In clearing a P0460 generated by a faulty fuel level sender I now have to reset all the emissions readiness monitors before I can get a smog test. I have seven of the eight set, but the stupid Comprehensive monitor will not set. I have driven over 150 miles with 20 key cycles at various intervals (ranging from feet to 25 miles), held gears, held speeds, used every throttle position, and gone very fast and sat idling.

The evap set this morning about halfway through my driving, so I've done about 75 miles including a complete battery of "driving things" thinking maybe "comprehensive" can only be set after the seven others, but I'm not even certain that's true.

I just don't know what I am missing short of more miles and more key cycles, but as is I've done two weeks of normal driving and used well over two weeks of gas. This is costly, annoying, and wasteful. I've owned mountains of cars and never had one that wouldn't set ready after 1/3rd of this much driving.

I've read posts with Alldata's "generic set" procedure, but that just can't be right. Half that stuff is stuff that would *never* happen in normal usage. At the same time, I've read posts where people were instructed by dealers to just go drive 300 miles, so clearly doing weird Alldata stuff is not essential to setting the monitors. I read a specific post where someone, after getting that advice, drove a much shorter distance and did "like 30 key cycles" and his monitors set. There has to be more science here!

What am I missing? 10 more cycles? 150 more miles?

Argh.

 

It does seem to be akin to watching a kettle boil, but, and I may well be wrong here,


I thought it was X amount of miles, X number of times the cats have got hot enough to go into closed loop and X amount of ignition cycles.


Or just go and shovel the wife and kids ( or anybody you like ) into the car put a few hundred miles on the car taking them out for the day.


In the UK we do not have this trouble as they do not plug the car into any diagnostic machine, as long as ell the idiot lights go out and the sniffer probe up the exhaust gives an in range reading of CO, less than 0.200% HC, less than 200 ppm and Lambda is between 1.030 and 0.970 on both fast idle and natural idle, that is the emissions part of the MOT test passed.

 

Chances are you have a fault but nothing severe enough so far to set a code, and a side-effect is that the monitor can't run. Sometimes you get a pending code (as well as P1000) but it's only a computer so can't do everything.

This situation is rare but happens on pretty well any car model nowadays - it's the complexity of all the stuff in the car.

Many regions will pass a car with one (sometimes two) unset monitors.... not yours or did you not check?

 

The only monitored we're allowed is the evap not set, presumably because the fuel level has to be in a specific window to set but I don't know. I found a post from WhiteXKR indicating that, so I was patient as I used enough fuel to get into the 15-85% range and sure enough, maybe 12 miles after getting to 85% the evap set.

I was told the comprehensive must be set. There has to be some criteria for it to set, something it's not seeing. I don't think it's likely it's a fault issue as in 2 years old ownership the only CEL I've ever gotten was for the P0460, and even that was intermittent and would clear itself. Retrospectively I should have just driven around and let it clear rather than resetting it and putting me into this position. But, like I said, I've never had emissions monitors not set after three drives on any car. There is nothing further this stupid computer can learn at this point, no additional situations that are going to unfold unless someone knows something - I'm out of ideas of things I can do to it.

 

I thought I would add, just for completeness, the ECM reports no pending codes, either. After sitting on it most of the day Sunday I started thinking maybe that could be a cause of the delayed monitor setting, but the only pending code is P1000, which is expected. I'm using an Autel MD802, which I trust is accurate.

 

I have to do the same for the car I just bought, I will report back any successes- one thing I remember from the last time I did it (a month ago) was that there were some strange speeds/coasting I had to do- like drive 55mph for 8 minutes, and coast for 20 seconds as well as drive with 1/2-3/4 tank and let it idle for 15 minutes. Coasting and driving 55 for long perioods is very difficult becuase of stoplights, traffic and angry drivers so it took me some time to accomplish....

 

I spent some time at exceptionally extra-legal speeds and am sure there was some extended coasting involved following, but perhaps not enough. I will definitely give that a go. I tend to be on the gas or on the brake and rarely on no pedal. I've now driven it from about an 80% full tank to about 30% full, and I just put a few gallons in to bring it up to 50% full. That seems like excessive tank variations. If I'd had to do anything approaching that in my Suburban it would have represented like 500 miles of driving instead of 200. Grrr.

