Hello. I checked my connections and parameters in P508. From the urea level, mega-higher values or 0. The clocks seem to be over 5000 km. Temperature sensors, a few ohms each. (?) - I will check again. Urea temperature in DBox 0 C. Error P20e8, which will delete it, it returns after a few km. The pump works briefly, the solenoid valve too. Clean and dry in the pump block. New nox sensor. I have no ideas anymore. There is a disadvantage in electronics that p20e8 or p20e9 pops up. It is said that this can be avoided at a low cost, but how?
If we connect a bare board, then the ECU will probably detect it as a break in the circuit, so it probably won't be a suitable test. What is this integrated circuit from the fuel level? How to bypass the Hall sensor from the fuel level so that the ECU thinks that the tank is still full, I suspect the urea temperature sensor with the second defect.
Hello. I also have this problem, but for me it does not turn on the tank at all, even for 30 seconds. Do you know where the relay and fuses from adblue are? Diagbox suggests that the relay is blocked, where to look for it?
Subject: urea check service. I took a total of 100km and nothing appears on the clocks. I used the elektroda forum, peugeot .com.pl, peugeotforums. Carmasters, riparando ... I will describe what I did. After removing the tank several times and checking the components, the pump was empty. She will not puff herself even with a full tank !!! I put one of the temperature sensors (the one with lower resistance) in series with a 1kohm resistor, although I am not fully convinced if it did something. I have improved all the plugins. I disconnected the plug from the urea level and inserted a voltage divider from 2 resistors (total about 500kohm) so that the white wire was about 4.2 V In the diagbox in "device test" I chose the performance test (where it is supposed to be 50ml) and instead of a stopper I put a hose (not too short because the liquid can reflect and my face is in urea, I had about 70 cm on hand) and started the test by blowing in the tank, the pump absorbed urea and, in the denox parameters, the pressure rose to more than 5 bar. So far the lights have not come on.
Hello. I have a P20E8 error in Jumper 2019. 30 thousand mileage and the second tank with this error was replaced by the first one under warranty. Since these tanks are so emergency, I decided not to buy a new one right away, but to disassemble and check what could have gone wrong. I undressed everything as in the description. I have no leaks, the plate is dry, the motor is the same, it works for a short time after connecting. In the diagbox, the tank does not pass the pressure build-up and venting test. According to the description, I measured the resistance between the wires leading out of the tank from the elements it has access to, the values are correct. What else could I check? Maybe some element on this board has been damaged? Is there any way to check these items?
Until marr99. I often add adblue to keep the level low. I bypassed the level sensor by disconnecting it and inserting a voltage divider from two resistors so that the input voltage was 4v. I did the test (I do not remember its name, I think the efficiency, it should fly 50ml from the injection (or there from the hose)) but I did not disconnect anything. I filled the tank. I turned on the test and blew into the tank through the hose. The pump will not pull by itself if the system has been disassembled!
The pump will not pull by itself if the system has been disassembled!
In my humble opinion, the above statement is not true. I emptied the tank to zero a few times and refilled it and did not do any tests and everything worked fine. Secondly, the very structure of the tank and the location of the pump in relation to the liquid surface (the pump is as if immersed in urea) causes that, on the principle of vessels connected to the pump, urea is trying to pour in and the only obstacle is the air cushion that forms above the pump, but immediately after starting the pump, the air is displaced and the entire system is easily filled with urea.
