Fuel Tank Vent Valve: Professional Quality

Folgende Lage: Ich habe einen V6 TDI, AFB in ein Boot gebaut. Für die Wegfahrsperre wurde die Platine vom T4 genommen. Ich habe also kein Kombiinstrument und keinen Schlüssel mit Lesespule. DThe engine is running!

Just one more problem: The preheating light is still blinking, and it's due to this error:
01440 Fuel level sensor: Open circuit/short circuit to positive.
The fuel level signal from the sensor goes directly to the instrument cluster for the fuel gauge display.
However, in the self-study program for the V6 TDI (specifically, in the overview of the engine control unit's connections), the additional signal for the fuel level is directly connected to the control unit (M). Unfortunately, without specifying the wire color or the connector pin number. I have already searched through several wiring diagrams for TDIs – without success. None of them contain this information.
Could it be that the engine control unit receives this signal, just like the speed signal for the cruise control, via the K-line? I can't explain it any other way...
If that were really the case, I'm sure it can't be simulated, and I'll just have to live with it, right?

Fuel starvation sensor G210.

Connect according to the wiring diagram to the EDC T40/5 and T40/15.

The wire colors are yellow/purple and white/green, referring to the Passat model manufactured from May 1999 onwards, specifically for the AFB engine.

'That's not the G210! It's located in the fuel pump housing! I simulated it using a potentiometer (430 ohms = full). What I need is the fuel level sensor (G). The cable goes to the instrument cluster (sw/li).'

G210 is a SWITCH. Have you ever shorted both pins together?

The fuel level sensor (G) is only connected to the combination instrument and has nothing to do with the EDC system.

Der Fehler mit dem G210 (Fehlercode: 1441: Geber für Kraftstoffmangel G210 Unterbrechung/Kurzschluß nach Plus) ist auch aufgetreten, als ich den Widerstand noch nicht drin hatte. DHe's gone now.
'That's what the repair manual says.'

Check fuel starvation sensor (G210):

- Fuel level in the surge tank: OK.
Set point approximately 430 °C.
- Fuel level in the surge tank is too low:
Set point approximately 100 °C.
If the measured value is 0 or infinity (∞), there is either a broken wire in the tank or a short circuit.

According to this, it cannot be a simple switch. However, the symbol looks like a switch. (Two resistors in series, one of which has a switch in parallel - this is how it is depicted in the SSP). In the circuit diagram, only one switch is shown.

As mentioned before: 1440: Fuel level sensor - interruption/short circuit to positive.

After the error message appears, a cable doesn't necessarily have to be disconnected, or am I mistaken?
'For troubleshooting, the repair manual states the following:'
- Check the fuel level indicator.
=> Folder: Wiring diagrams, electrical troubleshooting, and installation locations.

There's only one guide: Check the sender for the fuel level indicator. And that's the normal fuel tank sender.

What now?

What is the year of manufacture and which vehicle is your AFB engine from?

It is possible that a dedicated line leads to the master device, or that the signal is transmitted via CAN.
It depends on the vehicle and model year.

greetings
edz

So, here's the thing:
Let's assume, for the sake of argument, that there is no CAN (Controller Area Network) bus.

The fuel warning light connection is located at connector 2, pin 17, in AUDI vehicles.
Wire color: black/purple, located at the engine control unit. ## Applicable to models up to and including the 1999 model year. ##


At VW, pin 26 on the T40 connector.
Cable color: black/purple. ## Until May 1999. ##


It works something like this:
If the 'fuel dispenser' symbol illuminates on the control panel (indicating the reserve light is on).
The fuel level sensor signal is sent to the engine control unit.
In the engine control unit (ECU), the fuel level signal and the fuel low sensor (G210) are processed.
translated. The purpose of the action was to prevent the vehicle from being 'drained' (i.e., completely emptied of its resources).

The level of this signal needs to be measured, or it needs to be determined whether it's a PWM signal. In any case, the pin must always have a certain voltage level; otherwise, the MSG diagnostic system wouldn't be able to recognize it. Setting the pin to 2 volts or ground won't help. (A fault – either an open circuit/short circuit to 2 volts or a short circuit to ground – will be stored, as expected.)

Best regards,
edz

The CAN bus is 'not' present. This means that control units for ABS, automatic transmission, and the instrument cluster are obviously missing. These errors are displayed, but are not of further concern. The engine comes from a Passat, and the year of manufacture should be 1999. However, I cannot be certain about this, as there was no vehicle or documentation available. Based on the pin configuration of the control unit, this should be correct.

'So, it seems my initial assumption wasn't that far off. I've now found the wiring diagram showing the connection from the control unit to the instrument cluster. I was always looking in the electrical diagrams from May 1999 onwards, but nothing is indicated there (the sw/li cable ends at the connector). Therefore, only vehicles produced from August 1998 to May 1999 have the warning light connection.'
Perhaps it's enough to connect a diode (or a light bulb?) to the cable and connect it to ground or positive. Nothing should happen to the diode, right? I'll check that. It worked for the brake light switch - I connected the brake lights and the error disappeared!
It would be great if someone could measure the signal. Unfortunately, I don't have the means to do so. On the AI board, it would be pin 10 on the green 32x connector.

Hi, I'm having the exact same problem!

Have you already performed an Ohms test on the middle pins of the 4-pin connector?

Tank empty. Target value: approximately 341 - 360 Ohms.

Tank 8l, approximately 286-334 Ohms.

Fuel tank full: 59-78 Ohms.

With my car, the sender had a resistance of around 250 ohms when the tank was full, so the gauge started blinking when the tank was about half full. After that, the fuel level sensor disables the ESP to prevent the ESP from shutting down.
I'm going to solder a 60-ohm resistor into the cable tomorrow; hopefully, that will fix the problem.

Best regards, Chris.