The users of N43/N53 already know that 3104 is probably the most famous error message.
Uneven performance of the engine in Stratified charge mode. This time – about some nuances. Quite often, people whose cars DME has recorded this error message approach me. After performing specific tests, I sometimes get an e-mail: “didn’t manage to identify the problem”. I believe that after this entry, everything should be clear.
In my blog, I have gathered basic information regarding 3104. As the error message indicates, it is strictly characteristic of a Stratified charge. The error message is recorded if DME notices (in idle or driving) increased unevenness of the crankshaft’s (Increment wheel) turning, which could mean lousy fuel burning in any cylinders or misfires. There can be many causes – starting with poor road coverage, finally with ZB (SW release – newest releases have reduced sensitivity of DME regarding the uneven turning of the flywheel, accordingly – against a recording of false error messages due to uneven road). What more is essential – for latest ZB releases of DME, when the uneven performance is detected, the Stratified charge is switched off only in the same driving conditions (torque and RPMs) in which it was identified (the segmented processing of the error message is performed).
If DME records the error message 3104, as the first one I suggest checking the misfire counters. If there are increases in any of the cylinders (or in several specific), the work should be continued with these cylinders. If the density of misfires is increased in all cylinders, check the spark plugs and ZB. Your car may have a pre-historical SW release, which is very sensitive to the slightest unevenness of the engine performance. Also, perform DIRU upgrade of your DME. The main problem arises when the owner, after the suggestion to check the misfire counters, gets in touch with me and informs me that the misfire counters are close to 0, so everything is fine! Here we have to understand that if all cylinders’ counters are 0, something has gone wrong. If all misfire counters are 0, check, for example, this link. When driving for a longer time (at least for 15 minutes), in any of the cylinders should be at least 1 event recorded.
But, if DME has recorded at least 1 misfire event, your EML 327 adapter has read it correctly; we have to assume that everything is fine with the equipment. How is that possible – there are practically no misfires (when you read them), but still, the 3104 is recorded time by time?
The first important recommendation is to note that performance problems (fuel combustion) in this specific Stratified charge mode can be pronounced only in some particular driving conditions. For example, when driving on the highway with a speed of 80 .. 100 km/h, there are misfires in some cylinders, but going in the city with a speed of 40 .. 60 km/h, everything is perfect. Not without reason, BMW AG introduced a segmented “activation” of 3104 in the newest ZB (last “portions”) DME releases. So, if DME identified the problem in some specific driving conditions, precisely on this mode, the Stratified charge is switched off for a time. In contrast, in modes with no problem, the Stratified charge continues to work. It is essential to check the freeze-frame, which contains information about precisely in which driving mode the problems started. For example:
The error message 3104 was recorded when driving evenly and accelerating with a speed of around 126 km/h. We have to drive precisely in such mode when looking for a problem!
The following important nuance – when driving in the specific driving conditions, ensure that DME uses Stratified change. It is easy to do, for example, by ../F5/F6 (Fuel mixture menu), evaluating the Lambda (in Stratified charge, it is 2.0 .. 3.5).
Or: ../F9/F1 (Injection mode menu), where the information is displayed precisely in which mode the engine is used.
Why is it so important? If DME identifies the uneven performance of the engine, it records error message 3104 and turns off the Stratified charge for some time. For older SW releases, this turning off happens for all driving conditions; for newer ones – only in the mode/segment where the problem was detected. From this moment, the engine uses the Homogenous lean injection principle (with Lambda around 1.5). If DME also detects the unevenness of the engine in this injection mode, it switches for a time to the Homogeneous injection. Yes, when starting a new driving session (restarting the engine), with a significant probability, the status of the error message 3104 will be passive, and you will be able to delete it, but DME is not a “fool”. Even if the error message is deleted, as a “precaution”, it continues to work in “lower” (Homogenous lean or even Homogenous) mode for some time and only after it restores the Stratified charge.
In addition, typically – if DME identifies uneven performance in Stratified charge, it immediately starts the individual measurement of the injectors. The engine is switched to Homogeneous mode for a moment or – every 10 .. 20 seconds switched between Homogenous and Stratified charge. During these tests, the identification of misfires could be (depending on ZB) turned off.
So – after recording the 3104, DME would have switched off the Stratified charge, and the observation of the misfire counters will not give any results!
Below I will list the most popular reasons why the Stratified charge is turned off (for a time):
a. already mentioned unevenness of the performance (which is the reason for recording the 3104 error message);
b. previously mentioned injector performance tests, when uneven performance is identified;
c. the engine has not reached the necessary (oil/coolant/exhaust) temperature – Stratified charge is turned on only when the engine has warmed up;
d. the vehicle has any problems with the NOx system (defect of the sensor, contaminated catalytic converter, etc.);
e. DME has started desulfation session of the NOx catalytic converter or is getting ready to do that;
f. DME performs any service procedures in Homogenous mode (of any hub – Lambda probes, throttle, EGR etc., or the tests of the injector performance);
g. DME has identified problems with any other system (VANOS, fuel mixture, etc.);
h. reduced performance of CO catalytic converters (even if the error messages are not yet recorded in the DME error message memory).
As we see, there are many reasons why the Stratified charge can be switched off. If we assume that the DME has no new and fundamental problems, we have to act as follows:
a. warm up the engine to the working temperature;
b. drive in the mode in which previously the problem was identified;
c. wait till DME restores the Stratified charge.
The last condition can take 5 .. 10 .. 15 minutes. Arm yourself with patience. When DME has restored the Stratified charge, continue driving for the misfires to be recorded. If the Stratified charge is turned off again, check the DME error message memory. If the error message 3104 is registered again, definitely, misfire countries should indicate the problems.
Instead, if the 3104 is not registered, turning off the Stratified charge can have any of the previously mentioned reasons: problems with any of the injectors (DME has identified inappropriate Lambda value); issues with the NOx system (the sensor or a contaminated catalytic converter); reduced performance of the CO catalytic converters; some service procedures, which should be performed in Homogenous mode. In this situation, the overall diagnostics of the engine performance will help. Initially, all possible causes of why DME turns off the Stratified charge should be eliminated; separate misfires are the last problem, which should be solved after the basic things are fixed.