99 XJ8 I am getting codes P0172 and P0175 and it seems to me as though I am going through gas quicker than usual. Recent transmission replaced with one that has 15k replaced engine a few years ago has 60k on it now. I have also noticed that my speedometer is showing how fast I am traveling. But, where you can see trip info this is showing incorrect average speed. when clear I can be going freeway speed and it reads in the 15-23. No, this is not reading the mpg I am wondering what would be causing this and would that have anything to do with the codes? Also when at freeway speed and maintaining it is a little rough.
Appreciate your help, thank you.

 

Not to hyjack the thread, but is there a listing that explains the different codes?

Just cleared a P1000 myself. Message center said gas cap.

 

ant:
You cannot clear code 1000. It tells you that the OBD drive cycle has not completred since a rcode reset. You change code 1000 to code 1111 after completeing the OBD drive cycle.

 

Sparkenzap is right on the p1000 (system checks not complete) it does not clear until it runs through a complete drive cycle, then becomes a p1111 (system checks completed since memory clear), if you have a scan tool not dedicated to Jaguar the description may come up with a maf failure which is not correct, always get the code and check it to the JTIS manual then diagnose it.
Anyway....
the two codes you listed
P0172 is bank A combustion is too rich and
P0175 is bank B combustion is too rich

The fact both sides are running rich you should be looking at something common to both sides of the motor.
With this info you gave in the fourm and the codes listed, it seems to be getting to much fuel, it may be a failed fuel regulator causing higher than normal fuel pressure or blocked fuel return line restricting the fuel back to the tank could also bring up the fuel pressure at the injectors. You pretty much need to check the fuel pressure at the rail to check for any of these failures,if the pressure drops within 15 minutes you may have a leaky injector that would also cause a rich condition but I would think you would have to have at least 2 leaking ,one on each side to explain the rich condition on both banks.
If fuel pressure is normal and holds pressure , Look at the air intake system for blockage it could be as simple as a clogged air filter . I did list that in the wrong order, You should always look at the simple stuff first, Check for blocked air flow first then look at the fuel pressure, Look at the basics always!!!, no mater how complex the engine, proper air, fuel and spark is always needed first, the fact there is no other codes would makes me think that all the other engine control systems should be working and O2 sensors are just seeing too rich a fuel mixture.
Start there first.then we can go deeper.
Keep posting and I am sure we can guide you to get your x308 running normal
Also I would not drive it too long with the rich condition , you could melt up the cat converters,and create more problems
Any other things you can post that may help if you dont have any luck finding a problem with the fuel or air flow will help.
Any recent repairs? ,or any repairs before you started having the engine light and bad fuel economy?? Was the problem there right after you changed the trans?, or did it run normal after the trans was instaled for some time??Is there a misfire under load or hard start/long crank in the morning?
Answers to some these qustions could help lead us down the right path.

As far as your trip computer, ignore it!!!,It does not control anything in your powertrain, that just monitors your powetrain based on a lot of variables and they are never completly accurate they are good for estimating when you don't want to do the math.
My 2000 xj8 said I Average 23 mph , and I know that is not right.But the other averages on the trip computer are pretty close when I check it the old fashion way .

keep posting your progress
Scott

 

Was I suppose to drive the car while I had it connected?

thx

 

Ant:
No- not needed. What happens is that when you reset the codes, the computer remembers that that event occurs and does not give a clean bill of health until the engine has been put through it's paces enough to say all is OK. Google "OBD drive cycle" for a better explanation. You need to drive about 50 miles with steady 35 to 45 mph cycles and the gas tank between 12 and 3/4 full, as I recall , to get the cycle done.

 

These error codes came on after the transmission was installed. As far as my mph average was dead on also before repairs. I am wondering if there is a sensor that is not connected right and could this be be change the problem?

 

IC, I had a stall at a stop sign under hard acceleration.

Got this P1722:

"P1722 Transmission stall speed failure Drive vehicle from stand still; accelerate hard Y 2 @F [A, M] When fault is detected:
– TCM adopts transmission
electronic limp home mode (5th gear)
– ECM limits engine power Transmission oil level low
Selector cable adjustment / installation incorrect
Output speed sensor problem
(Refer to P0721 Possible Causes)
Transmission mechanical failure"

happened once before.

tia

 

i am having this issue too and the only thing done was changed the driver side upstream o2 sensor...so I will start checking tomorrow and cleaning the airways...i have a new fuel pump and all was fine until that o2 sensor went out

 

No-because after a short while the car will throw up fault warnings, then eventually go into Restricted Performance mode, followed by certain dash instruments not working. This happens in fairly short order & will be 'most disconcerting' if you happen to be in traffic flows at the time...

Ask me how I know

P1000 is completely normal, and it just means the system hasn't gone through the full cycle of drive tests. Once it's done that-and it will only be completed fully if the car is driven in a manner that allows certain functions to be tested for the procedure-then you will get P1111, which means the driving cycle tests have been successfully completed & everything is fine & hunky-dory.

Do not drive the car on the road with the scanner connected, because it will raise your heart-rate when the system 'throws a wobbly' & you are in the middle of heavy traffic with an unresponsive car