I'm now at 24 key cycles and 200 miles. I guess I'll just keep taking the long way home.... My registration was due on Saturday, so I've now paid the fees without a completed smog test. It will take a week or two for them to mail me my "incomplete registration" letter, so there really isn't any pressure at this point to get it done. If it's not set in two weeks of normal driving, I'm just going to park it on a hill. Without the brake. Overlooking the river.

 

Did a lot of cruising and coasting yesterday evening over ~35 miles to no avail. Now at just shy of 300 miles and 27 key cycles. Probably six or eight full warmup cycles. I add fuel to bring it up to about 3/4 full. Still no codes pending or stored. Still incomplete.

 

Immediately after posting that I went and did some more googling and I found this:


http://www.justanswer.com/jaguar/5se...hallenged.html#


and

www.obdclearinghouse.com/index.php?body=get_file&id=1418

Neither discuss the x308 but they do suggest there are some quirks with the Jaguar engine management that make it essentially impossible for Comprehensive to set in normal driving.

I've previously owned a pair of late '90s Volvos, and from '96-'98 these cars do not retain emissions readiness status between key cycles... every time you start the car, they have to reset. As such, they're exempt from the OBD2 portion of the smog test in California. These two facts made me wonder about my own car.

Furthermore, while there are broad exemptions that apply to everyone (like the evap exemption I mentioned earlier) which are widely known, the vehicle-specific exemptions are not. Only The Computer knows what the weirdo exemptions are for any given car.

So, based on fact and frustration I just took the car in and it passed. No need for the Comprehensive monitor to be set for a California smog.

 

Thought I'd revive this old thread!

In an act of sheer defiance, the XJR's battery died just five days before I needed to get it smogged. Through normal driving I added about 80 miles but it was not enough to set the EGR, evap, or comprehensive monitors. I know I don't need to worry about the comprehensive monitor anymore, but the evap and EGR are critical. So I drove it another 300 miles. The evap set, but the EGR did not. I drove it another 100 miles. Still nothing from the EGR. So I reset the ECM ("cleared codes") and started over. Six monitors reset within 40 miles of "intentional" driving... but EGR is still not set. So I drove it another 50 miles. EGR is still not set.

There are no pending codes, there has been no CEL in years. I have tried all the tricks suggested on the internet in terms of distances, speeds, throttle positions, gear selection, etc.

Anyone have any ideas?

 

Do you have a device (blue tooth or otherwise) connected to your car that continually monitors and displays data?

 

Yes - that's how I know the monitors are (or are not) set.

 

I’m on my third X308, second XJR. My experience with all three is that with my blue tooth device connected I could drive forever and never get P1111. But, if I disconnected the device and would drive 30 or 40 miles, BAM, P1111. When I would hook it back up I would discover the resistant ones would have completed.

I cant explain it, but for what it’s worth that’s been my experience.

 

That's really interesting! I am not driving with it plugged in constantly, but am checking it every 30 minutes of driving or so. Maybe consistently checking it is having this effect.

Interestingly, my first attempt took nearly 400 miles to set (sans EGR) - though I went on to drive another 100 without success.

My second was set within 80 miles (sans EGR) - though I did another 30 or so.

I reset it again this morning. Six were set within 20 miles. Still no EGR.

Anecdotally, it sure seems like if you "clear codes" before setting out, they set MUCH faster than if you just disconnect the battery. That's something, at least I don't need to burn 10 gallons of gas to get the first six to set.

I have had cars with problems setting monitors, but inevitably it was tied to a known problem... an Isuzu that wouldn't set its cat ready, but was prefaced by a bunch of cat efficiency P-codes or a Jetta that wouldn't set its evap ready but was prefaced by a known evap leak. These cars all needed repairs, indicated as much, and wouldn't set ready. BUT, in each case, after 80-100 miles the engine management would give up and throw the expected CEL. I don't know why the Jag will neither set readiness nor an CEL. Without the latter, it's unclear what I should even look at. (Not that I expect an actual repair is needed - there have been no EGR codes ever.

