Rashman4u Posted May 13 Share Posted May 13 Greetings, I have observed that the radiator fans on my E270 are operating continuously upon starting the vehicle. This occurs when the air conditioning and heating systems are both turned off. The engine temperature is within the typical range, and the coolant level is at an appropriate level. I have conducted a comprehensive check for fault codes and can confirm that everything is functioning properly. Do you have any recommendations? It is possible that the temperature transmitter for the fan is defective. Thank you. Quote Link to comment Share on other sites More sharing options...
Matt865 Posted May 13 Share Posted May 13 This often occurs when the fan control unit loses its CAN-bus connection with the engine or AC controller. To safeguard the engine, the radiator fan(s) are set to operate at maximum speed. However, this scenario often leads to the generation of error codes. Regardless: Inspect the cables and connectors for any faulty connections, corrosion, or misalignment of the contact components in the plugs or sockets. There have been instances when workshops have mistakenly changed controllers due to error messages indicating a lost connection, incorrectly supposing that the hardware (controller) was faulty. Several electrical issues may be attributed to mechanical faults. I strongly recommend that those who want assistance do the necessary inspections on their own. An especially troublesome issue that has arisen is the use of "Z-joints". Auto manufacturers have used the practice of including joints inside cable harnesses to reduce costs, specifically for the purpose of sharing a ground connection. Indeed, there have been several instances of this, leading to a range of issues that are not always straightforward to resolve. Yet another ill-advised move, in my humble opinion, has been the use of excessively thin wires in harnesses designed for sensors that are not capable of carrying substantial electrical currents. If a harness is bent carelessly for whatever reason, the tiny wires are stretched past their breaking point, resulting in the creation of open circuits. This leads to inaccurate sensor measurements. Quote Link to comment Share on other sites More sharing options...
keithmerc220 Posted May 13 Share Posted May 13 If the fan starts around 10 seconds after the engine has been started, it is possible that the cause is either insufficient air conditioning pressure or a malfunctioning air conditioning pressure sensor. Do you possess iCarsoft? Is it possible to assess the air conditioning system pressure both while the automobile is turned off and when it is running? If so, what are the corresponding measurements obtained? Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 Thank you for the advice so far. I do own the iCarsoft device. I will examine it. Meanwhile, I have once again entered the automobile, started its ignition, and a few seconds later, activated the fans. Subsequently, I saw that the temperature gauge rapidly rose to 90 degrees Celsius. then, it increased to a temperature of 120 degrees Celsius and then decreased to 90 degrees Celsius. Therefore, it is probable that the temperature sensor is the cause. What is your opinion, gentlemen? Quote Link to comment Share on other sites More sharing options...
clk320x4 Posted May 13 Share Posted May 13 Undoubtedly seems to be a suspect. On the icarsoft device, you will have the capability to see the precise temperature sensor readings. Quote Link to comment Share on other sites More sharing options...
clk320x4 Posted May 13 Share Posted May 13 The fan controller used Pulse Width Modulation (PWM) to regulate the fan's speed. Additionally, the diagnostic signal is grounded to enable the fan controller to communicate any issues to the Engine Control Unit (ECU). LIN may be a cost-effective option, since it is affordable and sufficiently quick. However, using CAN as a controller would significantly increase the expenses. Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 The coolant temperature sensor is located inside the thermostat housing. I still possess the previous thermostat housing that I changed five years ago. I will attempt to transfer the sensor to the new housing when I get the opportunity. Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 Tell me about LIN. Quote Link to comment Share on other sites More sharing options...
clk320x4 Posted May 13 Share Posted May 13 Local Interconnect Network (LIN). The system operates on a 12-volt power supply and uses serial communication. A single master device, such as an ECU, governs one or several subordinate devices, such as a glow controller and an alternator. The slaves only transmit data in response to a request initiated by their master. That is distinct from the Controller Area Network (CAN) protocol, where each device functions as a master and autonomously transmits data without requiring explicit requests. Quote Link to comment Share on other sites More sharing options...
bvlenci Posted May 13 Share Posted May 13 Inspect the fan relay for any stickiness. Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 However, it is important to note that the temperature sensor is not affected by any interference that might potentially distort the temperature readings. Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 This morning, I inserted the key into the ignition and turned it on without starting the engine. Immediately, the temperature readout rapidly increased to 90 degrees Celsius. The first phase was challenging, indicating a potential issue with the temperature sensor. This might result in incorrect fuel settings as the engine is really cold, while the computer incorrectly assumes it has reached operating temperature. I will attempt to use the other sensor on Sunday. I performed a scan of the air conditioning system pressure, as previously recommended, and the readout indicates a pressure of 3 bar. Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 I recently tested the alternate sensor by connecting it while leaving it suspended in the open air, without enclosing it in its protective shell. The temperature stayed stable and the fans did not activate, thereby confirming its functionality. I have attempted to detach the functional sensor from its previous housing, but it is firmly stuck and resistant to removal. Consequently, the sensor in the vehicle is likely to provide the same challenge. There is a possibility of damaging the sensor's socket if I persist in trying to remove it. Therefore, it seems that the most viable solution is to replace the whole housing unit with a new one. Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 There is an issue with the parts supplier, specifically with the brand called Topran. Although they claim to provide original equipment manufacturer (OEM) parts, I have personally experienced a scam from a supplier called Autodoc. They manipulated my order and substituted a part from a manufacturer called Stark, which is apparently a Chinese company owned by Autodoc. This deceptive practice has affected other customers as well, as indicated by online reports. Authorised retailers are now experiencing a total lack of inventory, with excessively extended waiting periods that are so uncertain that they cannot even provide an estimated restocking date. Â Quote Link to comment Share on other sites More sharing options...
clk320x4 Posted May 13 Share Posted May 13 I replaced the faulty component on my E220 with a Mahle replacement. You should be able to simply get one of them. Â Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 From whence did you get yours? The Euro currency does not display any specific information. The GSF simply indicates that the product is of premium quality. However, during my last purchase from GSF, I received a Calorstat, which is generally known for its reliability. Unfortunately, I was unaware of the exact product I was being supplied with until I received it. Quote Link to comment Share on other sites More sharing options...
clk320x4 Posted May 13 Share Posted May 13 The source of the item was Partsinmotion, more precisely their eBay shop named partsinmotion. It seems that the item is no longer available for sale, however please be aware that there are alternative options that appear to contain the same component. The item is categorised and identified by its Mahle part number, thus it will not appear in search results if you search for E270. Uncertain whether this is identical to yours Quote Link to comment Share on other sites More sharing options...
clk320x4 Posted May 13 Share Posted May 13 https://www.ebay.co.uk/itm/313000908756?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=oKZ3Yp7_TDK&sssrc=4429486&ssuid=1kh8SLZbTGS&var=&widget_ver=artemis&media=COPY&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338181125&toolid=10001&customid=2518X1570512X0ddeaf5d13e14d03bef53658a6dbcdc9 Quote Link to comment Share on other sites More sharing options...
Rashman4u Posted May 13 Author Share Posted May 13 As an update, I successfully replaced just the temperature sensor. In the original Mercedes model, I had difficulty in removing the sensor. However, I saw that the sensor in this Calorstat model had the ability to rotate. Therefore, I attempted to remove it and succeeded. Consequently, I proceeded to replace the sensor, resulting in a successful outcome. Subsequently, once this occurs, all aspects return to their proper state, with fans and temperature functioning optimally. Quote Link to comment Share on other sites More sharing options...
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