Coolant temperature sensor is a very important part of the engine management system. Its main function is to measure the temperature of the coolant in the engine cooling system. Information obtained from the sensor is used to adjust the parameters of the engine depending on the thermal state, such as engine speed, the quality of the fuel mixture and timing angle. Thus, the sensor makes possible a rapid heating of the engine when you start the car, as well as support of the optimum temperature in all modes.

To date this car part is an indispensable element in the issue of electronic control of the cooling system. Due to it a constant monitoring and engine temperature control is carried out. The recent development is the use of two coolant temperature sensors one of which is mounted on the output of the engine and another on the outlet of the radiator. Coolant temperature is determined depending on the engine load and the crankshaft rotation speed.

It should be said about the causes of some failures of the sensors. The most common problem is increase of the hot engine idle speed when a malfunction indicator lamp is on when the engine is running. To resolve this problem, check the serviceability of the chains and the coolant temperature sensor. This parts should be checked also when the malfunction indicator lamp is on when you switch on the ignition. As for the replacement of the sensor for a new one, you can fully trust to online shops. In addition to excellent prices for the various car parts, such as brake pads or brake booster, when you order online you will also get the best quality products and fast delivery.

Coolant Temperature Sensor (Coolant Sensor) for VW TRANSPORTER IV Bus (70XB, 70XC, 7DB, 7DW), AUDI A6 Avant (4B5, C5), RENAULT TWINGO II (CN0_)

• failure of the conductors connection;
• breakage and disconnection;
• corrosion of the sensor;
• lack of internal resistance of the sensor;
• failure to connect the terminals.

• a significant increase in fuel consumption;
• increased rate of carbon dioxide in the vehicle exhaust;
• difficulty in starting the engine;
• unstable operation of the engine;
• a sharp increase in the electrical resistance of the sensor;
• increase in idle speed.

• manufacturing defects;
• leakage of fluid around the sensor;
• disregard of the rules, guidelines and requirements of the part operation;
• excess lifetime;
• mechanical damage;
• short circuit in the sensor;
• voltage surges.

When the engine is cold the gauge should show a low temperature, and when it’s hot the gauge must define a high temperature. Inadequate indicators show damage. For the diagnosis of the temperature sensor internal resistance an ohmmeter is required. The output of the sensor is diagnosed by means of a voltmeter. Cold sensor will have the average value of about 3V, while heating the voltage level should drop to 0.5 V. Too high voltage says about the lack of grounding and zero voltage is indicative of circuit or no input voltage.

For repairs you will need a bolt, a plug spanner, a rubber stopper. First, you must unscrew the sensor and close the hole with a bolt. Next, cut the bottom of the sensor, carefully clean, wash and dry it. It is necessary to ensure serviceability of the sensor by measuring the resistance with an ohmmeter. Then you need to pour in a solution of an epoxy resin, wait until the end of polymerization and install the item.

Replacement of the temperature sensor should be made not only in the presence of faults, but also after serious overheating of the engine or its replacement. To do this, drain the coolant below the sensor, and then install a new part. The service life of the coolant temperature sensor should not exceed three years.