Sensor mass, shielding, fuel level sensor, Opel Insignia B

I'm having a problem with an Opel Insignia B. The fuel gauge isn't working, and it seems there's a communication problem with the fuel pump control unit.

My question is more general. What's the deal with this bare wire? It's a blue cable where a bare aluminum wire is soldered on, and this is then twisted together with the other three wires and was "insulated" with aluminum tape. I was only surprised that I had continuity from the plug of the blue cable to the aluminum sheathing.

Perhaps you can help me with the image of the circuit diagram.

Bare = naked = without insulation / exposed wire.

In practice, this is the shielding, which is typically implemented exactly as you described. The short, blue-insulated piece is likely only present for manufacturing reasons (to allow for proper crimping within the connector). After that, it continues as bare wire and is connected to the shielding. The shielding is what you refer to as the aluminum tape insulation.
My statements are based on the assumption that the blue wire from the fuel level sensor connects to pin 4 or to pin 23 on the control unit.

However, there is no blue wire shown in your circuit diagram. This is probably just an inaccuracy. It wouldn't be surprising, considering the circuit diagram is questionable anyway. (The wires in the circuit diagram are labeled U/V/W, which is typically used for three-phase power. Furthermore, the pins are shown as being connected to ground. However, I highly doubt this is the case for a pump with an integrated control unit and tank sensor.)
Regards,
Guste.

Hi,

Okay, so the blue wire goes from pin 4 to pin 23. The shielding is soldered on at the beginning, and a heat shrink tube insulates the solder joint. I'll take some pictures this afternoon. I was also puzzled because I wanted to measure continuity at pin 23, and suddenly I had continuity on the aluminum insulation. I unwrapped it because I thought something might have been rubbing against it.

Thank you for the quick response, and best regards.

You're right, it's the shielding. This circuit diagram doesn't make much sense to me...

Okay, so it seems like it's not a major issue that there's a connection to the outside through the aluminum strip, or even that it's intentional.

Here are two more pictures.

I'm afraid that without a proper wiring diagram, troubleshooting will be difficult, unless there's something obvious like chafing or broken cables that can be seen.

Good evening.

The issue with the fuel gauge is not uncommon in the Insignia.

Sometimes, the entire instrument cluster will simply detach.

Do you have the rest of the wiring diagram as well?

The explanation for fuel pump A7 describes the other wire colors, including a testing guide.

Do you have an error code you can share with us? Does the fuel gauge still move after turning the ignition on and off?


Best regards,

Michael.