Design
Design
Locks
See Design and Function, Central locking.
Inclination sensor module (ISM)
The inclination sensor module (ISM) is on the left-hand side of the rear relay box.
The inclination sensor module (ISM) is powered from the rear electronic module (REM), which both activates and deactivates it. Information is transferred from the inclination sensor module (ISM) to the rear electronic module (REM) using serial communication.
The inclination sensor module (ISM) detects when the angle of the car changes. If the angle changes when the car is alarmed, a signal is transmitted to the rear electronic module (REM) which sends this data out on the controller area network (CAN) to activate the alarm.
There are diagnostics for the Inclination Sensor Module (ISM).
Headlamp range adjustment position sensors (Bi-Xenon)
Cars with Bi-Xenon lamps have a position sensor so that the headlamps can automatically adjust beam length. The vertical adjustment accounts for load and road conditions to reduce the risk of dazzle.
The position sensor is beside the rear axle and is connected to the left-hand rear control arm by a linkage system. This linkage system affects the sensor, allowing the angle of the car to be gauged.
The position sensor is directly connected to the rear electronic module (REM) via three inputs. Two are used for the power supply and ground connection for the sensor. One input is used for signals about the angle of the car. The signals are received by the rear electronic module (REM) which sends them onwards via the Control area network (CAN) to the central electronic module (CEM) which controls the headlamp range adjustment function.
The position sensor can be calibrated using VIDA. The calibration is saved in the rear electronic module (REM) and must be carried out again if the rear electronic module (REM) or position sensor is replaced.
There are diagnostics for the position sensor.
Fuel level (Gasoline/Diesel)
The fuel level in the tank is measured by two sensors. The sensors are located on each side of the fuel tank. Cars with engine B5244S6 have only one sensor, on the pump side. The sensors are directly connected to the rear electronic module (REM).
There are different tables for different fuel tank sizes. These are stored in the rear electronic module (REM) and indicate which sensor values correspond to the remaining fuel in the tank. The rear electronic module (REM) determines which tank is in the car by reading a parameter.
The resistance of the sensor increases as the fuel volume in the tank decreases. The signals from the sensors are compared with the values in the fuel tank table to obtain a value for the remaining fuel volume. This data is displayed by the fuel gauge in the driver information module (DIM).
If the sensors are faulty, the fuel gauge will show 0.
There are diagnostics for the fuel level sensors.
Fuel level (Bi-fuel)
CNG (Compressed Natural Gas)
The fuel level in the gasoline tank operates in the same way as for cars with B5244S6 engines, using a sensor in the tank. A combined pressure and temperature sensor is used to measure the fuel level in the gas tank. The sensor is on the left-hand side of the gas tank.
The sensor is directly connected to the rear electronic module (REM). The signals from the sensor are transmitted to the rear electronic module (REM) where they are calculated and sent to the driver information module (DIM) via the Control area network (CAN).
There are diagnostics for the fuel level sensor.
LPG (Liquefied Petroleum Gas)
The fuel level in the gasoline tank operates in the same way as for cars with B5244S6 engines, using a sensor in the tank.
A sensor, on the right-hand side of the tank, is used to measure the fuel level in the LPG tank. The sensor is directly connected to the rear electronic module (REM). The signals from the sensor are compared with a table stored in the rear electronic module (REM). Data about the remaining volume of fuel is transmitted via the Control area network (CAN) to the driver information module (DIM).
There are diagnostics for the fuel level sensor.
Shut-off valve (Bi-fuel)
There are shut-off valves on the gas tanks to open and close the tank valves on bi-fuel cars.
These are positioned at the inlet/outlet on each gas tank. There is one for LPG and three for CNG.
The valves are controlled electro-magnetically and powered via a relay directly connected to the rear electronic module (REM). The rear electronic module (REM) activates the relay when a request for gas power is transmitted on the controller area network (CAN).
The valves close when the car is running on gasoline, when the ignition is switched off or in the event of a collision.
The valves can be opened via a diagnostic command by activating the relay for the gas valves. Activation is carried out in VIDA via the vehicle communication socket.
The valves can also be closed manually using an Allen key or opened by unscrewing the shut-off valve and replacing it with a special tool.
There are diagnostics for the shut-off valve relay.
Diesel filter preheating (Diesel)
There is a diesel filter on the fuel line from the fuel tank. The rear electronic module (REM) controls warming up the filter by checking the power supply to the filter via a relay. The relay is in the rear relay box.
There is a temperature switch between the rear electronic module (REM) and the relay. The temperature switch closes at approximately -3 °C, which also closes the relay circuit. The temperature switch switches off at approximately 5 °C which breaks the power supply by releasing the relay.
There are diagnostics for the relay circuit for warming up the diesel filter.
Rear fog lamp
The rear fog lamp are in the tail lamps. The fog lamps are operated via a button in the light switch module (LSM). An LED in the button lights when the fog lamps are activated. The rear fog lamp can only be activated when low beam is on (market dependent). The light switch transmits information to the central electronic module (CEM) using serial communication when the button for the rear fog lamp is pressed. The central electronic module (CEM) transmits the data via the Controller area network (CAN) to the rear electronic module (REM). The power supply for the lamps is via a directly connected relay on the rear electronic module (REM).
When reactivating key position II, the function is set to non-activated mode.
In order to detect bulb faults for the rear fog lamp, the rear electronic module (REM) detects the power consumption in the circuit using a directly connected shunt. If the power consumption falls below a certain limit, a fault is indicated and a text message is displayed in the driver information module (DIM).