I agree with it, but in practice I heard the pump working, the tank under the cap was full and an error popped up, no authorization in the diagbox, too low pressure. I blew it, it dragged, it made a bit of noise and now I did about 1800 km and nothing is displayed
Hi, thanks and congratulations for the topic. I solved the P20E8 problem by adding a 10 kohm resistor in series to the heater temperature sensor (yellow wires). The sensor reading was 330 ohm. Now the temperature seems correct with the ambient temperature (about 30 ° C), the denox system works and injects AdBlue correctly. It was the problem with the heater temperature sensor which after 30 seconds cut power to the tank and the temperature dropped from a correct value to 0 ° C. However, this means that the heating sensor does not work as it should. What could happen with the lowering of temperatures? Could anyone tell me how the heating system works? - Is it the Adblue temperature that activates the heating? Or the heater sensor? - Are the two heating systems (pipe heating and tank heating) independent? Can one activate and not the other? - At what temperature does the heating start? From what I understand the adblue freezes at -11 ° C ... is that the temperature or does the heating start even at 0 ° C for example? - The heater power supply is proportionally controlled as a function of the temperature or is ON / OFF from 0 to 100%. - What is the function of the temperature sensor on the heater? Is it a safety measure to prevent the heater from getting too hot or is it needed to continue heating until a certain temperature is reached? - It seems to me that it is impossible (with diagnostic tool) to read the temperature measured by the heater sensor ... perhaps because the two temperature sensors should have a resistance that varies proportionally between them and therefore the system reads a temperature value that corresponds to the value "average" of the two resistors? I thought about this because if I measure the value of the two blue and yellow wires on the J4 connector of the PCB (which correspond to the two yellow wires on the gray connector), the value is not 10330 ohm but about 5800 ohm ... the connector tracks J4 are somehow related. - Can the heater be activated only when the car is on or does the system control always remain active even when the car is parked and off? - If you disconnect the connector that powers the 100W heater, does the car signal an alarm and cut off the power to the tank? - Is the sensor on the heater of the NTC type? ... Does the resistance increase when the temperature drops? Sorry for the excessive questions but I would like to understand how the heating system works and avoid having problems in case of lower temperatures. Is it possible that the heater gets too hot and causes damage to the tank? In this case perhaps it is better to by-pass (with another resistance) also the Adblue temperature sensor so that the heating is never activated. Of course, in the event of temperatures close to -11 ° C, the tank freezes and this can cause other damage due to the volumetric increase of the adblue. Advice? Thanks in advance for a possible reply. Bye bye.
Good morning, I have a Citroen C4 Grand Picasso 2014 2.0 BlueHDi 150koni. - message - fill in Adblue. Of course, there is Adblue in the tank. All the rest - no mistakes. Is there any way to cheat the signal from the level sensor? Resistor or something? In the end, I have an infusion under the 7th seat and I am able to keep an eye on the level by myself .. Someone wrote above about a similar solution, but in the context of a different tank - the very thought that you have to throw away thousands through "stupid" ideas, makes me sick ... And the car bought 3 weeks ago .....
Hi,
very nice thread, it helped me a lot! I had P20E8 fault code on 2016 C4 grand picasso. I was misled by the "Pressure of the Urea fluid" message. I looked for a pump problem when in fact the problem was with heating of one of the hoses. The one between the tank and injector. The insulation on the connector at the tank had split and water had eroded off one of the wires. It was open loop. I was able to resolder the wiring and fix the problem. The resistance was around 2.5 ohm when correct. When doing the test of the heaters in lexia both heaters failed but as the fault code was for pump pressure I did not look for that first. After resoldering both heaters tested ok.
I also measured the short hose heater in the tank. It was 27 ohms. The not accessible plate was 1.3 ohms.
All ok after this! Hope it can help someone.
Good morning, I have a Citroen C4 Grand Picasso 2014 2.0 BlueHDi 150 horses. - message - refill AdBlue. Of course there is AdBlue in the tank. Everything else - no errors. Is there any way to cheat the signal from the level sensor? A resistor or something? Finally, I have an infusion under the 7th seat and I am able to keep an eye on the level myself. Someone above wrote about a similar solution, but in the context of a different tank - the thought that you have to throw thousands through "dumb" ideas makes me sick ... And the car bought 3 weeks ago.....
I disconnected the black cube in the AdBlue driver (black wires - ground, red - power 5v, yellow - level signal). I soldered two resistors in series between black and red. I do not remember the value of these elements, but about 47k ohm (closer to ground) and 4.7k ohm. The voltage between them should be about 4.5v (connect to yellow) then it will show a range of over 5000km. After cleaning the filter, I now get the P20EE error. New probe. Well, I don't know.
https://www.elektroda.pl/rtvforum/posting.php...ting.php?mode=editpost&p=20290653#https://www. elektroda.pl/rtvforum/posting.php?mode=editpost&p=20290653#After a year after the repair of the AdBlue tank in my car, the whole system works properly and I have no problems. Recently, I was able to thoroughly work out the part of the system to which there is no access because it is located in a non-dismountable part of the tank. I mean two temperature sensors, a fluid level sensor and a heating element. In total, there are four circuits led out with one bundle of wires to the chamber where the AdBlue pump is located. I also developed a way to test these circuits to see if they are working properly and are not causing problems with the tank. Often, dashboard messages do not specify the problem. That's how it was with me where I had a low AdBlue level message and in fact I had a level sensor flooded with urea that stopped working and such a message only misled me. A more correct message would be "no data from fluid level sensor" or "incorrect data" rather than a "fluid level low" message.
