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Keith · 7th December 2006, 13:59

OPERATION

K1.8
General
Feed from the positive battery terminal (CO192) is supplied to fusible link 4 and the main relay (C0632) on an R wire. Both are located within the engine compartment fuse box. Fusible link 4 (CO574) supplies a constant battery feed to the low and high speed relays housed within the cooling fan assembly (C0019) on a N/U wire.

The main relay (C0576) is controlled by the ECM (C0913) on a W/K wire. When energised, the main relay provides a feed to the cooling fan assembly (C0019) via fuse 4 of the engine compartment fuse box (C0575) on a Y/U wire.

The ECM constantly monitors engine coolant temperature via the ECT sensor. The ECM (C0914) provides a feed to the ECT sensor (C0169) on a K/G wire. As engine coolant temperature rises, the resistance of the sensor falls. By measuring the voltage returned from the ECT sensor (C0169) on a K/B wire, the ECM (C0914) can determine engine coolant temperature.

Engine Running
With the engine running, the cooling fan can operate at either high or low speed, depending on engine coolant temperature. If the ECT sensor registers a temperature of between 98 °C and 104 °C, the ECM (C0913) energises the low fan speed relay within the cooling fan assembly (COO88) on a U wire. The energised low fan speed relay is then able to supply a feed to the cooling fan motor, which is earthed (COO88) on a B wire!

If the ECT sensor registers a temperature of between 105 °C and 112 °C, the ECM (C0913) energises the high fan speed relay within the cooling fan assembly (COO19) on a U/R wire. The energised high fan speed relay is then able to supply a feed to the cooling fan motor, which is earthed (COO88) on a B wire

The ECMswitches both cooling fan relays off if the ECT sensor registers a temperature of 98 °C or lower.

Engine Stopped
If the ECM registers an engine coolant temperature of above 112 °C while the engine is not running, it will energise the main relay within the engine compartment fuse box. The main relay (C0575) is then able to provide the cooling fan high speed relay (C0019) a feed on a Y /U wire. The high speed relay (COO88) is provided an earth path via the ECM (C0913) on a U/R wire. The energised high fan speed relay supplies a feed to the fan speed motor, which is earthed (COO88) on a B wire.

The cooling fan motor is now able to operate at high speed until the ECT sensor registers a temperature of below 112 °C.

Note: The cooling fan will only operate at high speed when the engine is not running.

KV6
Feed from the positive battery terminal (C0192) is supplied to fusible link 4 and the main relay (C0632) on an R wire. Both are located in the engine compartment fuse box. Fusible link 4 (C0574) supplies a constant battery feed to the cooling fan (C0019) on a N/U wire. This feed is supplied to the low, medium, and high fan speed relays located within the cooling fan assembly.

The main relay (C0578) is controlled by the ECM (C0371) on a W/K wire. When energised, the main relay provides a feed to the cooling fan assembly (COO19) via fuse 4 of the engine compartment fuse box (C0575) on a Y/U wire.
The ECM constantly monitors engine coolant temperature via the ECT sensor. The ECM (C0371) provides a feed to the ECT sensor (C0373) on a K/G wire. As engine coolant temperature rises, the resistance of the sensor falls. By measuring the voltage returned from the ECT sensor (C0373) on a K/B wire, the ECM (C0371) can determine engine coolant temperature.

The ECM controls the operation of all three relays according to the signal it receives from the ECT sensor. If the ECT sensor registers an engine coolant temperature of between 96°C and 100°C, it triggers the ECM (C0371) to provide an earth path for the low fan speed relay (C0088) on a U wire. The energised low fan speed relay drives the fan motor at low speed. The cooling fan assembly (C0088) is earthed on a B wire.

If the ECT sensor registers an engine coolant temperature of between 102°C and 106°C, it triggers the ECM (C0371 ) to provide an earth path for the medium fan speed relay (C0088) on a U/Y wire. The energised medium fan speed relay drives the fan motor at medium speed. The cooling fan assembly (C0088) is earthed on a B wire.

If the ECT sensor registers an engine coolant temperature of between 108°C and 112°C, it triggers the ECM (C0371) to provide an earth path for the high fan speed relay (C0019) on a U/R wire. The energised high fan speed relay drives the fan motor at high speed. The cooling fan assembly (C0088) is earthed on a B wire.

