ManoTexas

After only manuals for decades, PDK was one of preferred options when looking for my 997.2 for various reasons. Last Wed, for the second time in my 5 yrs thought crap, I’ll have to eat my words of praise for how good the PDK is. First time car just ran horrible, lots of warning lights (no transmission light though) etc, but turned out to be HPFP.

Last Wed afternoon flying down the fwy driving normal when Transmission Limp Home Mode Engaged (or similar warning) shows up. Dammit. Exited, pulled into gas station and turned off car hoping random error would clear. Sure enough no code, ran fine so pulled out and got back on fwy. Couple miles later, same message. Thought this is it, please lord just get me home. Went about 3 miles and message turned into Visit Service Center, then car started running rough and shuddering. Made it to exit, turned car off/on at the light, messages gone. Went 200 yds and they lit up again, car running really bad by now. Said fi, just get the 4 miles home, PDK dead and driving won’t kill it any worse. Each mile was more torture, pain, and fear of spending my next 4 dive trips on a f’ing PDK. By time got home car shuddering constantly and xmas tree dash warnings. My heart hurt with pain. Texted my boys their future fight on 911 inheritence looks passe.

Had car towed to shop. They called and said well, your PDK is fine, but getting mis-fire code. Turned out to be bad coil, so they replaced plugs and coils. What a relief!! But also PIA. I’ve maintained car correctly, plugs/coils replaced 4 yrs/22k miles ago. Retiring end of month and was planning on tackling that myself in Nov. Main point is without warning a coil goes bad and you’ll experience what appears to be a death knell in warning lights. I was stunned it caused a transmission error message, and how very poorly the car ran with one bad coil.

Thought I’d have to join the group with PDK failure and admit the manual guys replacing their clutches every so often were right lol. I feel sorry for my boys, they now have to fight over who gets the car. Anyone replacing plugs who looks at coils and goes oh, no cracks I’ll reuse them is making a mistake in mind after this experience YMMV.

Bxstr

Glad that it was just a bad coil. Much better than needing a new PDK. PDK failure is not common, but when it happens, it's expensive.

Wayne Smith

Sounds like one of the coils was arcing to the frame causing voltage spikes. Once these spikes occur sensors will be misread. It's the computers' jobs to take sensors seriously. So you get all kinds of error messages. It's just the way it is with modern cars.

Glad it was a simple diagnosis and fix. Others have had much more trouble diagnosing down to the coil.

BucketList

OK so I had my plugs done at 80K with the rest of the 40K interval stuff about 6k ago. I did not have the coils replaced. How often should that be done? Are they really a high frequency failure item?

Wayne Smith

There have been multiple versions of the coils. They are subject to chemical damage if you live in snow and drive on salted roads. Later coils seem to be much better.

FWIW I'm at 136K miles (2010) and still have the original coils. That's in a moderate climate (San Francisco Bay Area).

ManoTexas

Got my lust back home where she belongs! I live in Fort Worth, not much of a winter here but summers are hot. Who knows if that contributed to coil issue. But glad to be fixed and in 4 yrs replace them all again.

Nein Elf

For what it is worth, I had a coil go bad on my 2009 MB 3.5L V-6 at 100,000 miles. I know that we are in an apples and oranges situation here. I replaced all of the coil packs (and plugs) at that time. That's a DIY on that engine, wish it was easier on the P Flat 6 too. When you replace your plugs again at 120,000 miles I would definitely replace the coil packs too, especially since they have to be removed to change the plugs anyway.

ADias

So here we have again a 'sky is falling' post worrying about the PDK. It's always the PDK, except that it was the HPPF, and then it was a bad coil.

Wouldn't it be more helpful to instead post describing the actual issues and pointing out that often the complex networked system causes all kinds of errors including false errors pointing to other items that actually are not failing?

lexhair

I don't see coil replacement in my 2009 C4S maintenance manual. I'll see what my indy suggests at the 12 year. At $300 for the parts only, I'd rather spend my money on fluids, belts, plugs, oils and filters.

ManoTexas

I posted the issues I had and warning lights incurred. What would you initially think when get transmission error? I also posted the cause and resolution when became known. Sorry you don’t think the post was helpful.

Ironman88

Negative spin in the comment above is unwarranted.

The post was not an over-reaction and was helpful in my opinion.