I will try to describe each circuit in detail and describe how it can be tested.
1) Temperature sensor that measures the temperature of the fluid (urea) in the area of the filter through which the pump collects urea - two blue wires go to the gray cube.
The tested sensor is immersed in water together with a thermometer sensor that measures the temperature of the water. Readings on an ohmmeter at a given temperature.
To sum up, the above-mentioned sensor is an ordinary 3.3 k? NTC thermistor flooded in a plastic housing with two blue leads to a gray cube. For testing, this thermistor can be replaced with an ordinary 3.3 k? resistor, and in this case we will set a constant urea temperature of about 25.0°C.
2) Temperature sensor placed directly on the heating plate - two yellow wires go to the gray cube.
-------------------------------------------------- -------------------------------------------------- ---------------------- Sensor readings (this is a 10.0 k? SMD NTC thermistor):
The measurements indicate that the sensor placed directly on the heating plate is NTC thermistor 10.0 k? SMD which is used to protect the plate against overheating in the event that, for example, there is no urea in the tank and the heating plate starts to work. The heating plate is 12V and gives 100W power. I made a heating test and after 10 seconds of operation the board reached a temperature of 150 ° C !!!!!!!!!!!!!!!!!!!. and I did not risk further heating it and disconnected the power. I'm afraid that it can easily reach a much higher temperature, maybe even 200 or even 300 ° C !!!! Of course, I made a test in the air, i.e. the plate was removed from the tank and only released heat freely to the environment. In normal conditions, the plate is mounted on a thermally conductive paste to the wall of the tank filled with cold or even frozen urea, it works in completely different conditions and certainly does not reach such temperatures because it quickly gives off heat to the cold environment. Considering what I wrote above, any modifications to the tank, and especially replacing the urea level sensor with resistors, may turn out to be dangerous. This must be done carefully and especially remember to maintain a high level of urea in the tank to always ensure that the heating plate is able to receive heat through the urea. The plate working with an empty tank will probably burn the tank through!!!!! It can even start a fire!!!!. For this reason, the constructors of the tank have secured the tank in several ways and the removal of these protections, making bypasses, etc. must be carefully considered.
To sum up, the temperature sensor placed directly on the heating plate is a 10.0 k? SMD NTC thermistor which is connected with two yellow wires to the gray cube. Its task is to control the temperature of the board and protect it from overheating.
3) Urea level sensor - three wires from the level sensor enter the black cube. black - minus (mass) red - sensor power supply (+5V) white - output - analog signal whose level depends on the position of the float and is in the range of +0.2V to +4.8V
Melexis MLX90360 integrated circuit was used to build the sensor
The MLX90360 integrated circuit from Melexis can be purchased for about PLN 20
The table below shows the working conditions of the output.
As the table shows, with +5V power supply at the output, depending on the position of the float, the voltage is in the range from +0.2V to +4.8V. Conclusion with a faulty level sensor and no possibility of repair because it is located in a non-dismountable part of the tank, the sensor should be disconnected and the voltage should be applied to the cube, e.g. +4.5V, which will be read by the AdBlue system computer that there is a high level of urea!! And after the problem!! Just remember to top up the urea on time.
As my friend wrote earlier harry1250 if we are sure that our level sensor is not working (it is damaged), then in the vicinity of the black cube we cut off the wires (black, red and white) and solder two resistors to the ends with the black cube according to the diagram below:
Attention methe signal wire is white!!! A friend of harry1250 described this cable as yellow, I do not know if he was wrong or there are two versions.
I will present the test of the level sensor in the video
I made the test by connecting the power supply with a voltage of 4.83V to the wires: plus to red negative to black reading the signal from the white wire (voltage measurement between white and black)
With this voltage (4.83V) I powered the level sensor. It should be +5.00V but I didn't have such a precise power supply at hand, so the readings will be minimally low.
