Fuel Gauge Not Working And Component Protection.

[Jimmy-s3]

hello,
I have a 2015 T6 T28 180BHP DSG..
I have a few issues that need sorting on it, the first is that the fuel gauge doesn’t work. I’ve had the tank off and checked the sender unit (it looked fine) I’ve also tried another sender unit and still didn’t work? Checked the wiring from the tank to the van and all seems ok??

Also the exterior temp gauge shows between -20 and -25? I’ve changed the sensor at the front bumper but it’s not made a difference?

Finally, the standard headunit has component protection activated? I believe it’s the original headunit.. I’ve tried rebooting it by holding the power button but no good?
Any ideas with these faults?
Thanks!

 

[Dellmassive]

Sounds like you need to plug it into a scanner and get some fault codes to proceed.

VCDS or carista would be a start.

 

[Pete C]

Did all those issues appear at about the same time ?

Pete

 

[Jimmy-s3]

I actually bought the van with front end damage.
I had to replace the wiring loom to the headlights as it was cut through, this included the temp sensor?

 

[Dellmassive]

I actually bought the van with front end damage.
I had to replace the wiring loom to the headlights as it was cut through, this included the temp sensor?

a VCDS scan will tell you if you have cut/damaged wires and what the temp sensor is reporting . .. . . if at all.

 

[Jimmy-s3]

Great, I’ll try and find someone with VCDS..
I actually have a Genuine ODIS diagnostic tool but have yet to set it up.¯\_(ツ)_/¯

 

[Pauly]

Make sure the vehicle battery is fully charged, most erroneous CP problems are caused by low voltage

 

[Jimmy-s3]

Had the van connected to ODIS today...
Head unit is faulty, it’s not the component protection that’s switching it on and off continuously.
No fault logged with the temp sensor, I am going to clean the connector terminals tomorrow.

The fuel gauge is showing fault at senor 1?
I’ve tried a new sender unit and still the same, the ODIS also tested the actual fuel dial in the instrument cluster and that works.. so I think it must be a wiring fault..?

 

[Jimmy-s3]

Is there a fuse or relay for the actual sender unit?
I don’t have the owners manual or a fuse box diagram..

 

[Dellmassive]

come and join the VIP club for all the benefits and downloads. (including schematics and fuse box layouts)


VIP Membership | VW T6 Forum - The Dedicated VW Transporter T6 Forum


have a look here > Downloads | VW T6 Forum - The Dedicated VW Transporter T6 Forum


if you cant find what you are looking for . . . . we will get it for you =] (ie diagrams etc)

 

[Jimmy-s3]

How do I access that download?

 

[Loz]

How do I access that download?

You need to be a VIP member

 

[Jimmy-s3]

How do I do that?

 

[Pete C]

Click the VIP membership button at the top of every page.

Pete

 

[Jimmy-s3]

found it!

 

[Jimmy-s3]

So looking at the fuse layouts..
Obviously there is 1 below the gear selector, and is there another in the engine compartment?
I have unplugged the wiring from the in tank sender unit to see if that makes a difference and it didn’t..
The van still runs ok.. so should there be a fuse for that sender ?

 

[Dellmassive]

fuel2 shows the schematic.

the fuel sender unit has 3 wires.

br/ws - brown/white - chassis earth
vi/sw - purple/black - signal to dash panel J285
vi - purple - 5v refernce

you can see that there is a join in the cable under the front seats (T6b - 6pin red connector)

you should be able to test the sender and wire from that point.


the sensor has a ground and 2 wires that run back direct to the front dash clocks via the red connector block under the front seat.

VCDS should give you a fault code relating to a wire short/open etc or a level sensor - out of range etc?

or just test at the red block for the signal and reference voltage . . . . . or shorts/opens.


there is no fuse as such for the sender unit as its fred directly from the dash clocks (which will have a separate fuse)

the fuel lift pump and relay are fused seperately - but thats a different issue, not yours

.

 

[Jimmy-s3]

I don’t seem to have a red block connector under the passenger seat?

 

[Jimmy-s3]

I’ve traced the wiring back from the sender unit and it comes through the floor between the 2 front seats.. and then seems to head towards the centre section of the dash?

 

[Jimmy-s3]

Also, my fuel sender has 5 wires?