
DESCRIPTION AND OPERATION
4.60 RANGE ROVER
Cooling Fan
Operation of the cooling fan is controlled by the ECM. When the compressor is engaged, the
ATC ECU (C1629) informs the ECM (C0331) via the K bus on a WRY wire that cooling fan
operation is required. The ATC ECU also informs the ECM of the speed at which the fan
should be driven.
The ECM also monitors Engine Coolant Temperature (ECT) to determine fan speed. The
ECM (C0606) provides a feed to the ECT sensor (C0169) on an SU (Td6) or YG (V8) wire.
The ECT sensor is a Negative Temperature Coefficient (NTC) sensor. By measuring the
voltage returned on an NG (Td6) or NO (V8) wire, the ECM can determine engine coolant
temperature.
The ECM (C0331) now provides a feed to the cooling fan control unit (C0005) on a BG wire.
This is used by the control unit to regulate the supply voltage from maxi fuse 61 of the
passenger compartment fuse box (C0581) on an RU wire.
No