In the video the float is shown from the bottom tz. lifting the float on the thread up simulates its descent because I cut off the bottom of the float chamber. In a word, the float in the video is "upside down"
The float in the chamber has a movement of 3.3 cm between its upper maximum position and its lower minimum position. In the lower position of the float (when the tank is almost empty), the voltage on the control cable is +0.4V and when the float reaches the maximum upper position, as the tank is filled with urea, the voltage increases to +4.2V. Further filling of the tank no longer generates any voltage changes because the float can no longer move upwards.
In my car, when the float is in the maximum upper position, I have no message. As it starts to fall, there is information that I can still drive 2,400 km, i.e. at a voltage of about 4.0 V, further falling of the float causes messages that I can drive 1,800 km, 1,300 km, 900 km ......... etc. until the float reaches the lower extreme position (+0.4V) then a message appears that you can still drive 600 km. The height of the tank is about 30 cm and the level sensor controls only the last 3.3 cm, which means it works in a very narrow range, which is crucial for the proper operation of the tank. My tank has a capacity of about 16 liters and allows you to drive about 20,000 km.
Very important note!!!!
If the AdBlue low level message appears, please check the level sensor when repairing the tank, but it may well be other problems with the tank, as my colleagues write about above. The messages are often misleading and suggest not what is really broken. For example, I will quote what Colleague muggeotto wrote a bit above:
" Hi, very nice thread, helped me a lot! I had a P20E8 error code on a 2016 C4 grand picasso. I was confused by the message "Urea fluid pressure". I was looking for a problem with the pump, when in fact it was a problem with one of the hoses heating up. The one between the tank and the injector."
4) Heating plate 12V 100W 1.45?it is used to heat urea at low temperatures because urea freezes at -11 °C. The board has two leads with slightly thicker wires, one green and the other blue to the white cube. In the event of damage to this board, you can theoretically cheat the electronics, but it is not as easy as with temperature sensors because the condition of this board is constantly monitored by a computer that easily detects an open circuit and has two ways to do it. The first is a temperature sensor on the heating element can monitor whether the temperature of the plate increases when it is powered. The second way to monitor the board is much more difficult to work around because it involves changing the shunt through which the current flows to the board. The voltage drop on this shunt is registered by the computer and on this basis the computer knows whether the board is in the circuit and whether it is working. If we replace the board with a resistor, we must use a resistor not 1.45? but a much larger one to limit the power dissipated on it, and this entails replacing the shunt with a resistor with a much higher resistance to keep the same voltage drop on it. It is not difficult and for testing it can be done. I will post a diagram of how to do it and a photo of the shunt on the board. Theoretically, you can do without this tile because it is needed only in winter and in quite severe frosts. If someone keeps the car in a warm garage and the urea freezes sporadically, it is possible to drive without this plate, especially since even if we get a message about AdBlue damage, we can still drive 1000 km.
Good morning, I have a Citroen c4 Grand Picasso 2014 2.0 BlueHdi 150 horses. - message - refill Adblue. Of course there is Adblue in the tank. Everything else - no errors. Is there any way to cheat the signal from the level sensor? A resistor or something? Finally, I have an infusion under the 7th seat and I am able to keep an eye on the level myself. Someone above wrote about a similar solution, but in the context of a different tank - the thought that you have to throw thousands through "dumb" ideas makes me sick ... And the car bought 3 weeks ago.....
I disconnected the black cube in the adblue driver (black wires - ground, red - power + 5v, yellow - level signal). I soldered two resistors in series between black and red. I do not remember the value of these elements, but about 47kohm (closer to ground) and 4.7kohm. The voltage between them should be about 4.5v (connect to yellow) then it will show a range of over 5000km. After cleaning the filter, I now get the P20EE error. New probe. Well, I don't know.
Is your level signal yellow and not white? For me, black, red and white cables go to the black cube!!!
One year after the repair of the AdBlue tank in my car, the whole system works properly and I have no problems. Recently, I was able to thoroughly work out the part of the system to which there is no access because it is located in a non-dismountable part of the tank. I mean two temperature sensors, a fluid level sensor and a heating element. In total, there are four circuits led out with one bundle of wires to the chamber where the AdBlue pump is located. I also developed a way to test these circuits to see if they are working properly and are not causing problems with the tank. Often, dashboard messages do not specify the problem. That's how it was with me where I had a low AdBlue level message and in fact I had a level sensor flooded with urea that stopped working and such a message only misled me. A more correct message would be "no data from fluid level sensor" or "incorrect data" rather than a "fluid level low" message.
