Petrol models without air conditioning
Examination
1. Power supply to the fan (am) cooling is supplied through the ignition switch and fuse. On gasoline engines without air conditioning, the fan is controlled by a temperature sensor installed in the radiator on the left side. On gasoline engines with air conditioning and all diesel engines, the fans are controlled by a sensor "Bitron".
2. The fan should turn on when the operating temperature of the engine is exceeded, i.e. a few minutes before the engine temperature indicator needle enters the red sector or before the engine coolant temperature alarm lamp comes on. If the fan does not turn on, remove the wires from the temperature sensor, connect them together and turn on the ignition. If the fan then starts working, the temperature sensor is probably out of order, which must be replaced.
Removing
1. The temperature sensor is installed in the radiator on the left side. Before removing the temperature sensor, the engine and radiator must be cold.
2. Disconnect the negative battery terminal.
3. Partially drain the coolant from the cooling system until the coolant level is below the gauge. Alternatively, you can leave the liquid in the cooling system, and after unscrewing the sensor, very quickly install a plug instead of the sensor. In this case, care must be taken not to damage the radiator.
4. Remove the wires from the sensor contacts.
5. Carefully unscrew the sensor from the radiator.
Installation
1. Replace the O-ring before installing the sensor.
2. The sensor is installed in the reverse order of removal. Tighten the sensor securely and top up the cooling system.
3. Start the engine and warm up to operating temperature. With a further increase in temperature, check the activation of the fan by the sensor.
Air-conditioned petrol models and all diesel models
Cooling fans controlled by sensor "Bitron", which is located in the thermostat housing on the left side of the cylinder head.
Examination
Sensor "Bitron" also controls the air conditioning system, and its operation must be checked at a specialized Peugeot station.
Removal and installation
1. Temperature sensor "Bitron" is screwed into the thermostat housing on petrol engines or the fuel filter housing on diesel engines, which is bolted to the left side of the cylinder head. The sensor can be identified by the brown color of the wire going to the sensor.
2. Removal and installation are the same as previously described for the radiator fan thermal switch.
Coolant temperature sensor in the fuel injection control system
Examination
1. The coolant temperature sensor in the fuel injection control system is screwed into the thermostat housing, which is bolted to the left side of the cylinder head. The sensor can be identified by the green wire going to the sensor.
2. The sensor is a thermistor. Electronic control device (ECU) supplies voltage to the sensor and, by measuring the current flowing through it, determines the temperature of the engine. This information is used by the ECU to control the injector opening time (pulse width). On some models, idle speed and ignition timing are also determined by engine temperature.
3. If the sensor fails, the ECU system enters the backup mode, i.e. takes a predetermined value that will allow the fuel injection system to operate, albeit with less efficiency. In this case, the corresponding alarm lamp on the instrument cluster will light up, which means that if necessary, contact a workshop. This sensor can be tested using Peugeot specific diagnostic equipment. Do not attempt to test the sensor using equipment not designed for this purpose, as could damage the ECU.
Removal and installation
Temperature sensor "Bitron" is screwed into the thermostat housing on petrol engines or the fuel filter housing on diesel engines, which is bolted to the left side of the cylinder head. The sensor can be identified by the brown color of the wire going to the sensor.