crazy_88 wrote: So what steps to take? the symptom is missing, the car has been dragged along the beltway and nothing has been done.
Do the simplest things I told you about. There is probably a hole in the pipe, either
intercooler corroded (especially in the lower part) and this is the cause of air leaks. Look through the individual sections of the pipes on the channel according to the drawing, which I gave in the link to another topic. Do not worry that it's a different engine and a different pipe layout - it's about the idea - "a small hole and a big problem". I paste this drawing again.
Check the elements marked in red.
The same applies to other components that I mentioned previously, i.e.
EGR exhaust gas recirculation also the patency of the entire exhaust gas system, including the percentage
FAP clogging . Any "weakening" of these elements causes the computer to catch
sensors disturbance in type combustion
too little air or too much fuel .
Of course, there is no way "too much fuel", because as you say, the engine normally goes, so you can not find anything there. So there is "too little air" left and focus all of your diagnostic effort on it.
I emphasize with emphasis the searchlessness of searching in the most expensive and durable elements such as the control computer, etc. The error reported as a BSI fault (
U0121 communication error with the abs module, U0122 loss of communication with the vehicle dynamics module ) is some kind of garbage, or temporary, accidental recording, for example, disconnecting power during some measurements, etc. If the engine ignites perfectly, goes without problems, does not telepie and does not smoke, how can it break and repair a computer that controls the engine 100% 24 hours per day?
I think that both faults are electrically connected, because eg the mechanic has broken the cable at the ABS sensor next to the wheel while replacing the brake pads, etc. It sometimes happens that the car enters the workshop with one fault and goes with five others. You need to look carefully at the cable connections of the ABS sensors, especially when something was done on the wheels.
In turn, the message
antipollution fault (AF) It may be a consequence of the computer's "oversensitivity" in the background of disruptions in combustion, as mentioned above. The priority for him is the combustion process, which is constantly monitored by means of sensors in accordance with the procedures of EURO 5/6. Motor safety is in second place. It is only on the third people's safety. It should therefore be assumed that if the indicator lights up
AF it's a fault
MUST BE REGISTERED AS A MISTAKE IN THE COMPUTER'S MEMORY in the form of e.g.
P1234 .
Therefore, I think that in this case, a steering computer is very poorly used, which has long known what is going on in the engine, but only the mechanics can not find it. So let's devote maximum time and effort to necessarily detect what the computer means by displaying this warning indicator.
Take your diagnostic laptop to your knees and ride on the street and record as much information as possible about the combustion process on the air and exhaust side. Print them in the form of a table as below and analyze them point by point, which does not agree with the theory of combustion in a computer.
It is enough to, for example, trace while driving how it behaves
air mass (lines 12 and 12a) and
air boost pressure (13). The theoretical values (set values) must match real ones or quickly follow one another. If this is not the case, we have a clear trace of what is unfavorable and what causes it.
This applies to the other parameters, which are, as you can see, several dozen. There is no strength in doing this, you can detect the fault by using only what your own injection computer offers.
Pzdr KotBury2