I have tried dozens of random drive cycles. Most entail low speed to high speed (eg 0->45mph, or 20-55mph) with a period of steady throttle then a period of coasting. Some involve manually selecting gears, or using lower gears to keep revs up. Most require repetition - 3-5 times. I am going to try three more today:

0-45mph @ >50% throttle
repeat three times

0-50mph, steady for 15 seconds, stop
0-40mph, 4th gear, steady for 30 seconds
40-50mph, 5th gear, steady for 15 seconds
Stop for 20 seconds
Repeat five times

45mph, steady for three minutes
Coast to 0mph
Repeat three times

I understand conceptually what this monitor is trying to understand, and it feels like all the "light throttle cruise for a period then coast" I have already done should set this monitor. I'm not sure what else it might wanna see. :

 

PROGRESS.

?

I had no luck setting the monitor in another ~200 miles. Yesterday, I asked my parents (retired!) to take the car up to Tahoe figuring it would be a great mix of driving.... Highway 50 has a lot of twisty roads and elevation changes that result in speeds between 25-65 and lots of acceleration and coasting. At 100 miles in each direction, it's a lot of variation! Plus, I was hoping that a different driving style might give it what it needed.

They made it up, rested for 45 minutes for lunch, then headed back. About 4 minutes after leaving, the CEL came on along with RESTRICTED PERFORMANCE. I had them shut down and restart, which cleared the warning but not the CEL, so they headed back. The trip back was uneventful, and the car behaved normally.

Codes pulled were P0172 and P0175, so rich in both banks. I had these codes quite some time ago and they only appeared once. At the time, I thought they were related to a serious drivability issue, but that issue has been long solved. I'm really curious to know what my dad did in 100 miles that I could not do in nearly 700 miles to get that code! Maybe the elevation...

The freeze frame looked like:

Code: P0172
Calculated Load: 62.4%
ECT: 208F
STFT 1: -11.7%
LTFT 1: -13.3%
STFT 2: -9.4%
LTFT 2: -15.6%
MAP: 8psi
TPS: 15.7%
MAF: .07lb/s (=~33g/s, =~50hp)
IAT: 90F
VSS: 24mph
RPM: 1555rpm

Obviously those fuel trims are out of spec, so the CEL is not a surprise.

The ECT, TPS, VSS, RPM all make sense as they had just moved out of a parking garage onto a busy surface street. In watching the OBDII scanner for 700 miles, I've never found this to be inaccurate.

IAT could be accurate. Ambient temps were ~50F, but the car had been heat soaking after a long drive and it is supercharged, so elevated intake temps seem reasonable. With the car off and cold, IAT does show roughly ambient temps, so I'm inclined to believe it's correct. It's appeared accurate over the recent testing.

MAP I cannot verify, but it does show 14.6psi with the car off (atmo, correct), and it does remain in single digit numbers at cruising (high vacuum, correct) and it does move into double digits under throttle (boost, correct). I think I can trust it - but I am going to test with a vacuum pump this afternoon.

Calculated load and MAF seem wrong to me. I would not expect a calculated load of 62% with a TPS of 15% at 24mph. Over half the engine's capacity to creep along in traffic? .07lb/s airflow is similarly a lot - I would expect to see that sort of flow for much higher speeds given that TPS value.... or a much higher TPS value for that speed! Like, cruising at 55mph might use .07lb/s or brisk acceleration from low speed. An incorrect, high MAF value could result in high calculated load, so there is a correlation there. That also nets a rich mixture.

Additionally, I am aware of a couple EGR strategies, including using TPS, MAP, and MAF in combination with or through calculated load. Calculated load can be used to schedule the EGR valve, so if CL is high, the EGR may not be scheduled. Also, a common monitoring approach is watching MAF values fluctuate with the EGR opening and closing - eg, the EGR valve opens so air flow through the MAF is reduced, and the EGR valve closes and MAF readings increase.

The takeaway is that a bad MAF might cause high CL, rich running, lack of EGR scheduling, and ineffective EGR monitoring. It is similarly possible that the MAP or TPS are the culprit - they could also cause EGR and mixture problems - but I can at least to some degree test those... the MAF not so much.

