XC90 AWD V8-4.4L VIN 85 B8444S (2005)
The temperature sensor is an NTC sensor. The sensor is supplied with voltage (signal) from and grounded in the engine control module (ECM).
The resistance in the sensor changes according to the temperature of the fuel. This provides the engine control module (ECM) with a signal of between 0
- 5 V. Low temperature results in high voltage (high resistance). High temperature results in low voltage (low resistance).
The engine control module (ECM) uses the signal to calculate the volume of the fuel.
Oil level sensor
The function of the oil level sensor is to provide the engine control module (ECM) with information regarding the level of engine oil in the oil sump.
The sensor consists of:
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a terminal with three pins
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integrated electronics
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2 capacitive gauge elements
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a PTC resistor.
The oil level sensor is supplied with 5 V by the engine control module (ECM). The oil level sensor generates a pulse width modulated (PWM) signal for
the engine control module (ECM).
The oil level sensor can be diagnosed by the engine control module (ECM).
The pulse-width modulated (PWM) signal from the oil level sensor can be read using parameter readout.
Main relay (system relay)
The function of the main relay (system relay) is to supply certain components with voltage.
The relay is mechanical and has a closing and opening function. In the rest position the circuit in the relay is open.
The main relay terminals (#30 and #86) are supplied with voltage by the battery. When the ignition key has been turned and the engine control module
(ECM) is powered, the terminal (#85) on the main relay is grounded by the engine control module (ECM).
When the terminal (#85) is grounded, the relay is activated and a number of components are powered via the relay terminal (#87).
The main relay is in the integrated relay/fuse box in the engine compartment and is diagnosed by the engine control module (ECM).
Injectors
