AEM 30-3510 Infinity Plug & Play Harnesses - BMW 2001-2006 E46 M3 - Manual (Page 8)

8
© 2014 AEM Performance Electronics
P/N 30-3510
DRIVE-BY-WIRE THROTTLE CONTROL
The BMW M3 S54 engine uses 6 individual throttle
bodies controlled via drive-by-wire (DBW). It is important
to note that throttle control is a critical system which
needs to be correct, and the BMW E46 throttle and
intake system is a unique implementation with several
details that require careful attention. The basic terms of
drive-by-wire are as follows: the ‘gas pedal’ inside the
passenger cabin is called the Accelerator Pedal
(DBW_APP1%), while the electronically controlled
throttles in the engine bay are referenced as ‘Throttle’ (Throttle%, DBW1_TPSA%). Based on the
measured Accelerator Pedal position, the ECU determines a desired DBW_Target position and moves
the Throttle to that position.
As shown, there is a
Drive By Wire Wizard
which must be used to
calibrate accelerator
pedal and throttle
position sensors.
Although sensor
calibration values from
one vehicle may be
close enough to work
for another vehicle
under some circumstances, it is absolutely necessary to run the Drive By Wire Wizard before running
the engine for the first time. The wizard should be repeated if any components in the throttle control
system are removed or replaced such as the throttle bodies, TPS sensors, throttle linkage, electronic
throttle control motor, or accelerator pedal.
Please ensure the vehicle’s battery is fully charged (at least 12.5 Volts) before running the Drive By Wire
Wizard, as low battery voltage can result in abnormal sensor measurements. If a battery charger is
available, it is preferable to connect the battery charger in 5A, 10A, or 20A mode and perform the Drive
By Wire Wizard while the battery voltage is near 13.5
– 14.0 Volts. When connected to the Infinity EMS
with the engine OFF, go to Plug-in | Wizards | Drive By Wire Wizard. On the first page, be sure to check
the ‘Calibrate Sensor Data Only’ checkbox before selecting ‘Start’. Follow the step-by-step instructions
for each page.
The BMW E46 M3 SPORT button located in the center
console (shown) still serves as a switch input to the
ECU. Contrary to some misinformed beliefs, this button
never changed the maximum power output of the
engine. This switch changes the accelerator-pedal to
throttle-target relationship in the stock BMW DME.
These curves are configurable in the Infinity Tuner
software using the DBW_ThrottleCurve1 /
DBW_ThrottleCurve2 tables, which allow the tuner to define the DBW throttle target based on
Accelerator Pedal Position and Engine Speed.