NTK’s exhaust gas temperature sensors under the spotlight
The EGTS is an important offering among the NTK Vehicle Electronics brand’s six product lines. This vital piece of equipment is central to ensuring the efficiency and low environmental impact of today’s modern vehicles. It works by monitoring the temperature of turbochargers, catalytic converters, diesel particle filters (DPF) and nitrogen oxide reduction systems. It does this during their operation by measuring the temperature of the car’s exhaust gases and by feeding the data back to the Engine Control Unit (ECU). In this way, the sensor can help protect components from being damaged by excessive heat overload during an engine’s operation. Through effective use, they also enable a reduction in emissions by making sure that the monitored parts are working effectively at all times.
NTK Vehicle Electronics offers no less than 273 EGTS part numbers for both OE and the independent Aftermarket. Coverage of vehicles in operation within the EMEA amounts to 61 million, or 45% of vehicles on the road.
Technical excellence
NTK EGTS have been designed to activate quickly once the engine has been started and then to feed information on the exhaust gases back to the ECU. They are constructed in such a way that makes them resistant to excessive vibration and heat created by the operation of the engine. To optimally measure the vehicle’s emissions, the EGTS can be fitted in numerous places on the engine’s exhaust system, according to the instructions from the car’s manufacturer. These positions include in front or after the turbocharger, before or after the DPF or catalytic converter, before or after the selective catalytic reduction (SCR) system and before or after the exhaust gas recirculation (EGR) valve.
Essentially there are two types of EGTS: the Positive Temperature Coefficient (PTC) and the Negative Temperature Coefficient (NTC). Traditionally, NTCs were seen as the more accurate measuring tool than the PTC units, however, they were limited by their ability to tolerate higher operating temperatures. For this reason, PTCs were generally used to monitor exhaust gases. In answer to this problem, NTK Vehicle Electronics has been able to develop an NTC unit using heat resistant elements that can withstand much higher temperatures than traditional NTCs. As a consequence, all of the brand’s exemplary EGTS components are offered as the more accurate NTC units. Broadly speaking, EGTS can be further subdivided into C- and E-Types, both offered by the Niterra brand. These components can tolerate a temperature range of between -40 °C through to +900°C.
Prior to 2018, NTK Vehicle Electronics offered EGTS with three different cable lengths, all with their own parts number. But from this date onwards, they all received one single length and revised unified part numbers were issued. This had the benefit not only of enabling distributors and workshops to enjoy higher market coverage, but also allows easier stock keeping and a faster turnaround. The change also resulted in better Aftermarket coverage than OE, with the same level of exceptional quality.
Essential maintenance
Given the strategic placement of the EGTS within the exhaust system of a car, it is recommended that any repair, replacement or examination of the component is undertaken by a professional adhering to the manufacturer’s instructions. To correctly check an EGTS, it must first be disconnected from the ECU unit and then either attached to a multimeter or, ideally, an oscilloscope. The sensor must then be allowed to warm up using the engine’s heat, with testing ideally carried out quickly, as the EGTS reaches the correct temperature very swiftly.
As with many critical sensors on modern vehicles, a likely fault with the EGTS will be picked up by the ECU and displayed as an amber “check engine” light on the dashboard. Early signs that an EGTS is not working correctly include reduced fuel efficiency and the failure of other linked components such as the DPF. This is particularly important to note as the filter’s inability to regenerate by burning the particulate matter it has collected can result in a blockage that may require the unit’s replacement, which could end up as very expensive for the consumer. Given the sensor’s position, it may also be necessary to occasionally clean away any buildup of contaminants that it may pick up. This can simply be carried out with a dry cloth.
Conclusion
This feature is part of a series examining the wide range of high-quality automotive components that Niterra provides for both OEMs and Aftermarket with its long-established NGK Ignition Parts and NTK Vehicle Electronics brands. It is intended to offer some technical insight into key parts, such as the EGTS, that are vital for the efficient running of modern vehicle engines. This is the fifth such report and will be followed by an examination of the MAF/MAP sensors.
For further information on NTK Vehicle Electronics brand’s exhaust gas temperature sensors please visit TekniWiki, a technical platform that provides interactive learning modules offering further insightful information on key engine components under www.tekniwiki.com.