyways. I wanted to test to see if the issue of back pressure in the tank that was resolved when they are discon/unplugged had lessened or been resolved after all that water poured out. No dice. Still struggled to get fuel into the tank... But it was better. I removed the hoses again and headed home.

Looking around I found the diagram below. Seems the p0450 code is a code for the fuel tank pressure sensor? I believe the little black plug in on top of the blue fuel pump assembly at the tank. Part number LNC1624AA...?

But, I don't believe my problem is with the sensor. I think it's telling the truth, doing its job... I think it's to do with a clogged EVAP system at the charcoal canisters... I plan on removing the canisters this weekend and seeing what I can do. Dry them, or if they need replacing, or if air can be blown thru the lines, or what...

 

Good stuff today. Hot on the pavement tho...

The tank pressure sensor was doing its job...

Crawled under the rear end and removed the two carbon canisters... Literally 5min each. One was sweet and clean, the other a mess. The clean one, there was this awesome substance in the canister, this completely clear, slightly foamy, slightly viscose stuff. Stuff that I'm guessing accumulates with use over time. A petroleum by-product I've never come across. So interesting I stood there examining it for a while. Fragrant smell, kinda lemony... Slippery.

Anyways. The other I pried open. Cool set up. Absolutely packed with carbon pellets. There is a medium length plastic post with a plastic/nylon wool sheet covered by an aluminum or tin plate captured by a push fit fastener that packs it all together. Well designed. Dumped all of the pellets into a strainer and rinsed, dryed it in the sun on a slab of cardboard and refilled the canister. Then, epoxied the cover back on and reinstalled. Solved the p0450 code I got when I started driving the car. The p0450 didn't appear til driving. Never showed up during idle in the weeks and months I've been slowly working on getting this thing back together. A good day.

Went for a nice drive out in Jersey after and so far so good.

2 O2 sensors and I should be done with codes.

​​​​​​



Top cover that pries off pretty easily...

 

Nice when things come together,,, when they do,,,

At the risk of jinxing myself!

Replaced the upper RH O2 sensor and downstream LH O2 sensor yesterday after work. Thanks to the exhaust mods via PO, the job took just 30min... Everything came right back on-line. Nice.

I'm sure there will be more surprises coming.

I had been all kinds of confused about a p0193 code but as soon as the car adjusted for the new sensors the p0193 disappeared. Connection between the O2 sensors and fuel pressure???? I still have a bouncy fuel pressure according to the OBD reading but it must be staying within the cars spec for fuel pressure. Maybe this will find it's way back to 55.xx PSI as well, over time. Funky car, the Jaguar.

Strangely, I'm still having trouble filling the tank, at the pump, and just letting the nozzle run. It's MUCH better than before but I'm still getting back pressure.

But - never seen THIS B4... I am pleased.
Looking for the BIG P1111 !