atilla91

As follow-up, I changed all 6x coils and spark plugs, and car works fine, no more faults. I cleared memory with Durametric. A couple months ago I started noticing a bit of engine vibration at idle, and that is gone also.

Loren, thanks for the ideas. I cleared faults, drove fine for 1 trip, then all the faults a few hours later returning. I replaced the original MollAGM (7 years old) in September 2017 with a BoschAGM (pictures). Should I buy one from Porsche at $500? The voltage displayed is 14.3 or 14.4V. I could put an oscope on the 12V and look for noise or V-drop, but not specific gravity. The faults don't come on when starting the engine, rather shortly after starting to drive. I could put a little heater in the battery compartment to see if temp changes anything (just an idea). David

Check engine/PDK/PSM etc faults light up on dash, and Pana goes into limp mode. Happened a week ago, I restarted and it went away. Then twice yesterday. I attached the Durametric. 80K miles now, new plugs from Porsche at 50K, brake pedal sensor at 64K, but otherwise original parts. Any thoughts on what to try? 15 7 Jan 2018 Engine check etc.pdf15 7 Jan 2018 Engine check etc.pdf15 7 Jan 2018 Engine check etc.pdf Engine Module Siemens EMS SDI 6.1 P0500: Ignition Coil "B" Secondary Circuit Upper limit value exceeded C1200: Ignition Coil B Primary/secondary Circuit No signal/communication B0300: Transmission Mount Valve -1-/-2- -N262-/-N263- Short circuit to B+ Value below lower limit value P0200: Cyl.2 Misfire Detected Upper limit value exceeded It is probably unrelated, but a month ago it started giving an error on right side turn signals (and clicking faster), but all the lights are working fine, so I ignored it.

2011 Pana4 with 70K. Any advice on when to replace Serpentine belt? Dealer and service guide gave no hard time nor mileage, rather only by inspection. Is this right, and what are the signs that it should be replaced? It does not look hard to replace, is it? Does anyone know of a tutorial or have any cautions? I do brakes and plugs and filters and fluids myself, but not a mechanic. I read the Forum entry for other Porsche serpentines, but never sure if those comments apply to 970. Thanks, David

As follow up, Dealer reported that they replaced the Brake Light Switch. All faults above were cleared (except the seemingly always on HVAC one). It has not run long enough to be sure the "PSM failure" is gone. Brake Light switch was one of the indicated faults, but it does seem like a lot of other faults for just that. I guess I have to wait and see what happens next.

2011 Pana4 64K. I bought 2 years ago, still under CPO. Everything works as far as I can tell, incl PSM. Starting a few months ago, every couple weeks, “PSM failure” pops up while driving normally (see pix). Then PSM, Autostop/start, and Sport mode are all disabled. Re-start the car, all working again. After clearing all faults, Duramatic shows PDK (U0418) and HVAC (3277300/3201f4) faults, seem always on. Then no more faults until the "PSM failure", when Duramatic shows 5 faults all at once: >engine (B0300) - trans mount valve -1-/-2- -N262-/-N263- short circ to B+ >PSM (17216/4340) - brake light switch implausible >PSM (12656801/c120a1) - Center diff lock control unit fault memory content >PSM (8325/2085)- Sport mode center diff lock, faulty >PSM (8330/208a) - Sport mode, faulty. I clear all 5 and they do not come back until another "PSM failure". I need to see dealer for PDK oil change shortly, so looking for any advice on a fix prior to seeing. Maybe unrelated observations: 1)PSM failure seems to happen more when I have a passenger. Always on freeway. 2)sometimes 3 days, sometimes 3 weeks. Maybe more often 10mins into trip, but some earlier and one at an hour. 3)sometimes in Duramatic I see about 90 faults on Seat Electronics Passenger for "implausible signal" 4)occasionally see CAN Gateway and Electronic parking brake fault with same (3277300/3201f4) as HVAC always has. 5)I changed oil, flushed PS fluid, brake fluid in December. Changed rear pads/sensors last month. All dealer parts/fluids.