The N54 engine is conceptually similar to N53; their main differences are:
a. N54 does not use Stratified charge;
b. to increase the torque/power, N54 is equipped with two turbochargers that work in a pulse mode.
To solve problems with the wide distribution of parameters of piezo injectors: in short openings (because of which in the case of N43/N53 series, a range of precise measurements are made in Stratified charge mode and these measurements are not available for N54), Rail pressure in idle and in low torque conditions is reduced to 50 Bar (the max pressure is left the same as for N43/N53: 200 Bar).
Turbochargers are with electrically manageable parameters, which reduces reaction time and improves the engine’s response in case of swiftly increasing required torque.
Exactly the electrically manageable turbochargers are the reason why these engines arouse interest between chip tuners.
I’ll add right away – I haven’t seen not even ONE successful case of chip-up for these DME.
All chip-up cases, which I have seen, have common problems:
a. the error messages regarding Boost pressure, which throws DME in a complete limp mode;
DME does not measure the injectors and does not perform the optimization of the cylinder performance, does not performs adaptations (not even within the banks), as a result:
b. Offset type LTFT of the banks are not confirmed;
c. Multiplicative type LTFT of the banks are not upgraded correctly;
d. very often, the integrators are significantly different from 0 because the adaptation maps of the banks are not upgraded;
e. both – in idle and on the go, the mechanical efficiency of cylinders is incorrect because the injectors are not measured, and the individual fuel mixture of the cylinders is very incorrect;
f. a range of other problems – the wideband probes are not trimmed, the performance tests of the CO catalytic converters are not performed (for this reason, the error message regarding their performance does not appear at all even in cases when it is not possible to pas the TI, because the catalytic converters are completely damaged), etc.
The consequences of such “upgrades” – overloaded and prematurely damaged CO catalytic converters; symptoms – permanent vibration; unsolvable misfires; shivering of the engines.
Instead of the expected increase of the power – typically: 0 gain. In the near or distant future – damage of the CO catalytic converters and/or turbochargers.
Quite often, these engines’ owners approach me because their neverending fight with vibrations and misfires does not give any result. Not even the replacement of ignition coils, spark plugs, or even injectors don’t help. Additionally, these engines do not have the Valvetronic, which (in the case of HVA problems) could in some negative impact on the air distribution in cylinders.
I will not burden you with INPA screenshots, in which the incorrect fuel mixture, high integrator values, unconfirmed Offset type adaptations, incorrect mechanical efficiency of cylinders can be seen. This time I will put an accent to the next stage.
Next stage, when the cause of the problem – incorrectly performed software changes – has been understood, the owners of these vehicles want to restore the stock software. Usually, after a day or two, I get good news – the stock software is restored! We can move on! Yes, the error messages regarding boost pressure usually have disappeared, but…
Unfortunately, only in some of the many cases, this statement is true. Here, an example, how the “stock” DME live data looks in ISTA+ after “restoring.”
As you see, the ISTA+ has identified the cars equipped with N54, but the configuration of DME itself is misread or is not read at all! ISTA indicates a range of parameters, which does not apply to N54: performance mode (N54 works only in Homogeneous mode), the data of NOx sensor and NOx catalytic converter appear (logically, there are error messages regarding them because the N54 does not have these systems at all). Instead, the parameters specific to N54 can not be found at all!
And yes, in the second image – the Offset type LTFT are still not confirmed, readings of the control probes – incorrect (obviously, the wideband probes are not trimmed correctly – one more of the side-effects of such software “improvement”.
Why does such a situation happen?
Unfortunately, for 10 years old cares, all modules are rarely without the error messages; the configuration – as from the factory. If there are any error messages in the modules or changes of configurations – it is not possible to use ISTA P. Accordingly – the programming and encoding of the DME are not possible in the “automatic” mode. WinKFP and NCS software should be used, but it requires much more serious knowledge. Unfortunately, this serious knowledge is not very common. Typically, the “circle” starts – the owner of the car turns to the chip tuners, they as if restore the stock software. The diagnostic equipment and live data prove exactly the opposite. Then comes the next try to restore, and so again and again – either till more or less successful result without any warranty regarding it, or – the car owner gives up. Unfortunately, the second scenario is prevalent.
I urge you not to modify the software of the DME! None of the chip tuning, which I have seen, does modify (also) the formulas of the energetical model (their coefficients), which means – the error messages regarding the performance of the hubs, the complete limp mode is guaranteed! And as a bonus, large problems when trying to restore the engine’s initial (correct) performance are guaranteed!