fault code help please

[DT_]

The Cleaner,
Please do not give false information. When you challenge somebody's information or advise then please have youre facts straight. A BMW x5 3.0 does NOT have a MAP sensor. BMW's in general do not use MAP sensors. This fault is referring to the MAP coolant thermostat. I dont understand why you would feel the need to challenge me and more importantly push the thread starter in the wrong direction. I dont want to start an argument here because im only here to help and I'm here to make friends not enemies, but please with respect to you as a gentleman don't challenge my responses unless you have some basis to back up your statements. Attached is a jpeg from BMW's online system with the translation for the obd2 P-code 1620. It is the fact to back up my statement.
Cheers.

Note: file attachment is having issues http://216.93.207.213:8080/x5map.jpg

[The Cleaner]

DT, first off welcome, this is one of my favorite forums. I disagree with your diagnosis nothing more. MAP sensor or MAP temp Circuit, the terminology is not the point, the question was what’s wrong with the vehicle. I see them as related until proven otherwise, saves in part cost.

I will stand by my claim that the O2 voltage is the first thing to correct, voltage fluctuation with the manifold pressure sensor or circuit however you would like to refer to it is not IMO the cause it’s a result. If the MAP fault continues after the correction of the O2 voltage then I think MAF, MAP and TPS function should be checked (and vacuum leaks or course) . You state you need a BMW specific tool to check the O2 voltage I have been checking them will standard OBD ll Monitors/Scanners for years and standard volt meters before that.

As for P1620 code definition screenshot... I have similar reference maternal and I check it prior to each post, I know the what the text says.

ALL BMW’s use manifold absolute pressure data, we can talk about what verbage is appropriate but I’ll just stipulate the OBD ll text is correct and my terminology was less than accurate. Since BMW uses several different means to gather the data I used a general term MAP sensor to refer to the system that measures intake pressure.

I do have a question maybe you can answer, what does the DISA Valve or Adjuster unit as BMW calls it do? Part number on the unit I have for a 2.5 is 11 61 7 502 269.
Thanks

[DT_]

Cleaner,
I can see that we are going to become good friends. You are a very sharp individual. I apologize if I came on too strong but when I post information I'm always very careful to only make factual statements because I know that a lot of times people on here take what we say as the truth and they do no further research.

All of that being said I understand why there is confusion over the term "MAP" American car manufacturers and even some foreign commonly use MAP sensors. MAP standing for Manifold Absolute Pressure. BMW however does not. BMW uses the MAF (mass air flow) sensor combined with an intake temperature sensor (on this management system it is built into the MAF) along with throttle feedback potentiometers in order to come up with a "calculated" MAP-Manifold absolute pressure. There is no actual MAP sensor and therefore there can not be a Fault for that sensor.

Now the confusion lies here. BMW DOES use a MAP-controlled engine coolant thermostat. It is an electronically controlled coolant thermostat as opposed to the earlier convention style "Wax" cylinder thermostat. it has been used widely by BMW for emissions and performance purposes. In this case "MAP" is referring to the DME's (engine control module) internal MAP (mapping) which controls the thermostat. So you see in this case the terminology makes big difference.

I am going to attach what is called an I-P-O sheet which stands for inputs, processing and output. It shows every sensor input to the control module which in this case is the Siemens MS43 management system computer. It will show in a picture what im trying to explain in words.

Now that we can put that behind us please allow me to clear up the other issues as far as O2 voltage etc. I would never argue with you that checking o2 voltage is a bad thing or that it is inaccurate. I also am not trying to say that you need a bmw computer to measure O2 voltage. What I AM trying to say is that it really shouldnt be necessary. It is extremely rare to see any true voltage issues on the 02 circuit. Im not saying it isnt possible because it certainly is but it just almost never happens. What is much more common is either vacuum leaks, failed MAF's or MOST common is a dealer repgrogramming is needed because the o2 parameters are incorrect. There are at least 2 different programming bulletins posted by BMW addressing this. What I meant when I said you need a BMW fault code to know for sure is that the bulletins are listed under the BMW code not the OBD2 code.

So my personal advise to "447836......." would be to 1)check for vacuum leaks (check especially the intake air boot where the small part of the boot goes in to the throttle body, this is a very common leak on x5 3.0L)
If nothing is found then it is best to take the car to the dealer and have them run the faults and look at the BMW specific codes, compare them with any relevant service bulletins and also check the Adaptation values to get a true idea of what the management system is doing and what the MAF is inputting. As far as the MAP thermostat fault I would clear it and ignore it unless it returns in which case then the thermostat may need replacing or the circuit may need to be checked. Not everybody may agree with this but thats my advise and everyone here is entitled to give their own, including you The Cleaner.

I only hope to be helpful here Cleaner and I know that you are a veteran here and I am a NOOB but I certainly am no NOOB when it comes to BMW and BMW managemwent systems.

To the original poster please check that intake air boot, like I said its a very common failure.

http://216.93.207.213:8080/ipo.jpg

P.S The DISA valve is a electronically controlled flap in the intake manifold which changes the length of the intake runners depending on conditions in order to help with performance,emissions, and fuel economy. If you would like more technical information on it please PM me or email me and I'd be happy to send it to you.
Cheers my friend.


EDIT> also here is a portion of an actual BMW bulletin for reprogramming the O2 sensors on the MS43 management system. Im not saying this bulletin applies or will fix the problem but Im posting it so that you can see the BMW specific fault codes vs the OBD2 fault codes and why it is important to read the BMW faults.

http://216.93.207.213:8080/bulletin.doc

[The Cleaner]

Hey DT I am sure you will teach me some valuable lessons on BMW management systems. My understanding of these systems is obviously not as deep as yours. In the case of the MAP your information explains why BMW refers to the sensor I call a MAP as a Air Temp Sensor (specifically 13-62-1-738-510) on a 3.0.

I have also seen that air boot tear on a couple vehicles, mine included. I don’t like the voltage problem on that O2 sensor and seeing that TSB makes me wonder how many O2 sensors I have looked at via OBD ll scan that showed no voltage were actually OK and the software was the problem. So far a replacement sensor has corrected the problem, but I’ll be sure to bench test them in the future to be sure.

I don’t have access to a BMW GT1 Diagnostic system, sounds like you may have access . I am no expert, in fact I search out forums that will improve my skills, I expect your knowledge will be appreciated my many here.

I don’t want to hijack the thread with my DISA question, but I have seen a couple of these that make noise and I can’t figure out how to test them. I don’t think it’s an OBD monitored unit and I cant really tell if they are working.

Thanks again for the clarification and good explanation.