The impact of alterations in control unit software on the BMW 3.0D engine power and torque

At present, there are different methods to increase the performance of compression-ignition engine with Common Rail fuel supply system. One of them is to use external modules of the Tuning Box type. These modules are the simplest and cheapest solution to increase power and torque and reduce fuel consumption. Another method is to re-programme original bitmaps in control unit memory. The charge storage is read from engine controller memory via a diagnostic connector to EDC16 engine control units or by mechanical intervention into the driver itself. It is a labour-intensive method, which involves removing the driver from a vehicle, dismantling the cover, unsoldering the memory chips, reading the data programmer and re-programming the memory chip. This method is used for vehicles equipped with EDC15 engine control units. The paper presents a modification of the control unit software of BMW E39 530D vehicle which increases its torque at low and medium engine rotational speed range by eliminating the so-called “turbo lag” and improves vehicle driving dynamics. Reading was done with EEPROM programmer device and software via an EOBD diagnostic connector; fuel injection, EGR valve, boost pressure and smoke limiter bitmaps were modified and the memory was re-programmed.