Air Conditioning Request
If air conditioning is requested, Edit:- the cooling fans will automatically operate at _low_ speed, even if the coolant temperature is below 96 deg. C.. If an air conditioning request is received by the ECM when the cooling fan is running at low speed (i.e. the engine coolant temperature is between 96 °C and 100 °C) the ECM will increase the fan speed to medium. If the engine coolant temperature rises above 108 °C the cooling fans operate at high speed as described previously.

ATCU Request
If a request is made by the ATCU via the CAN-BUS for more automatic gearbox cooling, the ECM controls the fan speed as described in the 'Air Conditioning Request' section.

M47R
Feed from the positive battery terminal (C0192) is supplied to fusible link 4 and the main relay (C0632) on an R wire. Both are located in the engine compartment fuse box. The main relay (C0576) is controlled by the ECM (C0603) on a B/K wire.
If the ECT sensor registers an engine coolant temperature of between 100°C and 105°C, the ECM (C0331) will send a PWM signal on a U/R wire to the cooling fan (C0019) requesting low fan speed. The PWM converter within the cooling fan assembly then provides a feed to energise the low fan speed relay. This allows a battery feed from fusible link 4 (C0574) to flow across the low fan speed relay (C0019) and power the cooling fan motor and low speed. The cooling fan motor (C0088) is earthed on a B wire.

If the ECT sensor registers an engine coolant temperature of between 106°C and 111°C, the ECM will send a PWM signal to the PWM converter requesting medium fan speed. The PWM converter will then energise the medium fan speed relay within the cooling fan assembly. This allows a battery feed from fusible link 4 (C0574) to flow across the medium fan speed relay (C0019) and power the cooling fan motor at medium speed. If the ECT sensor registers an engine coolant temperature of between 112°C and 119°C, the ECM will send a PWM signal to the PWM converter requesting high fan speed. The PWM converter will then energise both the low and high fan speed relays. This allows the battery feed from fusible link 4 to power the cooling fan motor at high speed.

