[deilenberger]

Great diagnostics techniques. About as good as I've seen, you've isolated it to one device. My WAG is - hooking up a Porsche-specific device to the diagnostics port might tell more as to what's happening in the instrument cluster. It's either that or a new (used maybe) instrument cluster. The reason for the "maybe" is - it's not clear to me how to get a used cluster's displayed mileage to match your old cluster. I believe the mileage can be changed as long as you're going forward (higher) with it. The Foxwell NT530 does have a section on mileage adjustment, but it's a function I haven't needed to use, and I am reluctant to use since it probably only can advance my mileage.

A rather obvious first step might be to remove the cluster and make sure all the connectors going to it are fully seated and clean. Chances are they are (they generally use locking latch-type connectors that are unlikely to come loose) but it wouldn't cost anything to try.

 

[deilenberger]

Please let us know what the outcome of the dealer visit is..

 

[deilenberger]

And the cluster "BRAKE" warning lights up at the same time. Wow. Does the iCarSoft scanner allow you to look at inputs to the instrument cluster? And it might be worthwhile getting a subscription to AllDataDIY - they should have the wiring diagrams, which would help figure out what all the different circuits have in common. There is a discount code for AllData, if you decide to get a subscription, ping me first and I'll pass it along.

 

[deilenberger]

Interesting - steering column seems unlikely. The instrument cluster maybe, and what the heck IS the stop-switch, and it's certainly not a one-wire circuit, there has to be another wire coming out the other side of the switch. Might it be the brake light switch? Dunno if the 911 has it - but lots of Porsches have two brake light switches. One checks up on the other one. See if there is any reference to it on the component locator.

BTW - I have similar PDF manuals for my Cayenne and Boxster. I find them almost worthless since they repeat details for EVERY variant of a model that they cover. 911S is different from a 911GTS, so we have repeated sections - identical repeated sections for each of them. It makes finding things very slow and frustrating. What AllData has done is distilled that 6,000+ page manual (the Cayenne one is over 11,000 pages) down to JUST the information for the model you subscribed to. It includes the manual section numbers, so if I need to see the factory layout/details - I can then search the 11,000 pages for the section ID, and it goes right to it.

 

[deilenberger]

The diagram shows B9 going also to the stop light switch. Could the brake pedal switch be misadjusted and is actually making occasional contact? That SHOULD turn the brake lights on, of course. I can't think of anything inside the cluster that could command a relay to turn on, but obviously the stop light switch can do that.

It's not clear that it actually is the stop light switch. It's labeled "stop switch" - it probably is worth searching other diagrams to see if the switch can be ID's and see where the output wiring from that switch goes/connects to.

 

[deilenberger]

I suspect your car is sitting out behind the shop getting the sunshine treatment. It's possible the current dealer has tried to get the Porsche Cars NA technical guy to come to take a look at it. If he hasn't tried to get him in - you should ask them why not.

This is the scary thing about these cars - the mechanics are rarely decent at troubleshooting electronic issues, and as the electronics gets more complex - the need for competent troubleshooting will only grow. Porsche tries to solve this with PIWIS - all the dealer should have to do is hook it up and be told what to replace. The thing is - PIWIS isn't that smart and never will be - it still will require a functioning human brain to do an adequate and accurate diagnosis.

Your 981 electronics are contemporary with my Cayenne electronics, and I've had more issues with electronics on that car then about any car I've ever owned... and they're never simple - they all have been head-scratching sort of problems. Right now I'm fighting KESSY - doesn't see my key, steering-lock doesn't think it's disengaged, sometimes a door handle lock button works, othertimes not - and it's a brand new handle.

Due to the difficulty of accurately diagnosing issues - I end up doing something I absolutely HATE to do - diagnosis by component replacement. It's costly, wasteful, and just pisses me off.

 

[deilenberger]

Here’s another idea: if you or the dealer can find another car with similar electronics, then swapping parts becomes a possibility. For example, swapping out the instrument cluster between the two cars.

Yes and no. It might resolve if the cluster is causing the clicking relays - but it might also cause another issue.

The instrument cluster isn't the only place the car's mileage is recorded, and if you plug in an instrument cluster with less miles on it than the old cluster had - the discrepancy will be noted by the secondary storage point. On BMW's doing this will set an error dot in the odometer window, so anyone in the know realizes there is a potential mileage discrepancy. If you install a new cluster - it obviously has fewer miles on it than the stored mileage so it has to be set to the mileage stored in the secondary storage device. This might (don't swear to it, but I'm sure the mechanics know or can ask) not be an issue if a higher mileage cluster is installed.

There is a function in the Foxwell NT530 for "odometer correction" which I believe syncs the replacement cluster to the stored data. I don't know if this only works if the replacement odometer has fewer miles on it or not - something to check before trying that for troubleshooting.

And that's not to say that it's impossible to set back odometers on digital cars.. according to a mechanic friend it's done all the time, and I've certainly seen devices sold on "diagnostics" websites that claim to do it.

