Tank Temperature Sensor: MIL & Reducing Agents

Hello everyone,

I'm new here and just got my VCDS as well. If everything was okay, I wouldn't have bought the VCDS in the first place... ;D

I have tried searching using the following keywords:
- Sensor for tank temperature reduction agent.
- P205C
- 008284
- VW Crafter
- AdBlue (but that's a very broad term...)

Regarding the error itself:

The indicator light suddenly lit up without any warning!

Then I used a VCDS tool and simply cleared the error code, and it worked fine for a while. However, after starting the vehicle twice, the MIL (Malfunction Indicator Lamp) came back on again. Clear the error – start the car twice – the error reappears.

So, it's something serious after all :-/

Since I've already searched the internet for relevant keywords but haven't found anything that fits perfectly, I wanted to tap into your expertise.

I have an AdBlue tank. It's full of AdBlue because I just filled it up a few kilometers ago.

The tank is leak-proof and there are no leaks anywhere. The tank and surrounding area are dry.

The error doesn't occur while driving, but only when I start the engine/system.

I think the NOx values are okay (but I don't really know anything about it). Otherwise, I build cement plants.

The vehicle exhibits no loss of power during operation.

My question is therefore:

What is it?
What do I need to exchange?
Could a software update from Volkswagen help?
Have you ever experienced that before?

Here is the car scan with the error message:

Code:

Samstag,09,Juli,2016,18:17:55:21791 VCDS -- Windows-basierter VAG/VAS-Emulator läuft auf Windows 10 x64 VCDS Version: RKS 15.7.4.1 Datenstand: 20160602 http://shop.dieselschrauber.de Händler-/Werkstattname: Simon Fahrzeug-Ident.-Nr.: WV1ZZZ2EZA6026137   KFZ-Kennzeichen: Fahrzeugtyp: 2E (2E - VW Crafter (LT3 / 2006 >)) Scan: 01 91 92 93 94 95 96 97 98 99 9A 9B 9C 9D 9E 9F A0 A1 A2 A3           B0 B1 B2 B3 B4 B5 B6 C1 Fahrzeug-Ident.-Nr.: WV1ZZZ2EZA6026137    ------------------------------------------------------------------------------- Adresse 01: Motorelektronik (CEC)       Labeldatei: DRV\076-906-022-CEC.clb    Teilenummer SW: 076 906 022 Q    HW: 076 906 022 G    Bauteil: R5 2,5L EDC A020SG  7729     Revision: 24H34---    Seriennummer: VWXDZ0J1009340    Codierung: 0003072    Betriebsnr.: WSC 28975 134 94397    VCID: 214E5A4DFB9CF53651-5132 1 Fehler gefunden: 008284 - Geber für Tanktemperatur Reduktionsmittel                P205C - 000 - Kurzschluss nach Masse              Umgebungsbedingungen:                     Fehlerstatus: 01100000                     Fehlerpriorität: 2                     Fehlerhäufigkeit: 1                     Verlernzähler: 255                     Zeitangabe: 0              Umgebungsbedingungen:                     Drehzahl: 0 /min                         0.00 %                     Spannung: 12.31 V                     Temperatur: 18.0°C                         0.0 bar                     Temperatur: 79.2°C                     Last: 80.4 % Readiness: 0 0 0 0 1 ------------------------------------------------------------------------------- Adresse 91: Motorelektronik        Labeldatei: DRV\076-906-022-CEC.clb    Teilenummer SW: 076 906 022 Q    HW: 076 906 022 G    Bauteil: R5 2,5L EDC A020SG  7729     Revision: 24H34---    Seriennummer: VWXDZ0J1009340    Codierung: 0003072    Betriebsnr.: WSC 28975 134 94397    VCID: 214E5A4DF89CF53651-8074 1 Fehler gefunden: 008284 - Geber für Tanktemperatur Reduktionsmittel                P205C - 000 - Kurzschluss nach Masse              Umgebungsbedingungen:                     Fehlerstatus: 01100000                     Fehlerpriorität: 2                     Fehlerhäufigkeit: 1                     Verlernzähler: 255                     Zeitangabe: 0              Umgebungsbedingungen:                     Drehzahl: 0 /min                         0.00 %                     Spannung: 12.31 V                     Temperatur: 18.0°C                         0.0 bar                     Temperatur: 79.2°C                     Last: 80.4 % ------------------------------------------------------------------------------- Adresse 93: Wegfahrsicherung        Labeldatei: DRV\2E0-905-865-93.clb    Teilenummer SW: 2E0 905 865 AD    HW: 906 545 580 8    Bauteil: IMMO          0805  0815     Revision: 00805000    Seriennummer: VWXDZ0J1009340    Betriebsnr.: WSC 00000 000 00000    VCID: 6DD6767D74C4E156A5-8038 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 94: Airbag        Labeldatei: Keine    Teilenummer HW: 9064461442    Betriebsnr.: WSC 00117 555 00000    ASAM Datensatz: 3 3332    ROD: CRFT_AB_3_3332.rod (*)    VCID: 55A63E9D345449967D-8000 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 95: Bremsenelektronik        Labeldatei: Keine    Teilenummer SW: 9069022800    HW: 0004460153    Betriebsnr.: WSC 00117 555 00000    ASAM Datensatz: 3 4101    ROD: CRFT_ESP_3_4101.rod (*)    VCID: 040033D98F4E001E5A-8050 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 96: Schalttafeleinsatz        Labeldatei: Keine    Teilenummer SW: 9069024700    HW: 9069011800    Betriebsnr.: WSC 00000 000 00000    ASAM Datensatz: 32 786    ROD: CRFT_KOMBI_32_786.rod (*)    VCID: 05062EDD847439164D-8050 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 97: Fahrtenschreiber        Labeldatei: Keine    Teilenummer SW: eB""""""    HW: 9065420410    Bauteil: TCO             Seriennummer: 000000000017673    ASAM Datensatz: CRFT2_FAHRT 121    ROD: CRFT1_FAHRT.rod    VCID: 173A7495EED8BB86AF-8042 5 Fehlercodes gefunden: 2000 - ROD - Unbekannter Fehlercode             Prüfung abgeschlossen - nicht aktiv 80000 - ROD - Unbekannter Fehlercode             