I have had the exact same problem...Check engine light comes on...then restricted performance...temp gauge pegs out...Shut off engine....Engine temp gauge normal..restricted performance goes away..check engine light stays on...This only happens when highway driving...Could happen again in 4 to 5 miles or it could be 150 to 200 miles..codes are temp sensor (just replaced with NAPA replacement part) and themostat (replaced also) 2005 VP 73,000 miles...Now what?....Thanks

 

Hi JtRuth,

Have you had your car scanned for the stored Diagnostic Trouble Code(s) (DTCs)? It is possible your problem is the same as the one described in this thread, or you may have a different root cause with similar symptoms. Without the stored codes, you are guessing at the cause.

Most auto parts stores will scan the generic OBDII codes for free, but for the Jaguar-specific codes you will either need to visit a Jag dealer or good independent Jag mechanic, or make a small investment in one of the Mongoose cable/SDD software kits that many of us are using with a laptop computer to gain dealer-level access to the many systems and modules in our X350s.

Without knowing what codes were tripped when the CEL illuminated, you're guessing, and guessing can get expensive quickly. Having the codes scanned is a small expense compared to the money that can be wasted on unnecessary parts.

Cheers,

Don

 

I did check the codes and they were 116 and 128

 

I read the codes with a Actron cp9550 pocketscan plus tool. Not the best that money can buy but it works well enough so that I know what I might be dealing with. Did Jag ever have a service bulletin out on this problem? I understand that this is not an uncommon problem......Thanks

 

Just for fun you wouldn't know the service bulletin date and number, would you? Thanks

 

Hi JtRuth,

Generic OBDII codes are preceded by a letter and then have four digits. Were your codes P0116 and P0128? If so, you can look up their definitions in the Powertrain section of the X350 Workshop Manual, which you can download in six sections from the links below:

http://www.mediafire.com/download/md...f+contents.pdf
http://www.mediafire.com/download/aa...nformation.pdf
http://www.mediafire.com/download/n3...2.+Chassis.pdf
http://www.mediafire.com/download/9b...Powertrain.pdf
http://www.mediafire.com/download/0i...Electrical.pdf
http://www.mediafire.com/download/4j...+and+Paint.pdf


Use the Search function in Adobe Acrobat Reader to search for your codes (while holding the Cmd or Cntrl key, press the letter F key and a search window will appear).

The manual will either give you suspected components or systems in the table of Diagnostic Trouble Codes (DTCs), or it will refer you to a section of the manual that deals with the relevant component/system.

Both the P0116 and P0128 codes indicate a problem with the Engine Coolant Temperature sensor (ECT), the coolant thermostat, contaminated coolant, low coolant, the ECT wiring harness, and other possible causes. The P0116 code is associated with the ECT and prompts the Restricted Performance. Since you've replaced both the ECT and thermostat with presumably good new units, you may have a problem with the wiring harness for the ECT. Start with the electrical connector and inspect for corrosion or damage to the terminals or wiring (worn or burned insulation, broken conductor, etc.).

If you have an ohmmeter (Digital Multimeter, VOM, etc.), it might be worth comparing the DC resistance readings of your old ECT and the new one from NAPA with both at the same temperature. If both read the same or close, that may further indicate that the issue is not the ECT but in the wiring between the ECT and ECM.

As I mentioned, a standard scanner like your Actron can only read the generic OBDII codes. It can't read the proprietary Jaguar codes, which may provide additional helpful diagnostic info. For example, your car may have one or more "U" codes stored, indicating network communications issues, that might help pinpoint the problem.

Regarding a TSB, members have uploaded a lot of them to this forum, so it might be worth looking through the ones in the X350 'HOW TO' quick links/Download Library:

http://www.mediafire.com/?x11yhijup29yt#8viyccmusy9t1

And also the ones in the JagRepair.com library:

JagRepair.com - Jaguar Repair Information Resource


Please keep us informed!

Cheers,

Don

 

Thanks so much for the info...Will advise as to the progress to resolve this issue..Jags, the love hate relationship goes on..

 

[QUOTE=JtRuth;1128227]Thanks so much for the info...Will advise as to the progress to resolve this issue..Jags, the love hate relationship goes on. New thermostat installed today Jan.6th 2015. We shall see what happens

 

So here was the real fix. replace the thermostat and the plastic housing with it. Seems that after awhile the plastic starts to crack internally so the water temp is not right followed by the computer going nuts. Anyway the problem has not returned