Zero fault code reporting in limp mode, why?

[RandallF]

I have been contacted seeking comment on zero fault code reporting on a 2024 Panamera going into limp mode. I would point out the car is presently with her Porsche dealership for further investigation, and a ticket raised, but is seeking comment and to ask if anyone else has had similar problems:

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Hello Randall,

Many thanks for speaking with me this morning.

I bought a 2024 hybrid Panamera in March 2024. The car was 5 months old with approximately 8000 miles on the clock. The car was purchased from a Porsche dealership in Kent.

In July of 2024, I started the car up on the drive and several warning lights appeared on the dash and the vehicle was un-drivable due to having gone into limp mode. I called out Porsche Assist and an AA guy turned up who ran 2 system checks on the vehicle whereby no faults showed up.

As the car was ok the next day, I drove it to my nearest Porsche dealership in Tewkesbury. When they ran their system checks, no faults were found and they did a system update.

In November of 2024, the exact same thing happened whilst on my driveway. Upon starting the vehicle up, once again several warning lights appeared on the dash and the vehicle went into limp mode. Once again, the Porsche dealership, having ran their system checks, found no faults with the vehicle. At my insistence they kept the vehicle for a couple of weeks and consulted with Porsche Germany.

The technicians suggested that the vehicle may have detected dirty fuel or was extremely low on fuel. These were ruled out by myself.

This time, they ran 2 system upgrades and said the vehicle was good to go. I did not believe this to be the case and had them note that I did not believe they had identified the problem with the vehicle or rectified it.

On 19th February 2025, whilst driving the vehicle on a 50 mile per hour road, it went into limp mode and came to a grinding halt. I limped into a lay-by and drove the short distance home on electric. On this occasion the only difference was that there were no warning lights displayed on the dash.

The vehicle is now back at the Porsche dealership.

The vehicle is under full Porsche warranty.

My main concern is that to date Porsche have been unable to identify the fault with my vehicle and that it is clearly a danger to drive. Not only to myself but to other road users.

I really hope between us all, we could perhaps come up with a solution to my problem.

Many thanks for your time Randall, I look forward to hearing from you and other club members regarding this matter.

Best Regards

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Any comments / experience appreciated,

Randall

 

[Motorhead]

Hi Randall,

Indeed that is a very troubling - and extremely dangerous! - situation for the lady in question to encounter, and she is quite right to insist that the problem is solved completely before she takes-back the vehicle from the dealer.

Modern cars with complex CAN bus-based electrical systems with multiple sensors and electronic modules can only be interrogated with appropriate diagnostic analysers when problems arise and clearly both the AA and the dealer found no system errors … but presumably the problem wasn’t present at the time?

There are numerous reasons - electrical and mechanical - why a vehicle will go into limp mode, and I would have thought that an intermittent component, sensor or module fault would have been flagged-up by the diagnostics. Hopefully the Porsche technician will be able to have the PIWIS diagnostics connected when the problem presents itself to track the problem “live”.

The car is in such a dangerous condition that if the dealer is unable to rectify the problem completely - and to the lady’s satisfaction - I don’t think that they will have any option but to buy-back the car and/or offer her a replacement.

If she does get it back I think that I would make sure that the hybrid battery is kept charged fully at all times!

Jeff