Air conditioning/cooling fans

AIR CONDITIONING/COOLING FANS

Air Conditioning (if fitted) / Fan Control

On all models, an electric cooling fan is fitted in a housing at the right hand end of the radiator. Models fitted with air conditioning have an additional condensor fan fitted in the housing on the left hand side of the radiator.

The ECM controls the air conditioning grant output. If an input is received from the air conditioning select button, with the interior blower fan on and the trinary switch set, the ECM will consider engaging the air conditioning clutch. The ECM considers the coolant temperature and the throttle position before the air conditioning grant is operated. When the air conditioning grant is started, the cooling fans operate in slow mode, unless the coolant temperature is above a set value when they operate in fast mode.

The ECM provides two outputs to control the two cooling fans; slow mode and fast mode. The modes of operation vary depending on signals received from the air conditioning thermostat, the ECT sensor and the ECM. In slow mode, both fans operate in series sharing the same electrical feed. In fast mode, both fans operate in parallel, each fan receiving its electrical feed from a separate source.

Cooling Fan (Vehicles without air conditioning)

The ECM controls the operation of the cooling fan. The ECT sensor constantly sends signals to the ECM. When engine coolant reaches 106°C, the ECM switches the cooling fan on, in fast mode, until the engine coolant temperature is reduced to 100°C or less.

When the ignition is turned off, the fan can continue to operate for up to eight minutes if the ECT sensor senses a coolant temperature of 114°C or above. The fan will turn off when the temperature decreases to 112°C or less or when eight minutes has elapsed. If a temperature of 114°C is not sensed within five minutes of ignition off, the fan will not operate.

Cooling Fans (Vehicles with air conditioning)

The ECM controls the operation of the cooling and the condensor fan. The ECT sensor constantly sends signal to the ECM. When engine coolant reaches 112°C, the ECM switches the cooling and condensor fans on, in fast mode, until the engine coolant temperature is reduced to 100°C. The cooling fans will operate at slow speed when A/C is operating unless overriden by a high temperature, fast speed request.

When the ignition is turned off, the fans can continue to operate for up to eight minutes if the ECT sensor senses a coolant temperature of 114°C or above. The fans will turn off when the temperature decreases to 112°C, or less, or when eight minutes has elapsed. If a temperature of 114°C is not sensed within five minutes after ignition off, the fans will not operate.

HILL DESCENT CONTROL (HDC) SIGNAL (Vehicles with ABS Only)

The ECM constantly monitors signal information for throttle position and engine speed and also assesses other engine inputs to produce an engine torque signal. These signals, along with engine and gearbox identifiers, are passed to the ABS ECU to control hill descent.

See BRAKES, Information.

The ECM constantly monitors signal information for throttle position and engine speed and also assesses other engine inputs to produce an engine torque signal. These signals, along with engine and gearbox identifiers, are passed to the ABS ECU to control hill descent.