I will try to describe each circuit in detail and describe how it can be tested.
1) Temperature sensor that measures the temperature of the fluid (urea) in the area of the filter through which the pump collects urea - two blue wires go to the gray cube.
The tested sensor is immersed in water together with a thermometer sensor that measures the temperature of the water. Readings on an ohmmeter at a given temperature.
To sum up, the above-mentioned sensor is an ordinary 3.3 k? NTC thermistor flooded in a plastic housing with two blue leads to a gray cube. For testing, this thermistor can be replaced with an ordinary 3.3 k? resistor, and in this case we will set a constant urea temperature of about 25.0°C.
2) Temperature sensor placed directly on the heating plate - two yellow wires go to the gray cube.
-----------description in preparation-----------
3) Urea level sensor - three wires from the level sensor enter the black cube. black - minus (mass) red - sensor power supply (+5V) white - output - analog signal whose level depends on the position of the float and is in the range of +0.2V to +4.8V
Melexis MLX90360 integrated circuit was used to build the sensor
The MLX90360 integrated circuit from Melexis can be purchased for about PLN 20
The table below shows the working conditions of the output.
As the table shows, with +5V power supply at the output, depending on the position of the float, the voltage is in the range from +0.2V to +4.8V. Conclusion with a faulty level sensor and no possibility of repair, because it is located in a non-dismountable part of the tank, the sensor should be disconnected and the voltage should be applied to the cube, e.g. +4.5V, which will be read by the AdBlue system computer that there is a high level of urea!! And after the problem!! Just remember to top up the urea on time.
As my friend wrote earlier harry1250 if we are sure that our level sensor is not working (it is damaged), then in the vicinity of the black cube, we cut off the wires (black, red and white) and solder two resistors to the ends with the black cube, according to the diagram below:
Attention, my signal wire is white!!! A friend of harry1250 described this cable as yellow, I do not know if he was wrong or there are two versions.
cdn....
yellow or almost white. It's a signal wire
Added after 37 [minutes]:
It works for me . Two corrections to the electronics of the adblue tank without disassembling the tank are,.,, cheating the tank, i.e. (black cube) on white (yellow) there should be a voltage of approx. 4.5 (he will see it as if it is always full) the second is the temperature sensor of the heating plate adblue in the urea tank (two yellow ones from what I remember) is faulty. I put a 10kohm resistor in series and the system works. I don't ... know ... like in winter ....
It works for me . Two corrections to the electronics of the adblue tank without disassembling the tank are,.,, cheating the tank, i.e. (black cube) on white (yellow) there should be a voltage of approx. 4.5 (he will see it as if it is always full) the second is the temperature sensor of the heating plate adblue in the urea tank (two yellow ones from what I remember) is faulty. I put a 10kohm resistor in series and the system works. I don't ... know ... like in winter ....[/quote]
It is as you describe, two yellow ones are the sensor on the heating plate. These are ordinary NTC SMD 10 kohm MEASURING THERMISTORS. Tomorrow I will make accurate measurements to make sure it's 10kohm. Usually there is a break in this circuit, inserting a resistor in series would not give anything because there would still be a break!! I gave a 10kohm resistor but soldered it to the two yellow wires after cutting off this sensor because it had a break. I don't know what will happen in winter. It all depends if this sensor only controls the heating plate? Is it just overheating protection? Or does it act as a kind of feedback?
Hello. A piece of good work. Without this article, I probably would have been afraid to look there. But to the point. Patient Citroen C4. From 2 months P20E8. Dropped the tank today: - plate like new - valve like new - works from 4V - engine as above - the heaters all look functional - resistances from 1.3ohm (tank heater) to 50ohm the smallest circuits, i.e. at the valve and possibly at the pressure accumulator - I did not check the level sensor, but DiagBox shows 6L, so it is rather functional The only anomaly I found was the board temperature sensor around 700ohm. I understand that if I replace it with a resistor, e.g. 10k, the pump will start, but in winter I can expect a fire :)
I have not read if there is a way to check the pressure sensor.
It is interesting that several times during this period the lights went out for an average of 2 days.
