7
Introduction
4 Introduction
The WABCO iABS Automatic Lift Axle Control system uses the generic I/O capability to automatically
control the lift axle function of the trailer. The Lift Axle function may be configured in three different ways.
Each method has its own specific hardware requirement and installation.
Automatic Override Kit 400 612 039 0 is a fully automatic system that uses a combination of switch input
and lifting and lowering pressures all preset by the trailer manufacturer using the WABCO TOOLBOX
PLUS™ Software. This lift axle configuration monitors axle load in order to raise or lower the lift axle
without driver intervention. The system senses the load and raises or lowers the lift axle based on preset
suspension air pressures set by the trailer manufacturer. When the lift axle control valve is activated and
raises the axle, an optional lift axle indicator on the trailer is activated to signal to the driver that the lift axle
is in the “raised” position.
Kit 400 612 039 0 contains hardware for a fully automatic feature that will keep the lift axle in the lowered
position when the parking (spring) brakes are applied. When the parking (spring) brakes are released the
lift axle will move to the load appropriate position.
Manual Override Kit 400 612 040 0 is a fully automatic system that uses a combination of switch input and
lifting and lowering pressures all preset by the trailer manufacturer using the WABCO TOOLBOX PLUS™
Software. This lift axle configuration monitors axle load in order to raise or lower the lift axle without driver
intervention. The system senses the load and raises or lowers the lift axle based on preset suspension air
pressures set by the trailer manufacturer. When the lift axle control valve is activated and raises the axle,
an optional lift axle indicator on the trailer is activated to signal to the driver that the lift axle is in the “raised”
position.
Manual Override Kit 400 612 040 0 contains the required cables for a manual override switch option that
can be activated to keep the lift axle in the lowered position regardless of vehicle load. Please refer to local
governing ordinances.
Automatic/Manual Override Kit 400 612 041 0 is a lift axle system that features both automatic and
manual override modes.
This lift axle configuration monitors axle load in order to raise or lower the lift axle without driver
intervention. The system senses the load and raises or lowers the lift axle based on preset suspension air
pressures set by the trailer manufacturer. When the lift axle control valve is activated and raises the axle,
an optional lift axle indicator on the trailer is activated to signal to the driver that the lift axle is in the “raised”
position.
This kit contains hardware for a fully automatic feature that will keep the lift axle in the lowered position
when the parking (spring) brakes are applied. When the parking (spring) brakes are released the lift axle
will move to the load appropriate position.
This kit also contains the required cables for a manual override switch option that can be activated to keep
the lift axle in the lowered position regardless of vehicle load. Please refer to local governing ordinances.
Note 400 612 039 0, 400 612 040 0 and 400 612 041 0 must be used with a WABCO iABS
Premium ECU/Valve assembly 400 500 350 (2S/1M) or 400 500 430 0 (2S/2M - 4S/2M).
Refer to the instructions in this technical bulletin for installing the WABCO Trailer iABS with Lift Axle Control
Option.
4.1 Configuration of Lift Axles by Functionality
The Lift Axle function may be configured in three different ways.