Prüfung nicht abgeschlossen - nicht aktiv              Umgebungsbedingungen:                     Fehlerstatus: 00000001                     Fehlerpriorität: 0                     Kilometerstand: 983040 km 608800 - ROD - Unbekannter Fehlercode             Prüfung abgeschlossen - nicht aktiv 0400 - ROD - Unbekannter Fehlercode             Prüfung abgeschlossen - nicht aktiv              Umgebungsbedingungen:                     Fehlerstatus: 00000001                     Fehlerpriorität: 1                     Fehlerhäufigkeit: 44                     Verlernzähler: 44                     Kilometerstand: 919551 km 0500 - ROD - Unbekannter Fehlercode             Warnleuchte EIN - Prüfung nicht abgeschlossen - gespeichert ------------------------------------------------------------------------------- Adresse 99: Zündstartschalter        Labeldatei: Keine    Teilenummer HW: 9065455808    Betriebsnr.: WSC 00117 555 00000    ASAM Datensatz: 67 257    ROD: CRFT_EZS_67_257.rod (*)    VCID: 55A63E9D345449967D-8000 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 9A: Funkfernbedienung        Labeldatei: DRV\2E0-905-865-9A.clb    Teilenummer SW: 2E0 905 865 AD    HW: 906 545 580 8    Bauteil: HF-FFB        0805  0815     Revision: 00805000    Seriennummer: 12345678901234    Betriebsnr.: WSC 00000 000 00000    VCID: 6DD6767D74C4E156A5-8038 1 Fehler gefunden: 00172 - Schlüssel 2 nicht gelernt             000 - - - Sporadisch ------------------------------------------------------------------------------- Adresse 9B: Türelektr. Fahrer        Labeldatei: Keine    Teilenummer HW: 9068205626    Betriebsnr.: WSC 00000 000 00000    ASAM Datensatz: 33 260    ROD: CRFT_FTUHR_33_260.rod    VCID: 55A63E9D345449967D-8000 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse 9C: Heizung/Klima        Labeldatei: Keine    Teilenummer SW: 2514450200    HW: 9068300885    ASAM Datensatz: 21 2    ROD: CRFT_KLIMA_21_2.rod (*)    VCID: 77FA5415CE985B864F-8022 1 Fehler gefunden: 9301 - Stellmotor der Temperaturklappe (V68): defekt/Unterbrechung/Kurzschluss             Prüfung abgeschlossen - gespeichert ------------------------------------------------------------------------------- Adresse 9F: Standheizung        Labeldatei: Keine    Teilenummer HW: 9064460629    ASAM Datensatz: 98 257    ROD: CRFT_STH_98_257.rod (*)    VCID: 55A63E9D345449967D-8000 1 Fehler gefunden: 9016 - Verbrennungsluftgebläse (V6): Unterbrechung             Prüfung abgeschlossen - gespeichert ------------------------------------------------------------------------------- Adresse B1: Bedienfeld        Labeldatei: Keine    Teilenummer HW: 9065453507    Betriebsnr.: WSC 00000 000 00000    ASAM Datensatz: 67 3    ROD: CRFT1_OBF_67_3.rod (*)    VCID: 55A63E9D345449967D-8000 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse B2: Einparkhilfe        Labeldatei: Keine    Teilenummer SW: 9069024200    HW: 0004460056    Betriebsnr.: WSC 00117 555 00000    ASAM Datensatz: 3 769    ROD: CRFT1_EPH_3_769.rod (*)    VCID: 55A63E9D345449967D-8000 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse B3: Anhängerfunktion        Labeldatei: Keine    Teilenummer HW: 1695455632    ASAM Datensatz: 21 4    ROD: CRFT_TRL_21_4.rod (*)    VCID: 55A63E9D345449967D-8000 Kein(e) Fehlercode(s) gefunden. ------------------------------------------------------------------------------- Adresse B4: Zentralelektrik        Labeldatei: Keine    Teilenummer SW: 9064420700    HW: 9065453801    Betriebsnr.: WSC 00000 000 00000    ASAM Datensatz: 33 772    ROD: CRFT_EZE_33_772.rod (*)    VCID: 55A63E9D345449967D-8000 1 Fehler gefunden: 9007 - Lampe für Abblendlichtscheinwerfer links (M29): Kurzschluss nach Plus             Prüfung abgeschlossen - aktiv/gespeichert ------------------------------------------------------------------------------- Adresse B6: Lenkradelektronik        Labeldatei: Keine    Teilenummer SW: 9065402545    HW: 9065402545    Betriebsnr.: WSC 00000 000 00000    ASAM Datensatz: 72 257    ROD: CRFT_SML_72_257.rod (*)    VCID: 081827E9B366247E36-805C Kein(e) Fehlercode(s) gefunden. Ende----------------------------(Dauer: 03:57)-----------------------------

