02 XJR
Screenshot of what comes up. I did get a breif "retstricted performance".

 

Clean the MAF first? Check vacuum going to the fuel pressure regulator. Can you read coolant temperature from the ECM?

 

If my memory is correct, I believe the IAT is in the MAF? I do have a new oem one just incase it's bad. Yes, I can read coolant temp. It was 200°F which has to be correct, because the fans were running. I'll verify what it reads on ambient when cold starting.

 

P1111 is a GOOD THING!
Something I wrote years ago. YOU cannot clear a P1000.
The readiness monitor will change that to a P1111 when all are complete.

Either DTC P1000 or P1111 will always be present in the ECM!!

P1000 circle of insanity

The P1000 code is present when the ECM has had all DTCs ‘cleared’ from the non volatile memory or the battery power to the ECM is interupted.

The P1000 is changed to P1111 when the readiness monitors are completed by a specific ‘drive-cycle'.

People often see the P1000 DTC and try to clear it. This resets the DTC to P1000. (again)

Then the car is driven until the monitors change the DTC to P1111. (some guides reference this as a fault with the intake air temp sensor)

Jaguar P1111 is just the ECM ‘being-happy’, not a fault.



People see the P1111 and decide it must be a fault and clear the DTC.

The ECM now defaults to P1000 and the circle of insanity continues.

Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.
Then the car is driven until the monitors change the DTC to P1111.
The code is cleared and it reverts to P1000.

 

Bob, he probably knows about the P1111 code with the exception of the intake air temp sensor which is listed with the P1111 which in itself is odd. The rich codes could also be dirty injectors or a FPR gone full zero vacuum which raises the pressure as you know. Brandon, can you get STFT and LTFT data on your scanner? Also, which code reader are you using?

 

Yes, I can read the short and long term fuel trims. Im usinIm"Car Scanner" which is an app for your phones. Using a Bluetooth obd2 port.

 

P1111 is NOT a DTC (fault) on a Jaguar.
I think it might be for a GM car? but NOT a Jaguar.

Everytime I get a P0172/P0175 it turns out to be a MAFS problem.

 

I think his OBD reader is simply attaching an incorrect message/description to the DTC.
I have a not so cheap, Autel scanner with unique manufacturer DTC. But I have noticed some discrepancies on the description attached to the codes. So I read the code, but verify what it actual means by looking it up in the Workshop Manual.

Jeroen

 

I used a friend's Autel and was pretty impressed. Which one do you have? I don't mind paying for something that warrants it.

 

What about a P0174 code, what does that turn out to be?

 

P0171/P0174 are lean codes. Usually a leak somewhere in the intake downstream of the MAFS.

Could also be a fuel injector issue?

 

I got the MaxiDiag Elite. I bought it about 4-5 years ago here in the Netherlands. Then about $350 or thereabouts. When I still lived in Kansas City, I had the AutoEnginuity package, which ran on my laptop. That was pretty good too, but hugely expensive. In 2009 I paid, from memory, $500 for the basic package and $500 for the Jaguar add on. (yes, ONLY the Jaguar package for that money

With this Autel scanner, I get essentially all makes/brands/models, all codes and decent live functions as well. It also includes a service interval reset. I still get the occosional update as well. So they are still adding new car models.

It serves my needs fine. If I ever upgrade i would go for something similar. But I would want to have a few features for modern cars. E.g. for working on brakes, like bleeding for instance, on many modern cars, you need to be able to manipulate the ABS system and so on.

This little device has saved me a lot of money:

https://www.team-bhp.com/forum/diy-d...ml#post4467801

Jaguar ******* would have charged me for replacing the throttle body. I managed to fix the problem with a 2 cent (if that) tie wrap. Has been good ever since!!
The little lug holding the connector on the throttle body had broken, so it was a wonky connection, due to the connector not fitting properly.

Jeroen

 

The last time I got these codes(a little over a year ago) it turned out to be the MAFS connector. I would wiggle the MAF wiring harness. It would idle odd for a split second, and would run fine otherwise. Installed a new one. I haven't messed with the connector since then. For my curiosity, i wiggled the harness again. Rough idle when I wiggled it, then smoothened out. Car never ran bad, even when it gave the restricted performance. Anyways, looking at the AFR, it isn't reading rich. MAF also seems to be reading numbers. I did buy a new OEM MAF. Thinking it was the issue.

Should I just delete the codes, and see if it comes back? Or go ahead and install the new MAF first?

 

If the wires on the backside of the MAF connector make the engine run rough momentarily, I’d say that’s your issue. I’d buy the gold plated pins (affordable on eBay), trim about an inch off the wires and use a real good crimper to join the pins to the wires. You could also use a new MAF connector repair harness and solder the wires together. It’s totally worth doing that first since you know wiggling the wires makes it run rough.

 

You might try to spray some electrical contact cleaner in the connections on both the MAFS and harness connector?
(sounds like a poor connection rather than a component fault?)
'Exercise' the connector to make better contact?

 

Exactly.

OBD tools ought to either correctly decode P1 codes or else just say

"All P1 codes are make-specific and this tool is inadequately programmed".

(As if.)

 

It has the gold pins already. But thanks!