Taken from RCL 0311ENG

7th December 2006, 13:59	#2
Keith This is my second home ZT400 Join Date: Oct 2006 Location: Ellesmere Posts: 5,948 Thanks: 0 Thanked 43 Times in 29 Posts	OPERATION K1.8 General Feed from the positive battery terminal (CO192) is supplied to fusible link 4 and the main relay (C0632) on an R wire. Both are located within the engine compartment fuse box. Fusible link 4 (CO574) supplies a constant battery feed to the low and high speed relays housed within the cooling fan assembly (C0019) on a N/U wire. The main relay (C0576) is controlled by the ECM (C0913) on a W/K wire. When energised, the main relay provides a feed to the cooling fan assembly (C0019) via fuse 4 of the engine compartment fuse box (C0575) on a Y/U wire. The ECM constantly monitors engine coolant temperature via the ECT sensor. The ECM (C0914) provides a feed to the ECT sensor (C0169) on a K/G wire. As engine coolant temperature rises, the resistance of the sensor falls. By measuring the voltage returned from the ECT sensor (C0169) on a K/B wire, the ECM (C0914) can determine engine coolant temperature. Engine Running With the engine running, the cooling fan can operate at either high or low speed, depending on engine coolant temperature. If the ECT sensor registers a temperature of between 98 °C and 104 °C, the ECM (C0913) energises the low fan speed relay within the cooling fan assembly (COO88) on a U wire. The energised low fan speed relay is then able to supply a feed to the cooling fan motor, which is earthed (COO88) on a B wire! If the ECT sensor registers a temperature of between 105 °C and 112 °C, the ECM (C0913) energises the high fan speed relay within the cooling fan assembly (COO19) on a U/R wire. The energised high fan speed relay is then able to supply a feed to the cooling fan motor, which is earthed (COO88) on a B wire The ECMswitches both cooling fan relays off if the ECT sensor registers a temperature of 98 °C or lower. Engine Stopped If the ECM registers an engine coolant temperature of above 112 °C while the engine is not running, it will energise the main relay within the engine compartment fuse box. The main relay (C0575) is then able to provide the cooling fan high speed relay (C0019) a feed on a Y /U wire. The high speed relay (COO88) is provided an earth path via the ECM (C0913) on a U/R wire. The energised high fan speed relay supplies a feed to the fan speed motor, which is earthed (COO88) on a B wire. The cooling fan motor is now able to operate at high speed until the ECT sensor registers a temperature of below 112 °C. Note: The cooling fan will only operate at high speed when the engine is not running. KV6 Feed from the positive battery terminal (C0192) is supplied to fusible link 4 and the main relay (C0632) on an R wire. Both are located in the engine compartment fuse box. Fusible link 4 (C0574) supplies a constant battery feed to the cooling fan (C0019) on a N/U wire. This feed is supplied to the low, medium, and high fan speed relays located within the cooling fan assembly. The main relay (C0578) is controlled by the ECM (C0371) on a W/K wire. When energised, the main relay provides a feed to the cooling fan assembly (COO19) via fuse 4 of the engine compartment fuse box (C0575) on a Y/U wire. The ECM constantly monitors engine coolant temperature via the ECT sensor. The ECM (C0371) provides a feed to the ECT sensor (C0373) on a K/G wire. As engine coolant temperature rises, the resistance of the sensor falls. By measuring the voltage returned from the ECT sensor (C0373) on a K/B wire, the ECM (C0371) can determine engine coolant temperature. The ECM controls the operation of all three relays according to the signal it receives from the ECT sensor. If the ECT sensor registers an engine coolant temperature of between 96°C and 100°C, it triggers the ECM (C0371) to provide an earth path for the low fan speed relay (C0088) on a U wire. The energised low fan speed relay drives the fan motor at low speed. The cooling fan assembly (C0088) is earthed on a B wire. If the ECT sensor registers an engine coolant temperature of between 102°C and 106°C, it triggers the ECM (C0371 ) to provide an earth path for the medium fan speed relay (C0088) on a U/Y wire. The energised medium fan speed relay drives the fan motor at medium speed. The cooling fan assembly (C0088) is earthed on a B wire. If the ECT sensor registers an engine coolant temperature of between 108°C and 112°C, it triggers the ECM (C0371) to provide an earth path for the high fan speed relay (C0019) on a U/R wire. The energised high fan speed relay drives the fan motor at high speed. The cooling fan assembly (C0088) is earthed on a B wire. Air Conditioning Request If air conditioning is requested, Edit:- the cooling fans will automatically operate at _low_ speed, even if the coolant temperature is below 96 deg. C.. If an air conditioning request is received by the ECM when the cooling fan is running at low speed (i.e. the engine coolant temperature is between 96 °C and 100 °C) the ECM will increase the fan speed to medium. If the engine coolant temperature rises above 108 °C the cooling fans operate at high speed as described previously. ATCU Request If a request is made by the ATCU via the CAN-BUS for more automatic gearbox cooling, the ECM controls the fan speed as described in the 'Air Conditioning Request' section. M47R Feed from the positive battery terminal (C0192) is supplied to fusible link 4 and the main relay (C0632) on an R wire. Both are located in the engine compartment fuse box. The main relay (C0576) is controlled by the ECM (C0603) on a B/K wire. If the ECT sensor registers an engine coolant temperature of between 100°C and 105°C, the ECM (C0331) will send a PWM signal on a U/R wire to the cooling fan (C0019) requesting low fan speed. The PWM converter within the cooling fan assembly then provides a feed to energise the low fan speed relay. This allows a battery feed from fusible link 4 (C0574) to flow across the low fan speed relay (C0019) and power the cooling fan motor and low speed. The cooling fan motor (C0088) is earthed on a B wire. If the ECT sensor registers an engine coolant temperature of between 106°C and 111°C, the ECM will send a PWM signal to the PWM converter requesting medium fan speed. The PWM converter will then energise the medium fan speed relay within the cooling fan assembly. This allows a battery feed from fusible link 4 (C0574) to flow across the medium fan speed relay (C0019) and power the cooling fan motor at medium speed. If the ECT sensor registers an engine coolant temperature of between 112°C and 119°C, the ECM will send a PWM signal to the PWM converter requesting high fan speed. The PWM converter will then energise both the low and high fan speed relays. This allows the battery feed from fusible link 4 to power the cooling fan motor at high speed. Taken from RCL 0311ENG Last edited by GreyGhost; 4th August 2009 at 14:45..