Quote:

008284 - Sensor for tank temperature reduction agent. P205C - 000 - Short circuit to ground. Environmental conditions: Error status: 01100000 Error priority: 2 Error frequency: 1. Lost Count: 255 Time: 0

Hi,

The error is actually quite clear:
Either the wiring or a connector involved in the temperature sensor for the AdBlue tank is faulty, or the sensor itself is defective.

Why don't you simply use a multimeter to test the sensor? There shouldn't be that many sensors/cables leading to the AdBlue tank.

Best regards, Rainer.

Thank you very much, great idea!

What values can I expect there? Which values are within the tolerance range (for voltage and resistance), and which are not?

Can the sender unit be replaced separately from the tank, as reported in other forums? Are there any repair kits available?

Which cable connects to the temperature sensor? What is the color of the cable, and what value does it represent? Is it a resistance thermometer (RTD) or a thermocouple?

I don't have a wiring diagram (unfortunately), or is it not absolutely necessary?

Do the ambient conditions indicate the current battery value, or does the measured voltage at the temperature sensor provide that information?

Are the 18.0°C the current temperature at the sensor?

What is the voltage/resistance in this case?

Why am I only seeing the error message every other time?

Why is an error message being displayed at 18°C? Yesterday, a temperature of 18°C in my surroundings was a plausible reading.

Die zweite Temperatur ist die am... Yes, where?

Environmental conditions:

Speed: 0 RPM.

0.00%

Voltage: 12.31 V

Temperature: 18.0°C

0.0 bar

Temperature: 79.2°C

Last: 80.4%

I've also looked at the exploded diagram of the tank and all its components. However, I only find the pump and heating element in the diagram, but no sensors. There are no level sensors or temperature sensors shown. Therefore, I don't know which cables to expect or what values they might provide.

Can you tell me that?

Thank you again, and thank you in advance.

You can find information about the functionality and structure of the SCR system in document SSP 424.

The temperature sensor (G685) for the reducing agent is located in the dosing module for the reducing agent, which is inside the AdBlue tank. See page 28 and following in document SSP 424.
You can find details about the G685 on page 47 of the SSP document.

It looks like it could be an expensive undertaking, as it's unclear whether it's possible to access the donor unit within the support module or even replace it.

Best regards,
Rainer

It's only available as a complete set and costs around €180-200.

Thank you very much!

The tip about the SSP 424 is invaluable. Today, I was under the car and identified the connector that is responsible for, among other things, the temperature sensor.

It's an eight-pin, rectangular connector located on the passenger side, in front of the fuel tank.

I had VCDS running the entire time and I was able to observe how the "Coolant Temperature Sensor" reading jumped from +79.2°C to around -40°C.

I found this out using SSP 424:

The sensor is an NTC (Negative Temperature Coefficient) thermistor.

Means:

The electrical resistance of the sensor.
It decreases as the temperature of the reducing agent increases.

If I disconnect the plug, the resistance becomes infinite, and the control unit interprets this as the lowest temperature!

And I found out with the help of SSP 424:


The temperature sensor (sender G685) is connected directly to the engine control unit without being processed or filtered beforehand.

Therefore, I thought I could identify the cable. I spent 2 hours underneath the car, but I couldn't identify the cable for the sensor. Of the eight cables, six are outputting a voltage. Four have 12V, and two have 10V. The ground was measured.

I tried using two cables to identify the correct voltage source for the sensor and the resistor line, but I haven't been successful. Unfortunately, I don't know the color of the cable, or I might have to try them all. I'm almost finished trying them out.

The funniest part is yet to come. After I unplugged the cable about 6 times, the error message changed; here it is for you to read:

Code:

Montag,11,Juli,2016,20:16:41:21791 VCDS -- Windows-basierter VAG/VAS-Emulator läuft auf Windows 10 x64 VCDS Version: RKS 15.7.4.1 Datenstand: 20160602 http://shop.dieselschrauber.de Händler-/Werkstattname: Fahrzeug-Ident.-Nr.: WV1ZZZ2EZA6026137   KFZ-Kennzeichen: HSK-L6163 Kilometerstand:    Reparaturauftrag: hankes11-7-16 -------------------------------------------------------------------------------- --------------------------------------------------------------------------------                 Adresse 91: Motorelektronik       Labeldatei: DRV\076-906-022-CEC.clb    Steuergerät-Teilenummer: 076 906 022 Q    HW: 076 906 022 G   Bauteil und/oder Version: R5 2,5L EDC A020SG  7729                  Codierung: 0003072             Betriebsnummer: WSC 28975 134 94397                       VCID: 214E5A4DF89CF53651-8074 1 Fehler gefunden: 008283 - Geber für Tanktemperatur Reduktionsmittel                P205B - 000 - unplausibles Signal              Umgebungsbedingungen:                     Fehlerstatus: 01100000                     Fehlerpriorität: 2                     Fehlerhäufigkeit: 1                     Verlernzähler: 255                     Zeitangabe: 0              Umgebungsbedingungen:                     Drehzahl: 714 /min                     Spannung: 12.54 V                     Last: 80.4 %                     Temperatur: 20.7°C                     Temperatur: 77.4°C                     Temperatur: 20.7°C                     Temperatur: 18.0°C

That means the error originated from:
Donor for tank temperature reduction agents.