Someone wrote that replacing the battery helped. I didn't want to believe it. After all, when the error appears (engine temperature 70 degrees), the voltage has been over 14V for at least 10 minutes ... But today I'm seriously thinking about it. Maybe some "intelligent" system (BSI?) turns off "less important" systems at the start when it finds that the battery is weak. Jean_Phi wrote that after warming up the engine and turning it off for 30 seconds, everything works. Is it a charged battery?... It's a pity that I didn't check if it would work for me. I do not remember under what circumstances the UREA servis light went out. But the last time was definitely 2 days ago when after an hour's drive I took a half-hour break.
PS my tank is only 3 years old. I don't know if it was mentioned in 2019 or just produced this year, but only one thing comes to mind. What a shit. It is not enough that it breaks down so much that they demand astronomical money for it, although even the smallest piece of the puzzle (except the tank itself) is a separate part that could be easily replaced.
dejaq wrote: The only anomaly I found was the board temperature sensor around 700ohm. I understand that if I replace it with a resistor, e.g. 10k, the pump will start, but in winter I can expect a fire
If the temperature sensor of the heating plate at room temperature, i.e. about 25.0°C, has 700 ?, it is clearly damaged!! At this temperature, it should be about 10 k?. If you replace it with a 10 k? resistor, logically speaking, the heating plate will never be switched on because the computer will always "think" that it is summer, that it is 25.0 ° C !!! and there is no need to heat the urea, so theoretically, with such parameters, the heating circuit will never turn on. And even if it is, maybe only as part of some routine test, but I don't think something like that will happen. But even if you keep the urea level under the cap, nothing will happen. Fire is excluded The problem will appear in the winter when the urea freezes and the computer will still be convinced that it is summer!!!
I do not know if the solution used in the design of the urea heating plate is correct. The plate is a copper sheet with a thickness of about 2mm on which resistance paths are sputtered. The sheet under the influence of temperature undergoes continuous shrinkage and expansion in one word "works". A 10.0 k? SMD NTC thermistor is rigidly soldered to such a sheet.
Added after 56 [minutes]:
There is a very simple method to check the level sensor. You need a voltmeter and a 5V power source. It can even be 3 AA sticks connected in series. Everything is described how to check it. To the black cube with 3 wires from the level sensor (red, black, white) you connect the +5V power supply to power the sensor and on the white wire you read the voltage relative to the ground, i.e. the black wire.
Diagram:
After connecting the power supply and the voltmeter, you put the tank in the position as it is placed in the car and slowly fill the tank with water. On an empty tank you should have a voltmeter reading of around +0.4V as you fill up the voltage will rise to +4.5V and stop at this level even though the tank is not even half full of water. The level sensor measures the level of urea only in the lower range because, as I wrote above, the float's up and down movement is only 3.3 cm and the tank is about 30 cm high. You can also perform a quick test without water by measuring the voltage only in the two extreme positions of the float. So in the position as in the car (reading +0.4V) and after turning the tank "upside down" (reading +4.5V)
Added after 4 [hours] 50 [minutes]:
dejaq wrote: I have not read if there is a way to check the pressure sensor.
Update after pressure testing. I was able to test my sensor at pressures ranging from 0 to 8 bar. Unfortunately, no positive results!! I suspect that my sensor is damaged because it was also splashed with urea and it is possible that the electronics have been damaged. I have a well-prepared test stand to perform such a test, but I don't have another sensor. If anyone has such a sensor, please contact me, I will be happy to test it and send it back to the owner after the tests. I developed a test to check if it works properly without removing the sensor, but without making sure and taking measurements, there is no point in writing about it further.
As for the pressure sensor, it is powered from the same place on the motherboard as the level sensor, i.e. it is powered with +5.0 V. If this voltage was not present, both sensors are de-energized. Here, too, it is the same as in the level sensor, the red wire is +5.0 V, the black wire is ground, and the yellow wire is the output of the signal from the sensor. My observations show that with +5.0 V power supply, if the sensor is only under the influence of atmospheric pressure, i.e. it is loose in the air, then the voltage to ground on the yellow wire is about +4.0 V.
For me, as you can see in the pictures, with +4.83V power supply, the output signal is +3.81V. I don't have a compressor at hand to test what happens to the voltage under pressure, but I suppose that under pressure, the voltage on the yellow wire will drop and may be around +0.5V at 6 bar. Of course, these are just my guesses, maybe someone who has a compressor will make an accurate measurement. I can't rule out that my sensor is damaged and therefore has a signal of about +4.0V at rest. Most pressure sensors behave such that as the pressure increases, the voltage increases here would it be the other way around?