I don't feel 100% about it, but it's at least a direction. I am definitely finding the limits of my scan tool on Jags in this pursuit... I have gotten used to factory tools for other cars that I have.

 

Within all the limitations of info the above gives, the MAF reading seems not too bad, maybe a bit on the low side for 1550 rpm.
As a reference, it should read some 39 gm/s at 1500 rpm while in D for a N/A, and I should say that should also count for a S/C at that rpm.
A low reading MAF should give you lean conditions though.

You really should see what is happening "live", not just a freeze-frame.
Work your way systematically through the various systems.

 

I'm all ears if you have some suggestions...

There are only a few things that could cause rich running in both banks...

 

First things first: You will need to be able to log readings, or at least read them live while driving.

My best practical experience is using Torque Pro on my phone, and set up the gauges with the format where they list the highest and lowest values recorded.
Below an off line screenshot of one of the several pages I have active.

Then, if you want to go into more detail, you can log readings within Torque as well.
It is a bit limited, but will do.

Then, as a starter, I should check the MAF readings at the various speeds / loads, not only raised idle.

Also, be sure at the MAF wire connector.
There have been other cases (incl. my own) where the connector was slightly loose, resulting in erroneous readings (but only sometimes).
Cleaning out, bending the pins slightly, and some connectivity gel solved my rich running ever since.

Finally, as you mentioned, there are few other (shared) components which can cause rich running.
Drive the car, have a look at trims and CAT's at various loads, and you should be able to work your way towards the culprit.

 

I am unfortunately way past that. I have a $1000 Autel scan tool which I have been driving with for nearly 1000 miles. As mentioned above, I have not been driving with it logging full time, but I have hundreds of miles of data collected with it. The difficulty is that there is no way to accurately correlate OBDII air-related readings with actual conditions. I can observe MAF or MAP for response, but I cannot ensure that X g/s or Y psi indicated is factual. I can reasonably assume that 208F ECT readings are accurate on a hot engine, and I can reasonably assume that 15% TPS correlates with light throttle, but inaccurate MAP and MAF are not so easy to vet.

The symptom was of course an EGR monitor that won't set... and unfortunately the one thing it appears my scan tool can't do is report EGR scheduling so that's a black box to me. If I could graph EGR scheduling with MAF/MAP/TPS overlaid I would probably know more. Now I have a pair of rich codes to help provide direction - there are ultimately very few possibilities for two banks reporting rich.

Yes, but this only tells you if the MAF is responsive, not if it's accurate.

Yes, BTDT as well. Pins were removed, expanded and reinstalled about a year ago chasing another, unrelated issue.

I'm not sure what you mean by CAT's - catalytic converters? They are operating efficiently and passed monitors quickly. STFT is always good - low single digits - but LTFT is generally high, approaching 10% and, as seen in the freeze frame above, sometimes higher. But I know the car is running rich... I'm trying to determine why.

What I have is high negative LTFT (rich), no EGR monitor, high calculated load. I have TPS/ECT/VSS/RPM/IAT which appear accurate. MAP which appears accurate but it ultimately an unknown. MAF which an unknown. I have a year old <2000 mile air filter, a two year old <3000 mile fuel filter, good fuel pressure (at idle, it's not electronically monitored), and a car that otherwise runs great. O2 sensors look good (good voltage) and pass monitors quickly.

Maybe you see something I have overlooked? I really appreciate the thoughts!

 

I'm thinking the same as you. Sorry, that's no help really but I'll try to throw some ideas around.

I know you know this stuff but maybe it'll nudge something... The PCM has trusted various sensors (you've listed many) and decided the fuel it wants. Then triggered the injectors to get it, partly trusting a fuel pressure sensor (well, I'm guessing here as I don't know this specific car but on my 4.2 there's IP for injection pressure).

I wonder if injectors may have dribbled slightly. I don't see how that would be rich on both banks, though.

A blocked cat can cause the wrong back pressure and oddities but again I don't see how that shows up as both banks.

I have seen weirdness with a failing battery but I gather yours is near new.

I seem to have missed the car details - XJR, but which year?

Is it a returnless fuel system (as mine)?

Any vacuum hoses to control fuel / fuel pressure / etc?