it's on the radiator, just pull the wires and unscrew it.
Which sensor ???
The coolant temperature sensor on a 1990 Volvo 240 is typically located near the thermostat housing on the engine block. It is usually positioned on the cylinder head or the engine block itself, close to where the upper radiator hose connects. To access it, you may need to remove some components for better visibility. Always ensure the engine is cool before attempting to locate or replace the sensor.
I have a 240 and with the knock sensor unplugged it will still start so I would have to say no.
Connected to the intake air duct.
met poep
on top of bellhousing, behind head, pass-side
O2 sensor/leaky injecters/fuel pressure regulator.
it is located on top of the bell housing behind the engine
To replace the O2 sensor on a 1993 Volvo 240, first, locate the sensor, which is typically found on the exhaust manifold or downpipe. Disconnect the electrical connector and use an O2 sensor socket or wrench to unscrew the old sensor. Install the new sensor by threading it into the same location, tightening it securely, and then reconnecting the electrical connector. Finally, start the engine and check for any error codes or issues.
In a 1991 Volvo 240, the bulb failure sensor is located in the rear driver’s side corner of the engine compartment, mounted on the inner fender. It is part of the vehicle's lighting system, designed to monitor the operation of the vehicle's exterior lights. If a bulb fails, the sensor triggers a warning light on the dashboard. Make sure to check the connections and functionality if you suspect issues with the sensor.
under the dash in the center console, it's big and red.
long answer: yes