Hi all, Ive got a Panamera Diesel and had a intermittent issue with the PSM Failure.

Whilst driving he PSM suddenly fails and send the car into shut down mode. This has happened when I've been doing 70mph so its quite scary as you loose power and it rattles off a load of stuff on the screen like PSM FAILURE, AIR SUSPENSION ERROR, TRANSMISSION FAULT, COOLANT ETC ETC

Whats stance is that I restart the car in the morning and all the lights etc are clear and it acts normal, drives no issues etc. I've had a diagnostics done and the reads are attached, surly its not all the things listed.

Wondered if anyones had this issue or know of the issues and how to resolve it???

Also my alarm keeps going off without anyone seeing anywhere near the car..?

Thanks in advance

 

I don't have a list of code breakdowns, and I'm unsure about the diesels, however the last time I got similar faults at speeds like that, it was because of 2 coil packs. The minute I changed them out and reset the faults, it was good to go.

Hopefully someone else can chime in with actual diesel experience.

 

Check battery condition. If over four years old, replace it now.
If battery is in good contition, including age, try the old technique of "rebooting". It is EZ/PZ to do. Just disconnect both battery leads from the battery. Then connect the leads together for at least ten minutes. This will discharge without harm several memory capacitors. When you reconnect the car will "relearn" acting like it first did when initially started at Porsche Assembly.

 

Same issue resolved by replacing one bad coilpack

 

Just out of interest how did you know which coil pack was bad and also how much was it to sort? Did you take it to Porsche or a Specialist? Thanks

I had a similar issue with Coil Packs on my Audi but Audi replaced them FoC under a warranty or recall... I was Confused but very happy!

 

Diesels don't use spark plugs, they use glow plugs. I do not believe they have the same coil packs.

Alternator is a concern to me.

 

Are you suggesting an issue with the Alternator based on the readings in my images or based on another reason/past experience?

 

My clue was the unusual failures at speed, 70 MPH is quite fast. A healthy alternator should be able to overcome and mask a weak/bad battery when it is running at speed. I would shift my suspect to bad battery if the failures happen in stop and go traffic/around town.

Also I was concerned with the description given for code C11000, the supply voltage low message.

 

They happen at all times really not at a set speed.

Had the battery tested yesterday and (in the words of the mechanic) "its purrrfect"... I hate how much electrical crap are in cars (set to only get worse), makes issues so much harder to resolve!

Im once again stumped to why this is happening. All the reads seem to point to a gateway module so maybe thats at fault..? 🤷‍♂️

 

What does your voltage say on the dash when it happens?