hi,Can anyone help me to figure out how best to tackle a P1226 error code on a 1998 XK8. I believe its a `control sleeve sensor malfunction` which i got from this site, but still dont know where to start.paul

 

Wow! that is a new one.

The Mechanical Guard Sensor is associated with the Throttle body. I found the test charts in JTIS section 303-14 through a global search.

On initial review, it seems only applicable to early engines. The P1626 code is not even in the AJ27 charts. Let us know how it goes so we can all learn something.

 

I am unable to locate the P1226 or P1626 for Jaguar; however, I found a little info on the internet. It not being Jaguar specific my evaluation may not be correct but I believe it is related to the throttle body. The first thing I would check is if the throttle body recall applies to your car. The second if that did not apply I would look into the connectors at the throttle body. Clean them and reinstall or replace. Both have been a problem with early model year and you should look into it even if it does not apply to this problem. TSB 303-58 for the connectors and not knowing the year or vin of your car you will need to check with Jaguar to see if the throttle body recall applies. I know that you were addressing the Throttle body replacement in an earlier post, have you had this done yet?

 

i checked out the recall but it had been carried out 2004 (although that also looks like it has been "changed" along with my ECU whilst in the salvage yard). i noticed the error code 1226 in the FAQ threads for restricted performance issues,that you guys had put together ( a really good idea by the way) and it was highlighted differently to all the others...does this mean anything? i have a spare throttle body and will give it a try. i will keep you posted.

 

The test sequence consists of checking the wiring, power, continuity and resistance to ground between the ECM and the sensor. It is powered by a 5v supply out of the ECM. The last entry says to replace the sensor so it might be a part short of the entire TB.

Send me a PM with your direct email address and I will return the JTIS test procedure.

Gus's TB connector thought may be the issue.

 

hi, if u can send it to thebuttman@hotmail.com i would appreciate it.

cheers m8.

 

In my OBDII code list for Jaguar, the P1226 code states: Mechanical guard circuit range/performance. I have no idea what that means!!

 

hello everyone, thanks for your help with this p1226 error. just to let everyone know and in case it helps anyone, i resolved this by clamping off a black breather hose that comes out of the top of a black "cap" at the top of the throttle body. i cant explain why it worked but it came from a Jag owner who had experienced the same.

 

That's a quick fix, and it works for awhile. Replace the throttle body...the actuator spring becomes weak over time and the ecm can not maintain or control position. When you clamp off the breather it cause a small vacuum chamber behind the spring which acts like a stiffer spring(so to speak). The actuator will eventually fail though.

 

i tried that first with no effect. The error code wouldnt reset hence this thread. If you know any other long term fix i would be grateful.
paul

 

This thread is the reason I joined the Jaguar Forum. I recently bought a 1997 XK8 on eBay on a total whim. It was cheap, I absolutely love the car so I am not really stressing. And I think just about everything on it is manageable. However, I also retrieved the P1226 code. From reading this thread and particularly Mr. Smith's comments it appears that he received a lot of good advice but each time came up empty. I also noticed one reply that said it applied to "older" engines. Does that include 1997, or was something older intended? The last thing, it appears that he was told to replace the throttle body and still got the code. Has there been any further information generated on this subject? I will be entrusting this car to a mechanic and hope he can sort it out, but this is troubling because P1226 is apparently not even recognized by Jaguar. I downloaded the workshop manual. It is not listed. So, I don't know how the mechanic is going to solve it, and I am wary of getting into the mode of replacing expensive parts until something finally works.

 

This P1226 is listed on Jaguars trouble codes http://www.jagrepair.com/images/Auto...%201997-99.pdf From what I understand it is internal to the TB where the actuator pedal is connected to it. I can only suggest that you have it rebuilt much cheaper that a new replacement. I have used ASI with positive results the link is below.

Link Welcome To Auto ECU Inc.

 

I am the owner of a XK8 1997 . Recently I got the message: Restriced Performance. My OBD readings indicate Codes P1226 and P1227. What should I do to repair this???

 

Follow the advice posted above, and check & clean the electrical connectors & associated wiring to the throttle body.

I've attached the '303-14 Electronic Engine Controls' section from JTIS which contains pinpoint tests for the two codes you have found.
I don't think the 'mechanical guard sensor' is available as a separate part.

Note that the links don't work in the pdf, although you should be able to find the associated headings.

You will need the '97 Electrical Guide for reference to the connectors, etc. It's available from Gus' site of everything here:
http://www.jagrepair.com/images/Auto.../jagxk1997.pdf

It could also be an ECM problem as the 97 module is prone to leaking capacitors, so I'd suggest pulling it and doing an inspection before spending any $$$ if the pinpoints don't reveal the issue.

Run the checks, report back and good luck!