Please, if anyone has exact information about this sensor, give me a link or some info
However, a rather important point has already been made on this subject several times, but I will write it again for the sake of reminder. The pressure reading on the service computer is very misleading. If the system does not work, the pump is damaged, etc., the pressure value on the diagnostic device is 4 bar, and in fact there is no pressure at all. That's how it was with me, the engine was completely flooded with urea, all corroded, as you can see in the pictures, and the diagnostic device showed a pressure of 4 bar, which confused me, I was convinced that the pump was working since I had such a pressure. To sum up, the pressure of 4 bar is such a starting point is the beginning of the scale. Yes, the system is calibrated, the measuring range is 4 to 6 bar and this is measured by the pressure sensor. Any pressure value below 4 or even a pressure of 0 is always read as 4 bar for the measuring system.
this temperature sensor checks the temperature of the heating element, not the temperature of the urea. The second sensor is responsible for the temperature of the urea. The system will work in winter, it will heat the urea but there will be no control over the urea heater, there is the sensor that is failing. Someone has already described it, but I don't remember or on this forum
I mean which one do you mean because I'm lost. I described both sensors in detail above and I didn't make a mistake unless I described something unclearly.
Added after 19 [minutes]:
harry1250 wrote:
the system will work in winter, it will heat the urea but there will be no control over the urea heater, there is the sensor that is failing
I am not so sure if the heater will heat the urea as the sensor controlling the heater will be damaged. This sensor is the protection of the heater. If the computer detects that the heater is heating and the sensor does not confirm it, the heater will be turned off in 100%. That's why he is to monitor the heater, unless the software is written in such a way that the computer is not interested in the temperature of the heater on a regular basis, only when its temperature rises above a certain maximum. If it were as you write, that this sensor is only to protect the heater against overheating, then in normal conditions when there is urea in the tank, the heater never overheats because the second sensor responsible for measuring the temperature of the urea gives a signal that the urea has the right temperature and the computer will turn off the heater . So theoretically, you could drive all winter without a break with a damaged sensor on the heater and there will be no errors. I think that the sensor on the heater checks whether the temperature of the heater during normal operation is within a given range and informs the computer about it on an ongoing basis. I'm afraid that the heater can only work for a while when this sensor is damaged and it is blocked.
Mako122 I meant the sensor about 10k (25°C), yellow wires. He had 700 ohms for me, so I soldered a 10k resistor in series with him and the tank started talking. Maybe it's like you write about monitoring temperature rise or maybe it's overheating protection.
Mako122 I meant the sensor about 10k (25'C), yellow wires. He had 700 ohms for me, so I soldered a 10k resistor in series with him and the tank started talking. Maybe it's like you write about monitoring temperature rise or maybe it's overheating protection.
If you did then my theory rather fails that the heater is monitored all the time unless you did it in the summer and the heater had no reason to turn on and thus there was no opportunity to monitor the heater. Now there may be a problem in the winter because the heater will turn on and it will not be monitored properly because these 10 k is outside the heater and the tank will start leaking errors. I can only guess that if there is a chance to monitor the heater because I have a feedback about its status from the sensor, I would use this information when writing the software. Of course, everything depends on the computing power of the processor, some calculations are not always done if they are not necessary. When writing software for this tank, I would even monitor whether in the summer both sensors show a similar temperature. Because in fact they are a few centimeters apart, none of them has direct contact with urea and when the heater is not heating, both sensors have the same temperature. Be sure to write what will happen in the winter in severe frosts, whether there will be errors.
This 10k thermistor is on the heater board. The last modification of the tank was about 1.5 months ago at a temperature of about 14. Now it's -2 1. So far there are no errors from the tank. We'll see how it goes down.
This 10k thermistor is on the heater board. The last modification of the tank was about 1.5 months ago at a temperature of about 14. Now it's -2 +1 . So far there are no errors from the tank. We'll see how it goes down.
