Range Rover P38
70
BRAKES
NEW RANGE ROVER
12
DESCRIPTION AND OPERATION
ABS Electronic Control Unit - ECU
ABS/ETC operation is controlled by the ECU. The
ECU is attached to a bracket which in turn is attached
to the bulkhead. A closing plate beneath the
passenger side fascia provides access to the ECU.
The ECU is connected to the ABS harness by a 35 pin
connector on up to 99MY vehicles and by 9, 15 and
18 pin connectors on vehicles from 99MY.
When system faults are detected by the ECU, warning
lamps in the instrument pack can be illuminated for
ABS, ETC and braking system faults. Certain faults
are also displayed in the instrument pack message
centre. Refer to Operation - Warning lamps for lamp
and message centre operation.
The ABS ECU generates a digital road speed signal
from the average speed of the four wheels. The ABS
ECU passes the road speed signal to the BeCM. The
BeCM outputs the road speed signal to the following
interfaces:
•
Engine Control Module (ECM)
•
Cruise control ECU (V8 only)
•
Instrument pack
•
Air Temperature Control (ATC) ECU
•
In-Car Entertainment (ICE)
•
Electronic Air Suspension (EAS) ECU
•
Electronic Automatic Transmission (EAT) ECU.
The ABS ECU also outputs a rough road signal to the
ECM on V8 engine vehicles only. The digital rough
road signal is generated from the difference in
rotational speed of each wheel.
The ECU is a non-serviceable item, it must be
replaced if failure occurs.
