Go Back   AudiWorld Forums > Audi Models > Audi A8 / S8 > A8 / S8 (D3 Platform) Discussion
Sign in using an external account
Register Forgot Password?


A8 / S8 (D3 Platform) Discussion Discussion forum for the D3 Audi A8 produced from 2003-2010 and Audi S8 produced from 2006-2010

Welcome to AudiWorld Forums!
Welcome to AudiWorld.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the AudiWorld Forums community today!


Reply
 
 
 
 
LinkBack Thread Tools Search this Thread Display Modes
Old 06-28-2014, 01:55 PM   #1
AudiWorld Newcomer
Account #: 284957
 
Join Date: Jun 2014
Posts: 6
Default Faulty fuel gauge audi a8 4.2tdi

Hello,
The following situation occured with my audi a8.

The fuel gauge shows empty, while the tank is full. No fault codes.

I already took the 4 sensors out of the tank, and the resistance of every sensor looks ok. Upper sensors are 70-157ohm. the lower sensors are 50-300ohm.

There are no fault codes. Fuel gauge just shows empty.

When doing the analog test with vcds the fuel gauge meter works.

The car has a diesel engine, but the gasonline version uses the same gauge senders.

Anyone experienced this problem?

Thanks


Click the image to open in full size.
Audi TDI is offline   Reply With Quote
Old 06-30-2014, 07:17 PM   #2
AudiWorld Senior Member
Account #: 176342
 
Brozee's Avatar
 
Join Date: Jan 2010
Location: Michigan
Posts: 1,935
Default

Have the same issue with my 4.2 but it somewhat works. No codes and the sensors all read fine. Now I'm locked out and can't access the instruments section of vcds. I think I have to disconnect the battery to fix it.
__________________
2013 S5
Roc-Euro Intake, Hardwired Escort 9500ix, Tint, H&R Spacers, LED Interior, HID Fogs, RS5 Grill, VCDS Mods

2005 A8 4.2L w/ all packages.
Mods: LED's all around, HOEN fogs, Hardwired Escort 9500ix, limo tint, 2011 Maps, MMI v46.1 VCDS Mods: belt chime delete, remote window control.

Popular Topics & Help for Noobies:
Oil Change Procedure
Disable TPMS System
AMI Installation
AMI Update (Phone not pairing)
Remote Window Control
Enable Hidden Menu & Enable Battery Meter
Fog Light Replacement
City Light Bulb Replacement

Door, Trunk, & Glove Box LED Change
Cabin Air Filter Change
Maintenance & Common Problems
Brozee is offline   Reply With Quote
Old 07-01-2014, 01:18 PM   #3
Audiworld Junior Member
Account #: 255014
 
RenoRanes's Avatar
 
Join Date: Mar 2013
Location: Bristol, UK
Posts: 44
Default

Yes I've had the same thing on my W12, although mine doesn't show empty all the time, it will only show empty if the tank is more than half full, half full and under it reads but is a bit out, I've run out a few times with it showing just above reserve. It's apparently the wiring loom, I've read it somewhere on here that it's basically a bad/broken wire and my garage also did some research and has done another with the same problem. Trouble is replacing the whole loom is a big job, they are seeing if it can be 'fixed' where you don't have to replace the whole loom but just the one wire instead.
RenoRanes is offline   Reply With Quote
Old 07-07-2014, 12:18 PM   #4
AudiWorld Newcomer
Account #: 284957
 
Join Date: Jun 2014
Posts: 6
Default

Thanks for the answers!

Update:
I just checked all sensors again. The lower sensors have a resistance from 50 to 1000 Ohm. I mentioned 50 to 300 Ohm in the first post, but that is not correct. OEM value is 50 to 1000.

I also checked the wires. There are 5 wires that go directly from the cockpit to the sensors. 1 wire is the supply voltage that goes to all sensors. The other 4 wires are the "returning" ones from the fuel sensors to the cockpit. These wires are not open or short to plus. To make sure I made 5 new wires running through the trunk straight to the cockpit. This makes no difference. I strongly suspect the cluster itself. It will be tested this week by a rebuilding company. To be continued...
Audi TDI is offline   Reply With Quote
Old 07-07-2014, 12:23 PM   #5
Senior Member
Account #: 26081
 
