Saab Temperature Sensor - Bosch 15393755

Product Information

The engine coolant temperature (ECT) sensor, or simply coolant temp sensor, plays a vital role in monitoring the engine's operating temperature and communicating this information to various vehicle systems. This sensor is located in the engine's coolant passage typically in the cylinder head or block. It works by varying its resistance based on the temperature: as the engine heats up, the resistance decreases, and as it cools down, the resistance increases. The ECT sensor sends this data to the ECU, which uses it for several critical functions, such as the air-fuel mixture, ignition timing, and control of the cooling fans and dashboard temperature gauge. There are many European applications where there is more than one coolant temp sensor, separating the signals used for engine ECU and other functions such as gauges and fans.

A faulty sensor might send incorrect temperature readings to the ECU, resulting in poor engine performance. The most common example is if the sensor incorrectly signals that the engine is colder than it is, the ECU will enrich the air-fuel mixture unnecessarily, leading to rough idling, poor fuel economy, or even black smoke from the exhaust due to unburnt fuel.

Conversely, if the sensor falsely indicates an engine overheating condition, the ECU might trigger warning lights, prematurely activate the cooling fans, or even cause the car to go into "limp mode," limiting engine power to prevent damage (however this is a rarer failure mode).

• Wrong Temp Readings: If the coolant temperature gauge is acting unpredictably, or reading consistently too high or too low, it may be either a coolant temperature sensor or a thermostat. Because of this, it’s common to replace both of these parts at the same time for the best probability of success while the cooling system is opened.
• Running too rich: If you have noticed the temperature gauge is low and the exhaust is black and sooty, the engine might be stuck in the warm-up loop due to a bad coolant temperature sensor even though the engine is at the proper operating temperature controlled by the thermostat.
• Non-linear or suspicious live data output: For vehicles equipped with OBDII, use a scan tool to monitor the exact temperatures being output from the sensor. As the car warms up the output should be smooth and linear. If there are dead spots or it acts suspiciously, you may need to replace the sensor.

About Bosch

Bosch is one of the worlds leading suppliers of engine electronics and sensors. Their sensors and modules can be found in almost every modern car on the planet. Bosch Automotive offers a comprehensive portfolio of unmatched solutions for every job. From diverse diagnostic solutions and OE-quality auto parts, to industry-leading software and unmatched vehicle coverage, to innovative charging, repair and maintenance tools. Making repair and maintenance more effective, efficient, and sustainable for the vehicles of yesterday, today and tomorrow. With over 130 years of experience in the automotive industry, Bosch continues to lead the way in automotive innovation by inventing and developing quality products and solutions that focus on customer needs, shaping the future, and the continued pursuit of excellence.

Robert Bosch founded the “Workshop for Precision Mechanics and Electrical Engineering” in Stuttgart, Germany in 1886. Since the beginning Bosch has been a leader in innovation and development. They introduced fuel injection into mass production in 1967 laying the foundation for modern ignition electronics. Bosch brought lambda sensors to market in 1976, paving the way for cleaner exhaust gases and better fuel economy.

With millions of parts and products in their product line, Bosch offers everything from brake pads to household tools and medical supplies. FCP Euro has partnered with Bosch for the 2019 TC America Championship. They are a sponsor on our 2018 Volkswagen GTI TCR race cars. We offer Bosch's full line of OE and OEM components for your European vehicle.