Welcome to RennTech.org Community, Guest
There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.
Here are some of the features available - once you register at RennTech.org
- View Classified Ads
- DIY Tutorials
- Porsche TSB Listings (limited)
- VIN Decoder
- Special Offers
OBD II P-Codes
- Paint Codes
- Videos System
- View Reviews
- and get rid of this welcome message
It takes just a few minutes to register, and it's FREE
Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)
- No ads - advertisements are removed
- Access the Contributors Only Forum
- Contributing Members Only Downloads
- Send attachments with PMs
- All image/file storage limits are substantially increased for all Contributing Members
- Option Codes Lookup
- VIN Option Lookups (limited)
I changed the headlight switch and brake light switch and neither helped. So I put the original headlight switch back in (wasn't going to pay to keep a light switch that didn't need to be replaced). I gave up and brought it to a shop. They spent hours trying to diagnose things and even called Porsche to get help. They suggested checking out the tail light bulbs. It turned out that a prior owner had installed the wrong tail lamps in back. I guess they used single filament bulbs instead of double filament bulbs. That was shorting out the system and throwing the error codes. Once the right bulbs were put in the car, everything worked perfectly. The headlight switch and brake light switch are common causes, but in my case the problem was harder to find but easier to fix.
Update....one correction to make. My brake lights are actually always ON when the headlights are turned on...but they operate normally when the headlights are off. Battery checked out OK and the voltmeter in the dash reads 14 when the car is running, so I believe the charging system is good. I replaced the headlight switch with a new one from the local Porsche dealer and no change. So I took it back out and returned it. Now waiting for a brake switch to arrive in the mail so I can try that out.
Dealing with this issue on the driver side of my 2004 911 cab. Do you have to pull the seat to get to the relay? I'd like to test that first. Our dash light just barely flickers on, so I'm hoping it's just a bad relay.
I'm having a problem and think the brake switch is at fault...but not sure.I have the ABS/PCM lights showing up on the dash.When the headlights are turned off, my brake lights function normally. I don't get the warning lights when the headlight switch is off. When the headlights are turned on, the brake lights do not turn on and the ABS/PCM warning lights come on. Would a faulty brake switch be the cause of this or could it be something else?
Just found the answer in another post here: Push the computer control lever (lever below turn signal stalk) forward twice. This should get you into the "set" menu. Now push the lever down about 5 times until you see the temperature:celsius/fahrenheit function. Select Celsius and push the lever forward to change. Pull back on the lever several times to back out of the menus
First post...I'm the new owner of a 2004 911 Cab that I bought for my wife. The LED display on the a/c control was cracked, so I bought a used replacement unit and installed it. The new unit has the temp displayed in Celsius and I can't find any instructions in the manual on how to change it to F. The old unit did display in F. Anyone know how to do this?