Brainfry

Hi all,

See below for the array of Durametric fault codes I've pulled from my '13 991 C4S. Mileage is about 30k. Dash Warnings: 4 Wheel Drive Limited, PSM Loss, Start/Stop deactivated, fault engine control.
This has happened a few times in the past two weeks. They clear when I stop and start up later. But then appear again after I start driving. I cleared all the faults again yesterday, then charged the battery. Got the same codes below... I then disconnected the battery and let it sit. Reconnected
and still had the same faults. I didn't see any P300 codes, but could this still be from bad coils even without a misfire code?

UO418
PO200
P1800
7010
1820
1821
1011
a008
P199A
P1990

Thanks for any help.

asellus

how old is your battery? if over 5 years, consider properly checking its health.

Brainfry

I purchased it with 13k on it two years ago. Haven't changed the battery. Pretty certain its over 5 years... I know they're sensitive to voltage fluctuations, but I haven't seen any significant drops (display voltage readings). And it was fully charged two days ago... that's not to say it's 100% healthy.

barncobob

battery time

Brainfry

Will test it. Resting battery should be 12.4-12.8?

Also, if the battery tests good, could any of those codes indicate a misfire or bad coils?

asellus

Charge it, unhook it, leave it for 8 hours, and measure. You should see 12.6v.

A load test at that point would also be the perfect time to get an actual readout of the health of the battery.

RennListUser01

asellus is dead on ... let it rest after charging and THEN check voltage.

Brainfry

Charged to 100%. Didn't remove it. Let sit for 8 hours. 12.4 at the battery with tester. 12.1 on the dash gauge (car on, engine not running- not sure how accurate). Currently 12.4 at battery with tester.

Next step is coils and plugs.

Thoughts?

RennListUser01

All,

Been watching reviews of various battery load testers ... most measured normal voltage during the test, but responded poorly to the load component of the test. How big is this factor with Porsche systems?

asellus

Sounds like your battery isn't doing too hot. Either that, or you have a pretty substantial parasitic drain -- leaving it hooked up kind of muddies that a bit. What's the date stamp?

Coils and plugs sounds like blindly throwing parts at a problem you haven't diagnosed. Think about it: how would a malfunctioning coil pack or spark plug not cause a misfire code, but also be bad enough to somehow impact your AWD and stability control?

The faults listed on the MFD are all electronic. AWD is controlled via mag clutch. PSM is actuating a high current pump. Start/stop requires battery power to start the car.

I'm guessing you have an original battery. 9-10 years is a good life for an AGM in a modern car.

Brainfry

I completely agree... not seeing any P300 codes was a head scratcher for me... I brought it to the dealer, they read the faults, think the battery is "fine" (I don't believe they tested it) and without a P300 code, that it's STILL coils...

Here's the response: "It has cylinder shutdown codes that refer to the coils, we’ve got those fancy overpriced scan tools just for that." ALSO, their report mentioned "Multiple misfires" however, never stated which cylinders... and recommended I just replace ALL the coils at the same time.

​​​​I'd rather throw a new battery at it than coils and plugs at the moment.

Battery has no date on it. It's a Banner: 12V 70Ah 760A EN. OEM. Additional tester readings: 12.41v, CA/MCA 627. OK/Recharge. SOC 100% 4.54 møhms. SOH 82%.

Brainfry

Also, to compound the issue, I don't get the faults in normal mode. Just sport mode. As for the parasitic drain... I haven't changed or added anything to the system recently that would account for the drain... unless something else is draining it suddenly.

Brainfry

Correction: Dealer stated, "31133 VEHICLE HAS MULTIPLE COIL SHUTDOWN CODES."

Brainfry

Got a proper battery tester. Tested it properly. It failed. I put a new Interstate in this morning. Test drove it for an hour. Not a single fault code, not a single problem.
Never trust a dealer. Their deceitful practices are beyond shameful. So glad I declined their bull**** fraught services.

Thank you my forum friends for your help, guidance and wisdom.

B

RennListUser01

Brainfry,

So, let's go over what, exactly you tested - it apparently passed the voltage part, right? Which tester did you use and what portion of the test failed?