Join Date: Oct 2001
Posts: 5,719
Default Thanks for the update here

I don't have anything to add, but appreciate the info. if it ever comes up for me or others. Cluster failure possibility rather than the usual sensors is a new twist.
__________________
Current #1: '06 D3 A8L W12 brilliant black w/ amaretto; 4 seat setup, CPO; modestly lowered, H&R 20mm rear and 12mm front DRs with 275/35 on OEM polished + forged 20's; S8 sway bars (see: rear bar and gen'l D3 bar info and front bar); tweaked 385mm front factory brake mod and matching rear brake mod; matching C6 A6 back headrests (better rear view: headrest tweak); owner installed AMI retrofit with part number details here.
Current #2: 2013 Q5 2.0T hybrid; Scuba blue w/ chestnut sport interior; Euro delivery 7/2013 (pictured at Ingolstadt)
Prior (each modded): 2000 C5 A6 4.2 & '96 C4 A6 2.8Q, both still w/ family; '85 C3 5000S 5 sp FWD; '73 C1 100LS

helpful cross reference to a C6 post with MMI and other TSB's that also cover D3 A8's.

MP4.2+6.0 is offline   Reply With Quote
Old 07-21-2014, 06:56 AM   #6
AudiWorld Newcomer
Account #: 284957
 
Join Date: Jun 2014
Posts: 6
Default

Update:
Instrument cluster was send to two different rebuilders, both were not able to diagnose/test it properly.

I'm now looking for a used one. I assume I have to go to the dealer to have it installed. This is not a VCDS Job. What info do I need from the donor car?

Thanks!
Audi TDI is offline   Reply With Quote
Old 07-21-2014, 07:17 AM   #7
AudiWorld Super User
Account #: 195381
 
mishar's Avatar
 
Join Date: Nov 2010
Location: Vancouver, Canada
Posts: 4,608
Default

Instrument cluster has Component Protection and it has to be removed by a dealer. Problem is with the millage. It can't be adjusted (except if it is a brand new cluster). So donor car must be same as yours and millage on it should be close to your millage. Be aware that it is also recorded in the engine computer, so cheating is not advisable.
mishar is offline   Reply With Quote
Old 08-06-2014, 05:22 AM   #8
AudiWorld Newcomer
Account #: 284957
 
Join Date: Jun 2014
Posts: 6
Default

Update: Prolem solved!!

I replaced the cluster with a good used one and the fuel meter is working again!

Changed the mileage to the current mileage using vag tacho.

I's not neccesary to go to the dealer. There is no immobilizer inside this cluster!
Audi TDI is offline   Reply With Quote
Old 08-06-2014, 06:22 AM   #9
AudiWorld Senior Member
Account #: 176342
 
Brozee's Avatar
 
Join Date: Jan 2010
Location: Michigan
Posts: 1,935
Default

Where did you get the used cluster? My 2005 A8 keeps reporting a low or mid tank when it is full or has more gas than it reports. Same situation as I've last reported. Thing is, the car is locked out of the Instruments section (17). I heard on one obscure post that detaching the battery could reset it and re-enable my access to the car's readings. Anyone hear of this? All other modules work perfect and allow me access in VCDS just not the instruments anymore. Just times out and say's it's unreachable.
__________________
2013 S5
Roc-Euro Intake, Hardwired Escort 9500ix, Tint, H&R Spacers, LED Interior, HID Fogs, RS5 Grill, VCDS Mods

2005 A8 4.2L w/ all packages.
Mods: LED's all around, HOEN fogs, Hardwired Escort 9500ix, limo tint, 2011 Maps, MMI v46.1 VCDS Mods: belt chime delete, remote window control.

Popular Topics & Help for Noobies:
Oil Change Procedure
Disable TPMS System
AMI Installation
AMI Update (Phone not pairing)
Remote Window Control
Enable Hidden Menu & Enable Battery Meter
Fog Light Replacement
City Light Bulb Replacement

Door, Trunk, & Glove Box LED Change
Cabin Air Filter Change
Maintenance & Common Problems
Brozee is offline   Reply With Quote
Old 08-06-2014, 06:49 AM   #10
AudiWorld Super User
Account #: 195381
 
mishar's Avatar
 
Join Date: Nov 2010
Location: Vancouver, Canada
Posts: 4,608
Default

Quote:
Originally Posted by Audi TDI View Post
Update: Prolem solved!!

I replaced the cluster with a good used one and the fuel meter is working again!

Changed the mileage to the current mileage using vag tacho.

I's not neccesary to go to the dealer. There is no immobilizer inside this cluster!
What version of Vag Tacho? Do you have it?

Last edited by mishar; 08-06-2014 at 06:48 PM.
mishar is offline   Reply With Quote
Old 08-06-2014, 06:49 AM
AudiWorld
Audi R8




Paid Advertisement
 
 
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 03:45 PM.


Copyright 2014 AudiWorld.com Audi Enthusiast Community