I have a 2004 Jaguar XKR and this is the 2nd time in 2k miles my car went into Restricted Performance Mode (RP Mode) due to the Mass Air Flow Sensor (MAF Sensor). The 1st time I shut the engine off for 15-20 minutes, the computer system reset, and I was good to go. This will not happen all the time. This time I drove it home in RP Mode. You can drive in RP Mode, but need to shift manually to keep the revs up and don’t try to pass anyone. After I got home I put an OBD Meter on it about 30 minutes later and the ECU already reset. Both times the OBD meter showed a text stating “Mass Air Flow Sensor - High Voltage”. With the 2nd incident, about ten miles before going into RP Mode, the engine started pinging. A faulty MAF Sensor can cause pinging by not telling your ECU to adjust engine timing.

The 1st time I sprayed a MAF Sensor cleaner on the wire. It didn’t look dirty at all, but sprayed it anyway. This time I decided to buy a new one. The existing MAF Sensor is by Denso, but when I went on the Denso website they do not make one for my Jaguar or an XK8. This could be the issue. So I ordered a new MAF Sensor by Delphi through Rock Auto. I have not received it yet. The existing MAF Sensor is glued in place and not screwed into place (strange). Hopefully this will resolve the MAF Sensor issue.

 

What was the actual code?

This might show for example that you have a short circuit and the MAF is fine.

 

The code was P1111, which means all systems go. I would think a short would be a continuous issue and not cause an issue every several thousand miles. I am hoping since Denso doesn’t make a MAF for this car that it gives readings that aren’t totally accurate. Your thoughts.

 

Remember, this sensor is actually packaged an an air flow meter and an air temp sensor. The air temp sensor is hanging as a "bulb" on the side. The actual air flow meter is much deeper into the recess. Folks have indicated that the cleaning has to be fairly intense, including keeping the sensor upside down for a bit to let the solvent do the cleaning. This is not a quick spray and reinstall.

Also, be sure to check the quality of the o-ring around the base. It seem to interfere a lot more than expected if it is pinched, old or somehow missing.

As usual, check the long term fuel trims for clues, especially if it is pinging. The codes only trigger at 25%, but nothing good comes from trims above, say, 5%

For the Denso sensors, you may have to do more research. I have definitely bought a Denso sensor for my XK8. Check ebay, these sensors are typically compatible with many different cars.

 

That's not a fault code - it's a (good) status code. You want it to have that.

(If interested, you can read up about it in the various posts & Jaguar docs on here and on JagRepair.com - Jaguar Repair Information Resource)

You seemed to be saying you had an actual fault - if so, what was the code?

 

There was no other code. The car went into Restricted Performance Mode. I drove it home in RP Mode, turned off the engine, connected the OBD meter about thirty minutes later and all I got was P1111 and a text on the MAF. No other codes found. I know there are OBD meter made for Jaguar alone and they go into sub-catagory codes, but I have a regular universal OBD meter.

 

What do you mean "a text on the MAF"?

P1111 is not an error. If your tool said it's an error, the tool is just misleading you so ignore it.

P1111 is never the cause of RP (Restricted Performance).

Sadly that may leave you looking for what the actual cause is, with no information so far to help.

 

The OBD showed P1111 and under it was wordage stating “High Voltage indicated - MAF”.

 

Your tool is wrong. That is not what P1111 is.

 

Ok, thank you!

 

I know P1111 has nothing to do with the message regarding the MAF. What P1111 is telling me is that it has reset itself. The MAF message also shows on the meter, but has nothing to do with P1111. If I had the meter plugged in before the system reset itself, I would have also received a code regarding the MAF.

 

I also looked for a Denso replacement for my 2006 XK8 but could not find a listing even though my unit is a Denso and appears to be original. An email to Denso's customer service folks generated a response indicating that they do not offer a unit directly unless authorized by the manufacturer. In our case, Jaguar wants to continue selling MAF's through their dealer parts departments. My guess is that it is not unique to the XK8. Has anyone broken this code and found it listed for another vehicle?

 

P1111 also does not mean that it has reset itself (what now?).

You can, and normally would, have P1111 as well as codes.

If you reset the codes, the P1111 instantly changes to P1000 - because a clear means "clear codes and status of OBD monitors" (i.e. both are cleared, by law).

So... back to asking: what was the code other than P1111 (which is a pending code only and never turns into a code) that you had?

Or... has there just never been an actual code? It's going to be tough to do much diagnosis with no code.

 

My experience is that these machines can be initially "shocked" by/when sensing a "new" reading that varies from what it's become familiar with. The MAF provides integral electronic information to the ECU... Hmm, knowing me, if I was having trouble after introducing or replacing a part like the MAF, I would do a hard reset. Have a beer (if I drank, lol) and do some other things for an hour or so while having the POS and NEG terminal cables pinned together/touching,,, or even do a hard reset touching the NEG to the positive terminal (which always gives me the freakouts) and then let the machine "relearn" things with the new components??? Couldn't hurt, right?

Also, I think that there IS an alternative MAF made by Denso (much cheaper) BUT made for the Subaru Forester or Outback... But, silly me, I have NOT been able to dig deeply enough to figure out what the part number is for that alternative... Not to hijack the thread,,, BUT,,, does anyone have that information? The alternative MAF?

Hope that helps some. Sorry it's happening. I know it's frustrating.

 

Replace the sensor, maybe...? I found this.

https://rover.ebay.com/rover/0/0/0?m...2F283330962373

Then, in the forum "interchangeable" sticky I found. This forum is amazing!

""""This is a list of cars that use the same mass air sensor:

2000-2003 Jaguar Vanden Plas Exc. Supercharger
1999 Jaguar Vanden Plas
1999-2003 Jaguar XJ8
1999-2002 Jaguar XK8
2010 Mazda 3 2.3 Liters
2007-2009 Mazda 3 Turbo
2006 Mazda 6 Turbo
2010 Mazda CX-7 2.3 Liters
2007-2009 Mazda CX-7
2007 Mazda CX-9
2005-2006 Saab 9-2X
2004-2007 Subaru Impreza
2002-2003 Subaru Impreza 2.0 Liters
2008-2009 Subaru Legacy 2.5 Liters Turbo
2008-2009 Subaru Legacy 3.0 Liters
2004-2007 Subaru Legacy
2008-2009 Subaru Outback 2.5 Liters Turbo
2008-2009 Subaru Outback 3.0 Liters
2004-2007 Subaru Outback
2006-2007 Subaru B9 Tribeca
2004-2006 Subaru Baja Turbo
2004-2010 Subaru Forester
2008-2010 Subaru Tribeca

 

There were no other codes.