Hank Cohn

@ZedZed , thanks for your answers! I’ve now read through the manual in @andy2111 ’s signature—appreciate you pointing that out. It seems like I’m at a similar crossroads as you once were, deciding between PCM modification and other options. I’m not too concerned about the minor surgery on the PCM, as I’ve done that kind of work plenty of times. Sounds like we have similar IT backgrounds—I’ve got a box full of old PC, laptop, and phone parts too!

Since price isn’t a major concern, I think I’ll go ahead and pick up a Chstek to see how it works out. It seems like an easier and more cost-effective route to try first.

Thank you agin,
Hank

mac_flyer9

I just applied the bright fix. I was in the car for 20 mins after applying it with the unit constantly restarting.....I was thinking "damn, i bricked it" Turns out, I needed a full restart. So I pulled the PCM fuse and the cold restart fixed it. I'll report back on the illumination when I get a chance to see it. I'll also comment when I get the new Sport Chrono gauge and new TPMS sensors. Appreciate the help. Thank you

ZedZed

I may be able to shed some light on this, having fitted a chrono clock to a Porsche that did not have one as OEM. First, the time on the chrono clock takes its time from the time displayed in the dash display to the right of the cluster. It has no relationship to the PCM. When I installed the chrono clock, as soon as I hooked up the clock wires, it synched with the dash clock. You can prove this by removing the PCM entirely and observing that the clock in the instrument cluster still operates as normal. The clock in the cluster takes its signal from one small wire in the loom inside the multi-stalk unit mounted to the clockspring/steering column. So even if you have no PCM at all, let alone a CHSTEK replacement for it, the times on the chrono clock and the dash clock should be the same. That they are not in your car suggests an issue with the chrono clock, or maybe not, but it won't be down to the removal of the PCM. Also, of course, the chrono itself is not dependent on the original PCM - again this is evident from the fact that the chrono function still works after the PCM has been removed/replaced.

Again, the PCM doesn't control or impact the TPMS. TPMS settings are done from the multifunctional display (MFD) and, again, the TPMS will function correctly even if the PCM is physically absent. The problem you are experiencing is likely to be either the TPMS sensors themselves (inside the wheels) have failed and/or their batteries have died, or the TPMS control unit itself has failed. This (in my car) was located in one of the rear wheel arches. It is easy to fit a new control unit (two bolts and a wire connector) but the bad news is that the unit then has to be coded to the car by Porsche (or someone with a PIWIS). Swapping the in-wheel sensors is easy enough (although the tyres need to be removed and refitted), but again it is likely that the new sensors may need coding to the car. I am not 100% certain about the last sentence, and it may only be the control unit itself that needs coding.

You may decide that the OEM TPMS is an expensive waste of money, and just install the in-wheel TPMS sensors and USB control box made by Erisin. This will save you a ton of money (no need for PIWIS coding) and also, IMO, the display and functionality of the Erisin TPMS sensors is superior to the OEM Porsche version. Andy @andy2111 (and my wife in her Cayman) run the Erisin TPMS, albeit with the external sensors mounted on the tyre valves, and both of us hold them in high regard. When the time comes to change the tyres on the Cayman, I will be installing the in-wheel Erisin sensors. They work exactly the same way but are obviously a more elegant solution than the external sensors.

Caveat - the info regarding the chrono clock is my experience on my former Panamera, and YMMV on a 911, Cayman, or any other model of Porsche.

Very nice too. Love the color of the car as well.

[/QUOTE]

ZedZed

@mac_flyer9

Is your chrono clock the version with the small analog clock inset into the dial (as opposed to a digital clock)? If so, it is possible that the hands have 'slipped' - they are notorious for actually falling off.
Andy's suggestion is a good one.- go into the MFD and set the time to a random time. The chrono clock should mimic this. If it approximates it, is the difference the same as it was when the dash time was correct? I mean, if it was 2 minutes different before, is it still 2 minutes different now, or something else entirely?

mac_flyer9

The clock has the digital time and small clock underneath it. It displays a different time every time I either program it or I turn on the GPS time and don't think the hands have slipped.
I'm pretty sure its a bad Sport Chrono clock and dead TPMS sensors, as the previous set of wheels/tires read just fine on the MFD.

Thanks for all the information/advice/troubleshooting ideas as they are concise and helpful.

bmxtreme

Can confirm TPMS doesn't need PCM. I swap out my wheels recently and also replace all 4 TPMS and the car registers it. The TPMS control module is a separate box mounted under the car. Love the techno wheels btw.