The 10k thermistor is on the board with the heater, but from what I understand you put a 10k resistor in series outside the heater, i.e. in the space where the pump is located, i.e. you set the temperature to about +25.0 ° C. It is not yet known how this thermistor on the heater will behave, whether it has a constant resistance of 700 ? or whether its resistance will change under the influence of temperature. When it becomes severe frost and one sensor on the heater will show +25.0°C all the time and the other, e.g. -25.0°C, it can be interesting. And in fact, it is this sensor that is on the board that shows the temperature of urea better and more accurately, even though it may seem strange, even impossible. Both sensors measure the temperature of virtually the same small enclosed space. They have contact with the urea through the wall of the plastic housing. The sensor on the heater is soldered tightly to the copper plate and the plate adheres closely to this plastic housing through the thermal paste. The temperature measurement path is as follows: urea, plastic housing, thermal paste, copper plate, NTC 10.0 k? SMD thermistor. In the case of the latter sensor, the temperature conduction is much worse. Here, the thermistor is flooded in a rather thick "shoe" which, without thermal insulation paste, is pressed to the plastic housing with a handle. here the temperature conduction path is much worse and looks like this: urea, plastic housing, air, 3.3 k? NTC thermistor flooded in a plastic housing. Both sensors measure urea through the same wall of the plastic housing but then one through the paste and copper and the other through the air and another plastic housing this time of the sensor. Definitely the one on the tile, if it is not heated, has lower inertia and much better thermal conductivity conditions. Anyway, both sensors can generally measure the temperature of urea and the one on the plate even faster and more accurately. The situation is different when the heater is working, because then the sensor on the heater reacts instantly to the temperature of the tile, and the other one, which we conventionally call that it measures the temperature of urea, is also due to the proximity of the tile, it also indirectly measures the heater's temperature less accurately. These two sensors are not far enough apart to measure this only the heater and this only urea. it's a bit of a contractual thing.
After this modification, the displayed temperature of Urea has not changed. And yet it makes no sense to show the temperature of the heating element
Yes, you are right, only I am going to something else, or the temperature difference in winter will not be read by the tank computer as an error because, as I described earlier, both sensors work in almost the same conditions and one will give +25 to the computer and the other -25 and if the programmer he came up with the idea to compare these readings, it will throw an error. I have been programming such industrial automation systems for a long time and such protections were often used as self-monitoring of sensors. Although the two sensors measured something else, it was worth comparing their indications in certain conditions. Let me give an example, one sensor measured the temperature of the water supplying the installations and the other the water returning from the circuit. When the installation is working, the supply is 90.0°C and the return is 40.0°C. Each day before starting the installation, the computer controlling the installation read as part of the test procedure whether the indications of both sensors were the same. Before start-up both pipes were cold they ran side by side and the sensors were close to it and the temperature readings from both sensors should be similar. It cost nothing, did not require additional installations, only one line of the program, and gave information about the state of the sensors. It was some form of sensor self-monitoring. I am curious myself what will happen when there will be a strong frost how the tank will behave. Be sure to let me know.
The discussion focuses on the repair and diagnostics of the AdBlue tank system in PEUGEOT BOXER III and CITROEN JUMPER vehicles, addressing common errors such as P20E8 (low urea pressure) and communication faults with the SCR (Selective Catalytic Reduction) system. Key issues include sensor failures (urea level sensor, temperature sensors on the heating plate and heater circuits), pump and solenoid valve malfunctions, and electronic board damage due to urea corrosion. The tank electronics include a microcontroller (R5F21368WKFP), pump driver circuits with an H-bridge allowing bidirectional pump control, and multiple heating circuits to prevent AdBlue freezing. Repair strategies involve visual inspection for leaks and corrosion, testing and bypassing faulty sensors (e.g., using resistor voltage dividers to simulate full tank level), replacing damaged temperature sensors with 10 kΩ thermistors, and verifying heating circuit resistances. The system requires clearing ECU errors via diagnostic tools (DiagBox) after repairs, as error messages do not always clear automatically. Some users report that the system self-bleeds air over driving distance, negating the need for manual bleeding. The pressure sensor model HM8500J is identified as critical for monitoring AdBlue pressure, with detailed testing performed. The discussion also covers the challenges of tank disassembly and repair, recommending plastic welding over gluing due to ABS plastic construction. Some users mention software or ECU programming to disable or neutralize the AdBlue system as a last resort. The importance of proper electrical connections and CAN bus communication is emphasized, as loss of communication leads to power cutoff to the tank electronics after about 30 seconds. Overall, the thread provides detailed technical insights, component specifications, diagnostic procedures, and practical repair tips for maintaining and restoring AdBlue tank functionality in PSA group diesel vehicles. Summary generated by the language model.