There are diagnostics for the rear fog lamp relay.
Back-up lamp
There are two back-up (reversing) lamps. These are in the tail lamps. The back-up (reversing) lamp lights when back-up (reverse) gear is selected. The back-up (reversing) lamps are connected to the rear electronic module (REM) via a directly connected relay. The lamps are powered via the relay.
Cars with manual transmissions
Cars with manual transmissions have a back-up (reverse) switch on the transmission. The switch closes and transmits a directly connected signal to the central electronic module (CEM) when back-up (reverse) gear is selected.
There are diagnostics for the back-up (reversing) lamp relay.
Cars with automatic transmissions
In cars with automatic transmissions, a signal is transmitted from the transmission control module (TCM) on the Control area network (CAN) to the central electronic module (CEM) indicating that back-up (reverse) gear is selected.
There are diagnostics for the back-up (reversing) lamp relay.
Brake light
The stop lamps are in the tail lamps. The lamps light when the stop lamp switch on the brake pedal is closed. The stop lamp switch is connected to the central electronic module (CEM). The signal from the stop lamp switch is sent on to the rear electronic module (REM) via a hard-wired cable. The power supply for the lamps is via a directly connected relay on the rear electronic module (REM). In order for the stop lamps to work when the ignition is not on, there is no logic in the rear electronic module (REM) to activate the relay. The relay is activated directly by the signal from the stop lamp switch. The rear electronic module (REM) receives data via the controller area network (CAN) from the central electronic module (CEM) indicating that the stop lamp switch is activated.
In order to detect faults in the stop lamps, the rear electronic module (REM) detects the power consumption in the lamp circuit using a directly connected shunt. If the power consumption falls below a certain limit, a fault is indicated and a text message is displayed in the driver information module.
High level stop lamp (V70/V70XC/XC70/XC90)
There is a high-mounted stop (brake) lamp on the inside of the rear windshield. This lamp lights during braking together with the standard stop lamps. The stop lamp is activated when the stop lamp switch on the brake pedal is closed.
The high mounted stop lamp is supplied with power directly from the rear electronic module (REM). The lamp consists of a number of LEDs.
There are diagnostics for the high level stop lamp.
Rear windshield wiper/washers (V70/V70XC/XC70/XC90)
See Design and Function, central electronic module (CEM).
Rear demist
There are heating loops in the glass for demisting and to prevent ice from forming. The loops heat up when they are supplied with power. The power supply is via a relay on the rear relay box. The relay is controlled by the rear electronic module (REM).
Rear demist is controlled using a switch on the right-hand side of the climate control module (CCM).
The engine must be running for the demister to work. Press the button again to switch off the function. Demisting is switched off automatically after the maximum time of 12 minutes.
The relay can be diagnosed by the rear electronic module (REM). The switch can be diagnosed via the climate control module (CCM).
Electric folding rear head restraints (S60/S80)
There are solenoids on the rear head restraints if the car has electrically folding head restraints (not the center rear seat). The solenoids can fold the head restraints when reversing, for example. The power supply for the solenoids is via a directly connected relay on the rear electronic module (REM).
The head restraints are folded using a switch on the lower section of the climate control module (CCM). The head restraints fold down when the switch is pressed. The head restraints fold back up manually.
The relay for the solenoids can be diagnosed by the rear electronic module (REM). The switch can be diagnosed via the climate control module (CCM).
Cargo compartment lighting (S60/S80/XC90)
There are lamps in the cargo compartment. There are two lamps in the S60/S80. These are on the left and right-hand sides of the cargo compartment panels. In the XC90 there is a lamp in the trunk lid. The lamps light when the trunk lid is open. The cargo compartment lighting is powered directly from the rear electronic module (REM).
There are diagnostics for the cargo compartment lighting.
Rear 12V socket (V70/V70XC/XC70/XC90)
There is a 12V socket on the right-hand side of the cargo compartment. This socket can be used to power a number of accessories.
The socket is directly connected to the 30-supply via a fuse and a directly connected shunt on the rear electronic module (REM).
The rear electronic module (REM) measures the current through the shunt periodically and calculates an average value. This is compared with a limit value to determine if any power consuming component is connected.
This information is transmitted via the Control area network (CAN) to the driver information module (DIM) which displays a text message when a power consuming component is connected (applies only to factory installed 12V sockets).
Parking assistance (applies only to the XC90 2003-2004 and S80 2004)
There is a back-up (reversing) warning system to assist reversing maneuvers. The back-up (reversing) warning system consists of:
- four sensors in the rear bumper
- a parking assistance module (PAM) under the rear relay box.
The parking assistance module (PAM) communicates with the rear electronic module (REM) using serial communication. The signals transmitted contain information about status and diagnostics. The sensors are directly connected to the Parking Assistance Module (PAM). The sensors are also powered via the parking assistance module (PAM).
The back-up (reversing) warning system is activated via a switch on the lower section of the climate control module (CCM). When the system is active, an LED lights in the switch and a text message is displayed in the infotainment control module (ICM) (XC90) or audio module (AUM) (S80).
The sensors detect objects within 1.5 meters and if reverse gear is engaged then a beeping tone can be heard from the rear loudspeakers (XC90) and the front loudspeakers (S80) respectively. The tone intensifies when the car draws closer to the object. At approx. 30 cm the tone becomes continuous.
In the event of a fault in the parking assistance module (PAM) or sensors, the general warning lamp in the driver information module (DIM) lights and a text message is displayed.
There are diagnostics for the back-up (reversing) warning system.