1 Series E81 118i (N46T) 3-door
The purpose of air injection via the secondary air system is to carry out exhaust re-treatment during the engine
warm-up phase.
-
Radiator fan
The radiator fan is controlled by the DME control unit via a pulse-width-modulated signal (evaluation by
electronic circuitry in the fan).
The DME control unit controls the various radiator fan speeds by means of a pulse-width-modulated signal
(between 10 and 90 %). Cycle ratios which are less than 5 % and greater than 95 % will not trigger the
control device and are used for the purposes of fault recognition. The speed of the radiator fan is dependent on
the coolant temperature at the radiator outlet (radiator) and the pressure in the air-conditioning system. When
the car's road speed increases, the speed of the radiator fan decreases.
-
A/C compressor
> E46, E83
The A/C compressor relay switches the A/C compressor on or off. The A/C compressor relay is controlled by the
DME control unit. The IHKA control unit sends the actuation prompt via a CAN message.
> E85
The DME control unit is connected to the integrated automatic heating/air-conditioning system (IHKA). The IHKA
control panel/control unit switches the A/C compressor on or off.
> E81, E87, E90, E91, E92, E93
The DME control unit supplies the signal to the junction box electronics on the PT-CAN (Electrical System 2000).
The junction box electronics switches the A/C compressor on or off. The IHKA control panel/control unit prompts
the actuation.
> E60
The DME control unit supplies the signal to the IHKA control panel/control unit on the CAN data wire. The IHKA
control panel/control unit switches the A/C compressor on or off.
-
Suction-jet pump
> N45/N45TU2 only
A suction-jet pump generates the low pressure required by the brake booster. The suction-jet pump influences
idling-speed control through its air requirement. For this reason, the
suction-jet pump is activated or deactivated by a solenoid valve controlled by the DME.
[For further information, please refer to SI Technology (SBT) 11 02 05 130]
-
Electric vacuum pump
Spark-ignition engines with low vacuum in the inlet pipe also have a vacuum pump that generates additional
vacuum. The vacuum is primarily used to boost the brake force.
[For further information, please refer to SI Technology (SBT) 11 02 05 130]
-
Variable engine bearing
> Only N46TU2 in the E60 (N46B20OL for national version RoW = Rest of World)
The DME switches the switchover valve for the engine bearing. The actuated switchover valve opens, releasing
the vacuum to the engine bearings.
System functions
The following system functions are described:
-
Power supply and voltage monitoring
-
Electronic immobiliser
-
Air supply: differential air intake control "DISA"
SBT Engine control for N45, N46 E46, E60, E81, E83, E85, E87, E90, E91, E92, E93
BMW AG - TIS
19.01.2013 06:10
Issue status (12/2007) Valid only until next DVD is issued
Copyright
Page - 8 -
