Hi Guys,
Our Jeep Cherokee keeps going in to limp home mode, cheap code reader shows P0069 fault.
I had removed and cleaned the MAP sensor a few months back and it was really covered in crud but I had done this by chance and it wasn't showing any codes back then.
Yesterday the fault started, on reading the fault code I removed it again, clean as a whistle, 117kPA reading too at idle but to be honest I don't know what it should read..
Turn ignition off and back on and it runs fine for a while..
So, do I go ahead and install a new MAP sensor or look for some other cause.. 
Thanks in advance..
db.
Have you checked this ? Loads of good advices for the KJ CRD owners.
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=54207&sid=e3d589e6507fb20d1c8bf3b1c506501f
I very much agree with checking out this thread on LOSTJEEPS.com. The Noob Guide is the first place any CRD owner should visit.
However, one of the things that even the Noob Guide does not discuss enough is just how critical maintaining proper engine temperatures in modern diesel engines is. The O.E. thermostat assembly in the V.M. Motori R425 and R428 engines is terrible, and is a poster child of all the things that are wrong with proprietary technology.
The manufacturers deliberately make these more complicated than they need to be, so that the aftermarket will not try to copy the design. The CRD owner, therefore, has to go to the dealer to purchase these at inflated prices. Unfortunately, the quality of the O.E. part is suspect... at least here in North America the O.E. thermostat assembly lasts only about 50,000 miles, when traditionally thermostat valves would need to be changed out perhaps twice in an engine's lifetime.
It gets worse for the O.E. thermostat... it is not even designed to open up at an optimum temperature for a diesel engine. The factory service manual for the Jeep Liberty, (Cherokee for you folks), CRD states that the opening temperature for the O.E. thermostat is 176 degrees Fahrenheit. You ask ANY diesel technician and they will tell you that is too low for a modern diesel engine, especially one that has pollution control systems on them. You folks in the U.K. having problems with clogged out cylinder heads, gunked up turbochargers, clogged up MAP sensors and related problems, just like we have here in North America? You can blame a lot of that on the fact that the O.E. thermostat, even when new, was running the engine too cool. Modern diesel engines need to run HOT in order to take full advantage of all of the efficiency, reliability and power that they can provide.
There is now a viable alternative to this problem. I manufacture a direct aftermarket replacement for the O.E. thermostat assembly. My unit, the Hot Diesel Solutions Model 001 engine thermostat assembly, is far superior to the O.E. thermostat for the following reasons...1) It is a superior design. The Model 001 has a removable cap that allows the owner to replace just the thermostat valve itself, instead of the whole unit. The Model 001 uses the same thermostat valves that are in the Chrysler Hemi V-8 series of petrol engines, and will be readily available for years to come. The Hemi thermostat valves are available in at least 3 hotter opening temperatures than is offered by the O.E. part, and are far larger than the O.E. valve to allow for better flow when driving conditions demand maximum performance from the cooling system.
2) It is way better quality. The Model 001s main housing, cap, and hose barbs are CNC machined from solid blocks of 6061 aluminum. This unit would probably pass testing to be used in an aircraft, it is so solidly built.
3) The Model 001 has machined into the housings extra threaded ports, (they are plugged when the Model 001 is shipped to the customer), for easy installation of aftermarket temperature sending units. This facilitates easy installation of an accurate engine temperature gauge, and for a conversion to an electric cooling fan.
The following is a link to the thread I started for the H.D.S. Model 001 on LOSTJEEPS.com. Customers have left feedback on the Model 001 starting on page 12, and again on page 25. I have already sold about 80 Model 001s, and all of my customers are very happy with the quality and performance of their thermostat assemblies...
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=169&t=75791 