P205C - 000 - Short circuit to ground.

modified from:

Donor for tank temperature reduction agents.
P205B - 000 - Implausible signal.

The funny thing is, I didn't do anything – except figure out which of the cables was connected to my sensor by tracing a few wires.

It looks to me more like a loose connection.

Thank you for the tip about the part.

Yes, the sensor, whether it's for temperature or level, is only available when connected to the heating system.

It costs around 400 euros directly from VW. Is it also available as an accessory? I haven't checked yet.

Thank you again!

For the Sharan, it costs around €200, but I didn't know that it was twice as expensive for the Crafter.

For the G685, there should be a black 4-pin connector on the reducer tank. Pin 3 is green/white, and pin 4 is white/brown. These wires then connect to a black 9-pin connector located on the underside of the vehicle, on the right side. Pin 1 is green/white, and pin 2 is white/brown. However, this configuration depends on whether it's a cab or a double cab with a truck bed.

I would suspect that the implausible signal you're getting is due to the disconnected connector and the ignition being turned "on" while taking measurements.

On page 47 of the German datasheet (SSP), you can find the resistance curve for the NTC thermistor. At 25°C, the resistance is approximately 10 kOhms.

Quote:

NTC 10K 1.0 :: NTC Thermistor, 10 kOhms, 1% accuracy. NTC Thermistor, 10 kOhms, 1%, MEASUREMENT SPECIALTIES GAG10K3435A1. Article No.: NTC 10K 1.0 1.30 €

For the difference of 400 euros, one could certainly invest some time in crafting or DIY projects.

Thank you very much for the information!

I'm going to test the plug with a multimeter tonight! Now I also know what colors the wires are.

Thank you also for the values that I should be receiving.

I will report back when I have found out something new. For that much money, it might be worth installing a temperature sensor yourself and connecting it to the control unit .

I'll try to figure it out.

Thank you again, you have helped me a lot!

Hey everyone,

I removed the AdBlue tank, disassembled the heater, and disconnected the temperature sensor G685.

As can be seen from the SSP 424 document, the temperature sensor is welded together with the level indicator G697 in a single unit.

The colors gray/white and white/brown were very helpful! In my case, pins 3 and 4 were located on the tank. After the connector, the colors gray/white and white/brown correspond to black and white.

My measured return resistance was 0.83 ohms.

I had ordered the recommended sensor.

10 kΩ, 1%, MEASUREMENT SPECIALTIES GAG10K3435A1.
Article No.: NTC 10K 1.0
€1.30

Since there was only one sensor unit available, I had no choice but to drill out the sensor.

Following the motto: Learn by doing.

The cables are embedded within the sensor itself. The colors on the sensor for the thermocouple are green and white. Therefore, I had to carefully remove the potting compound (which appears to be a plastic with fiberglass). I simply drilled small holes and carefully cut away the material with a utility knife.

As far as possible from below, drill a hole through the sensor and solder in the new NTC thermistor.

Resistance was now applied to the corresponding cables.

Now I've glued the new NTC sensor into the previously drilled hole using construction adhesive (PUR). It's quite a messy job and it takes a day to cure.

After that, I sealed the bonded material with Dekaseal 8936. I put everything back together, fixed any errors, took it for a test run, and everything was perfect!

"Working time due to a very, very stuck screw on the mounting bracket of the tank was 10 hours. Without the stuck screw, it would have taken approximately 6 hours. If I have to do it again, it will take about 2 hours."

I hope my construction lasts longer than just from morning until noon.

Thank you all for the great tips, see you soon!

"Or maybe not, see you later... then I'll have something else to fix on the car."

P.S.: I have my own blog, and I will also post my story about the repair there - of course, using similar words. But you are the first to hear it - so don't be surprised .

Here are a few more photos!

Thank you for the feedback.