Intermittent all wheel drive fault warning

[RandallF]

A member has enquired if anyone has any thoughts or has any experience of an intermittent all wheel drive fault warning as described below:

"I’m after some knowledge/advice please in regards to my Panamera GTS AWD. The vehicle was registered in October 2012 and has done 54,000 miles.

I have an infrequent fault that started a couple of months back and has just occurred for a fourth time. I think it’s a software issue but I would appreciate some guidance. Whilst driving a fault icon comes up on one of the digital screens outlining the all wheel drive system and declares failure. This is quickly followed by the skidding car icon declaring PSM disengaged. The car reduces speed then to around 35/40 mph. Pulling the car over as soon as I can, I’ve found that turning the car off, pulling the key out (as though I’m about to get out and lock it) waiting several seconds and then starting the car again it clears and the car is fine and drives as it should.

I don’t think I have a mechanical issue but given it can be anytime anywhere I do need to get a resolution and fix. Your thoughts or ideas on this would be very much appreciated and thank you for taking the time with this request."

Thank you

Randall

 

[lowndes]

Apologies for the delay in replying, I am not often in these parts, but in any event am only able to make some tangential observations based on my experience of a slightly similar condition. Interestingly the solution also turned out to be the automotive equivalent of CTRL/ALT/DEL.

I have a 74 plate G3 turbo hybrid, I picked the car up in early December on its winter tyres and headed for Switzerland via the Tunnel. I overnighted south of Epernay, then cross county via the Cote D’Or, Jura and Jaun Pass to the Berner Oberland. The car was faultless.

After a few days in Switzerland, I headed for home. It’s a total journey of a tad under 700 miles. I generally leave around 8.00am local, 9 hours to the tunnel, then depending on the state of the M20/M25 another 2/3 hours from the UK side of the tunnel to home. All was going fine until I started up to drive off the Shuttle at Folkestone when I got PSM failure, All wheel Drive failure, Diff lock failure plus host of other warning lights. It was cold, dark wet and the idea of calling Porsche Assist did not appeal. Save for a dashboard like a Christmas Tree all seemed to be working normally so I pressed on home arriving about 8.00pm. I took a few photos of the dash for discussion with OPC. I have pdf copy of the report I made so if you are interested pm me and I’ll send it

Next morning the car was normal, all faults clearly of the self-resolving type. As it happens, I had done the trip on a borrowed set of w/w as the ones I had ordered had been delayed. So when I went to OPC to exchange for my set there was the opportunity to check the fault codes. Over 70 faults had been recorded in the car’s memory.

In early January 2025 I did a repeat trip. This time all the same faults occurred on the outbound leg leaving the Shuttle at Calais. However, I was now wise to its little ways and stopped at the first Aire, switched off, locked the car and left it for 5 minutes. On return all was well and I continued on my way. On the homeward trip there was no problem exiting the Shuttle at Folkestone.

OPC have been very good about it and taken matters up with Germany. The short version seems to be that the loss of SatNav signal in the Tunnel confuses the car’s control systems which need a reboot in order to reset. Ironically the only system not confused by loss of SatNav signal is SatNav itself which continued to work at all times.

The issue seems to be that these cars are so complicated with so many interdependent systems that a failure in one area has a cascade effect and brings the whole lot down like a pack of dominos. That said, no one seems to be able to say whether important systems like PSM, all wheel drive etc are actually working even though they say they aren’t.

OPC are still on the case and if I hear anything further, I’ll report back.



PS

Anyone thinking of getting one, don’t be put off, it a nice car.

 

[RandallF]

Our 2017 Panamera GTS owner wishes me to pass on his thanks to the contributor above for taking the time to respond to his post. Echo that. He responds:

An update and a further question for understanding from any fellow members.

The diagnostic investigation registered an issue headlined Level Control (PASM). The explanation was then in German!! This read SPANNUNG FAHRBATTERIE TOO LOW KEIN AUSREGELN IM NACHLAUF MGLICH.

Believe that is something along the lines of “A problem with the voltage to the drive battery’. Would appreciate a more accurate translation if this is wrong. Equally I don’t believe it suggests too high or too low or indeed the source of the voltage issue, If anyone has had a similar experience of this error message (regardless of model) would be interested and presently I have held off any physical action or replacing something eg alternator etc as still not sure what the source is which would definitely recover things back to normal.

The software was rebooted and as previously has the car has run extremely well for last two weeks and then this morning has given me the icons and light show!! Very frustrating.

Anyway would again appreciate any feedback.

 

[RandallF]

The saga continues. Our GTS owner has provided a fresh update:

"Thank you for your note and background information. Also could you please thank the member for taking the time to respond on our Club Forum.

On Thursday 27th Williams Porsche Specialists in Cardiff replaced the battery and coded the necessary to the management system with assistance for the code from Porsche Newport. The battery I had was three years old in October and showed a below voltage of 11.6. So together with that, the information from yourself and the knowledge that other tablet software checks had not identified anything else apart from the Christmas Tree light show failures, it seemed to only leave the battery. The tablet was used afterwards and showed all well and no logged failures.

Beyond frustration, Saturday afternoon the light show returned!!! We were going shopping at the time and so arrived and parked up. Came back all well and car was fine. Bonkers. This afternoon I’m going back to Williams for software checks again but to be honest we don’t know what we’re looking for but Nick the owner said he was going to contact other independents for any ideas.

Thank you again Randall and I’ll keep you updated. Equally should anyone else have any ideas I’m unfortunately still in need of them."

 

[ZacJames]

Hi All,

had similar multi-fault xmas tree lights coming up on dash ( 5 year old cayenne turbo ) with no detrimental effect.
All the faults reset each time, after engine switch-off, but recurred often, usually a couple of days between. ( no faults stored in messages though, - weird )
Went on for a month or so, and I put it down to some transient software glitch.
Then, one day, same faults showed again, but, this time, car went into some sort of partial shutdown mode, and would not change out of 1st gear.

Eventually, vehicle trucked to Porsche Reading, and fault found to be one of the four wheel speed sensors had corroded, with age, and was not sending signal to ABS.
This caused ABS, and just about every other fault detection system to ’light up’
( chassis-steering-heated wheel-transmission etc )
1 replaced speed sensor later = All systems GO!
Just saying! Even if this isn’t the cause of your problems, this info might be of help to other models owners.