Coolant sensors
VAUXHALL Meriva Mk II (B) (S10)

The number of coolant temperature sensors in a car can vary depending on the make and model. In the case of the 1.4 petrol turbo Opel Meriva, it typically has two coolant temperature sensors:

1. Engine Coolant Temperature (ECT) Sensor: This sensor is usually located on or near the engine block and provides the engine control unit (ECU) with information about the temperature of the coolant. It helps the ECU adjust fuel mixture and ignition timing for optimal performance and emissions.

2. Temperature Sensor for the Cooling Fan: Some vehicles, including the Meriva, have an additional temperature sensor for the cooling fan. This sensor is responsible for activating the cooling fan when the engine reaches a certain temperature to prevent overheating.

You mentioned that you’ve already changed the one on the top of the engine, which is likely the ECT sensor. If you suspect there may be another sensor related to the cooling fan, it’s typically located on or near the radiator or in the coolant hose leading to the radiator.

To be sure about the specific locations and number of sensors in your Meriva, it’s advisable to consult the vehicle’s service manual or reach out to a dealership or qualified mechanic who can provide precise information for your car’s year and model. They can also assist you in identifying and replacing any additional sensors if necessary.