Here are the instructions for a 2011 Cayenne - the 981 should be similar:

Information
If the instrument cluster is replaced, the fuel-level sensors must be calibrated using PIWIS Tester II 9818 .

• To calibrate the fuel-level sensors, the fuel tank must be drained completely.

1. Connect the Porsche System Tester to the vehicle and start the System Tester. Switch on ignition.
2. Select vehicle type.
3. Select the required control unit Instrument cluster in the overview .
4. Select Maintenance/repairs .
5. Select Control unit replacement and press F12.
6. Select Read data and press F12.
7. Press F8 to start reading out data.
8. Check the chassis number and press F12.
9. Document the total distance.
10. Switch off ignition and replace control unit. See: 902519 Removing and installing instrument cluster.
11. Switch on ignition and select Instrument cluster control unit.
12. Select Maintenance/repairs menu, Control unit replacement and Write data , then press F12 and press F8 to start. The data that was read out is installed.
13. The System Tester displays the message Data has been written . Press F12 to continue.
14. Select the Set total mileage function and press F12.
15. Select the total distance and enter the correct mileage (value from the "old" instrument cluster). Then press "Enter" to confirm your entry and press F8 to write data.
16. Follow the instructions on the Tester and press F8 to start the process.
17. Select the Calibrate fuel-level sensor function and press F12.
18. Follow the instruction on the Tester. Press F12. Tank must be completely empty. See: Powertrain Management\Fuel Delivery and Air Induction\Fuel Tank\Service and Repair\Procedures
19. Calibrate fuel-level sensors in accordance with the instructions on the Tester.
20. Read out the fault memory and erase it if necessary.
21. Return to the overview of control units.
22. Check the function of the instrument cluster and fuel level gauge during the test drive.

 

[deilenberger]

Sheeze.. this is making CPO seem worthless (are you listening PC-North America? This IS getting exposure..)

You seem to be stuck between 2 sleazy dealers. The selling dealer who did not do the CPO qualification correctly, and the dealer you're now using who is trying to push what should be covered by CPO off on you, due to a claim that the former owner - at THIER FRIGGIN' DEALERSHIP - neglected service.

I seem to remember the selling dealer gave you a refund of $2,000 at one point? I wonder if they thought that should exonerate them in honoring the CPO warranty (which costs them around $2,000 with Porsche Cars NA.)?

What to do? I'd be all over PC-NA at this point. It shouldn't be up to the customer to try to resolve CPO responsibility. And again - I'd suggest written letters, one to the customer relations department with a copy also sent to the President of Porsche Cars North America (he likely won't read it, but someone with some clout will..)

Points to make with PC-NA:

- This is being discussed on a national forum with over 65,000 members.. and it doesn't reflect well on Porsche CPO, so the use of CPO as a sales tool is likely to become ineffective.

- Where in the terms of the CPO contract with you does it state Porsche won't cover failures due to neglect on the part of a former owner? And do they REALLY want it known that's the policy?

- Based on their advertising and your perceived expectation of excellence, you were coaxed to buy a used Porsche from a Porsche dealer due to the availability of the CPO warranty. Your disappointment in your treatment is profound.

DO NOT tell them you'll never buy another Porsche. Any warranty is looked at as a sales tool. It's also billed toward advertising. If sales are slow, warranties get better in the hope of getting customers in to buy something (KIA, Hyundai - 10-year warranty, that got them a foot into the US marketplace. I expect to see it disappear once they really gain some market share in the US.) Telling them you'll never buy another Porsche leaves them little incentive to try to make you happy. DO express how surprised you are at receiving the treatment you've been receiving.

In the majority of cases - Porsche will repay a dealership for almost anything they offer to cover for the customer under CPO. The exception to that is when a dealership is being watched by the national organization because of excessive warranty claims (sometimes entirely bogus claims meant just to milk money from the mothership.) If the dealer is under watch you can be certain they'll be stingy with warranty coverage. That's undoubtedly why some dealerships will warranty warping door cards, and crazing headlights under CPO while others deny it. Just the fear of being put under watch probably promotes that sort of behavior.

Next steps - if contacting PC-NA doesn't work.. you want to brighten the spotlight on the issue..

• Post about it in any Porsche-related forum you can find.
• Post it on Porsche's Facebook page (Porsche - is the international page, it will get seen in Germany. They undoubtedly moderate posts to their page, but your's will be seen and likely passed on to management).

Good luck, I'm sure you'll let us know how this gets resolved.

 

[deilenberger]

I'm closing this thread, and copying the latest comments over to the CPO thread where this discussion can be continued. It's less of a mystery of what the issue is - sounds like the selling dealer knew what it was from the get-go. It's more an issue now of getting this fixed - and covered - under the CPO warranty.

The CPO thread can be found at: CPO purchase experience. The Good, Bad, and the Ugly...