Tuesday, January 31, 2012

VW Phaeton fault codes that show up when the car is fine*

*The Phaeton has been running flawlessly.  Every feature works, with the exception of the tire pressure monitoring system (TPMS).  The flat tire light is on constantly, despite the fact that all the tires are properly inflated. I've been told by Phaeton owners both before and after my purchase to ignore this common problem.  Even after shelling out $1,300 to repair the problem, there is a high likelihood that the light would erroneously come back on.

Today, I had the Phaeton's oil changed and tires rotated.  The local independent was kind enough to plug in the diagnostic tool and print out for me the readout.  Here are the findings.  Again, I have noticed zero faults with the car, with the exception of the TPMS.

The following systems had no fault codes:

  • Engine
  • Transmission
  • ABS brakes
  • Locking and starting system
  • Seat memory- passenger
  • HVAC
  • Airbags
  • Steering wheel
  • Instruments
  • CAN gateway
  • Left light
  • Level control
  • Seat memory- driver
  • Navigation
  • Right light
  • Central convenience
  • Sound system
  • Wipers
  • Battery charger
  • Telematics
Here are the parts that contained fault codes:
  • Control head: supply voltage terminal, lower limit exceeded intermittently
  • Central electrical: intervention load management
  • Sunroof: signal to sunroof, intermittent motor for wind deflector, sunroof shade motor
  • TPMS: no signal and initialization not successful

I suspect that new batteries will correct some of the faults.  Am also considering paying $75 to have the TPMS warning light turned off.


Edvin said...

In my experience, that's the way it is with modern cars. There are almost always a number of fault codes stored, even if you never notice anything wrong. It can be something as simple as disconnecting an electrical plug with the ignition on, a slightly longer start-up than usual etc... It doesn't matter if it's only for a fraction of a second, it'll still register. As long as you know what they are and what causes them, it's nothing to worry about (unless you're prone to OCD). :)

My half year old VW has a bunch of codes already, about ten or so, but most of them due to something I've done (navigation & bluetooth retrofit etc). It even had a few codes brand new from the factory.

kashgar216 said...

@Edvin: With my BMW and Acura, I never once thought to check what the code faults were. I blame reading VW Vortex for my curiosity.

kashgar216 said...

@Edvin: In your photo, you look like a young Eddie Vedder.

steve-vh said...

TPMS is a common issue. Lots of guys on the Hummer board i read have issues. there's all sorts of things that can cause it, most likely is that the sending unit batteries need replacing after several years. Mine started going off frequently after startup and then would go off after 10 minutes. Usually means the air temp is low and until the tires heat up from driving, it will show low. Got new tires (and stems) recently and codes went away for a month. Just now started again. I'm thinking it's the spart (which was originaly a main wheel).
The threshold setting for low pressure is determined and programmed in by the manufacturer but lots of guys with hummers like to do different things with tire pressure so.....plus not fact spec tires have different pressure ratings, ect that don't jive with the computer settings.
My understanding is a good tech can override and reset the low setting.

kashgar216 said...

@steve: Thanks for your thoughts. BTW, where do Hummer owners go for recall repairs? GMC? Chevy?

Edvin said...

Ignorance is bliss..

Thanks, I guess. :)

steve-vh said...

The dealer i purchase from is also a caddilac dealer. So as a GM product i go there but I can go to any GM dealer I suppose.
I've only had one recall on it and that's been an advisement of a possible brakefitting issue in the midwest. Did have issues with a trailer harness shorting out that blew the BMS and cost$500 but surprisingly no recall on that....
Been a fabulously trouble free vehicle

Lukas said...

"you've got systems in places where my car doesn't even have places".

$75? Can you not just use black electrical tape?

Also, what's a CAN gateway - fancy term for cup holder?

I'll be quiet now.

m4ff3w said...

What's the air pressure of your spare tire? Is it properly inflated?

kashgar216 said...

m4: Yes. The pressure was the first thing I checked.

Funny story. When I was at the gas station checking my pressure, a nice middle aged Ethiopian/Eritrean lady in an old Maxima pulled up. She asked me if I could check her pressure. I happily complied. The tires ranged from 14 psi to 40 psi. WTF!

kashgar216 said...

@Lukas: I was contemplating the black electrical tape, but I didn't want glue on the precious instrument cluster glass.

As for the CAN Gateway, I had to look that up too. It's some kind of router that connects the computer to the scan tool, I think.

I'm in my 30s and I still remember high school auto shop class and learning about carbs. We've come a long way.

Anonymous said...

$390 will get you 4 German-made sensors and valve kits for Phaeton. These are made by the same manufacturer who built the original VW/Audi sensors installed at the factory.

The Tire Rack. Available over the telephone only, not listed on the website.