Fuel Sender Unit

[rrowles2000]

I have identified that the car I bought came with the wrong sender (I think). It's a 03 A2 1.4tdi.

Resistance is 280 full, and 55 low or empty. I'm assuming this is the B variant, and I need the F variant? Full guage reads empty all the time.

Any thoughts?

Anyone fancy doing a swap?

TIA
Rich

 

[2work]

I have identified that the car I bought came with the wrong sender (I think). It's a 03 A2 1.4tdi.

Resistance is 280 full, and 55 low or empty. I'm assuming this is the B variant, and I need the F variant? Full guage reads empty all the time.

Any thoughts?

Anyone fancy doing a swap?

TIA
Rich

Afternoon Rich,

This does sound like a symptom of having either the incorrect fuel sender fitted or an incorrect revision instrument cluster fitted at some point.

It’s worth adding some more information here to assist us advise. Please obtain the instrument cluster full part number along with the fuel sender part number. Both easy enough to get, one with VCDS and the other by removing the rear right seat and lifting the carpet followed by removing the large fuel sender cap. Expect to not be able to see the part number until it’s had a clean up with a paint brush or similar.

I’d wager that a replacement instrument cluster has been fitted at some point which is the wrong revision. That said the fuel gauge could also be at fault. Before we go down many rabbit holes guessing, let’s have the part numbers involved to rule out incorrect revision items installed.

Kind regards,

Tom

 

[rrowles2000]

Afternoon Rich,

This does sound like a symptom of having either the incorrect fuel sender fitted or an incorrect revision instrument cluster fitted at some point.

It’s worth adding some more information here to assist us advise. Please obtain the instrument cluster full part number along with the fuel sender part number. Both easy enough to get, one with VCDS and the other by removing the rear right seat and lifting the carpet followed by removing the large fuel sender cap. Expect to not be able to see the part number until it’s had a clean up with a paint brush or similar.

I’d wager that a replacement instrument cluster has been fitted at some point which is the wrong revision. That said the fuel gauge could also be at fault. Before we go down many rabbit holes guessing, let’s have the part numbers involved to rule out incorrect revision items installed.

Kind regards,

Tom

Yep number on top of fuel sender ends in B. VCDS? Is that software?

 

[2work]

VCDS? Is that software?

Hi Rich,

Yes it is.

I just assumed you had a diagnostic setup to quickly get the fuel sender resistances mentioned earlier.

If you don’t have VCDS (VAG-Com) then you’ll need to either find someone who does to get the part number or remove the instrument cluster to hopefully see an intact part number sticker.

Kind regards,

Tom

 

[rrowles2000]

Ahh right electronics background so that was easy lol. Fixed bent contact springs to get right resistances with a voltmeter. So I can't just use a standard diag tool a pal has a T4 or T5 setup in his workshop will that work?

 

[2work]

Ahh right electronics background so that was easy lol. Fixed bent contact springs to get right resistances with a voltmeter. So I can't just use a standard diag tool a pal has a T4 or T5 setup in his workshop will that work?

Hi Rich,

That could be entirely possible but I honestly don’t know as don’t know the capabilities of the friends diagnostic equipment. I’ve only ever used VCDS.

Kind regards,

Tom

 

[PlasticMac]

Hi Rich,

That could be entirely possible but I honestly don’t know as don’t know the capabilities of the friends diagnostic equipment. I’ve only ever used VCDS.

Kind regards,

Tom

If you're stuck, I'm near Junction 5 of the M3, and have VCDS.
Mac.

 

[audifan]

Curious does the gauge move when you use fuel or is it always sat at one extreme.
Please clarify your statement...
Full guage reads empty all the time.
If the gauge never rises above empty then it could be the gauge stepper motor that has failed.

 

[Ami]

If you're stuck, I'm near Junction 5 of the M3, and have VCDS.
Mac.

And very good at it I may add

 

[2work]

Curious does the gauge move when you use fuel or is it always sat at one extreme.
Please clarify your statement...
Full guage reads empty all the time.
If the gauge never rises above empty then it could be the gauge stepper motor that has failed.

Evening Graham,

You’re probably right but without VCDS an output test of the cluster might not be possible straight away. Let’s start with the part number to rule Rich’s initial thoughts of incompatible parts then take it from there.

I beleive that other Tom might well be visiting Rich in the next month or 2 who could easily add a new stepper motor if necessary, it’s only 4 pins and well within his ability. If he cannot wait that long then a replacement cluster might just be easier if Mac has the ability to extract the SKC and then match it to the ECU.

Mac @PlasticMac: Happy to assist over PM if you’re not familiar with the process.

Kind regards,

Tom

 

[PlasticMac]

Evening Graham,

You’re probably right but without VCDS an output test of the cluster might not be possible straight away. Let’s start with the part number to rule Rich’s initial thoughts of incompatible parts then take it from there.

I beleive that other Tom might well be visiting Rich in the next month or 2 who could easily add a new stepper motor if necessary, it’s only 4 pins and well within his ability. If he cannot wait that long then a replacement cluster might just be easier if Mac has the ability to extract the SKC and then match it to the ECU.

Mac @PlasticMac: Happy to assist over PM if you’re not familiar with the process.

Kind regards,

Tom

I've never needed to extract an SKC. I've considered installing VAGTacho, but all the download sites look a tad suspicious, so not progressed it. Is VAGTacho the way to go? And, is there a safe way to down a copy?
Mac.

 

[2work]

I've never needed to extract an SKC. I've considered installing VAGTacho, but all the download sites look a tad suspicious, so not progressed it. Is VAGTacho the way to go? And, is there a safe way to down a copy?
Mac.

Morning Mac,

PM on the way Sir.

Kind regards,

Tom

 

[timmus]

I have identified that the car I bought came with the wrong sender (I think). It's a 03 A2 1.4tdi.

Resistance is 280 full, and 55 low or empty. I'm assuming this is the B variant, and I need the F variant? Full guage reads empty all the time.

Any thoughts?

Anyone fancy doing a swap?

TIA
Rich

Hi Rich,

The resistance data that you've posted is correct for the earlier fuel level sensor. Given that you have a 2003 TDI, which almost certainly has the later 42-litre fuel tank and therefore left the factory with the later fuel level sensor, I'd suggest that the incorrect fuel level sensor has been installed in the tank by a previous owner.
However, I cannot be 100% certain that something else isn't amiss (such as a faulty gauge). If you're able to live with the issue until October, then I shall gladly investigate in person when I programme your additional key (as discussed in your other current thread).

All the best,

Tom