Piwi diagnostic program for Porche Taykan

[whitex]

One thing that has not been discussed is that you need a 100amp 12v battery charger to be connected while you are using PIWIS

This is not needed when diagnosing a Taycan, as long as the HV battery has charge and is not disconnected via the safety disconnect. The very first thing PIWIS will do upon connection to the car is show a warning displayed in the instrument cluster that HV battery is active. The DC-DC converter will keep the car powered for a long time no problem, as long as the car is ON (which is required for the PIWIS tool to operate).

Now, if you're working on a 911 or other Porsche ICE cars, then yes, you need an external 12V supply.

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[Shug]

Hate to disagree with you whitex, I have experience in this with Taycan and can confirm that it was a problem for me.

 

[whitex]

Hate to disagree with you whitex, I have experience in this with Taycan and can confirm that it was a problem for me.

Hmm... have you ever run your 12V down while the car is ON and PIWIS connected?

 

[Shug]

https://static.nhtsa.gov/odi/tsbs/2020/MC-10172088-0001.pdf

Might give you an idea of how to operate some of the menus in PIWIS, it also mentions the use of the battery charger.

Whilst you could give it a go without a battery charger, I did not know it was even a thing till I ran into problems.

What I can say for sure is that I would always connect the 100amp charger when working with PIWIS.

 

[Shug]

Hmm... have you ever run your 12V down while the car is ON and PIWIS connected?

Yes

 

[whitex]

Yes

If this happens to your car, you'd also run down your 12V battery while driving. What test were you running via PIWIS and for how long to run the 12V battery down?

 

[Shug]

The test I was generally running was F7 to clear all faults prior to working on individual items of interest.

As the voltage crept down, the test went slower and slower, but did not take long to get to just above 13 volts.

When it got to 12 volts, I was concerned and shut the session down.

Somewhere it advises you that if you let the voltage drop, it may damage some of the units.

 

[carlos vilarinho]

Last piece of advice, stay away from bright orange wires, they are always high voltage (you can see some of them on the picture with the safety interlock, connected to the heater and the onboard charger).

I really have no intention of touching the outside of the car, quite honestly, and I don't think there are any high-voltage orange cables inside the car. I only asked for information about disconnecting the 800V battery just to feel more protected, nothing more. If the car needs to have its CC/CC changed, I won't even touch it. I'll find someone to do the job for me. Those orange cables are dangerous. I don't even think about touching anything on the outside or inside of the hood. The only thing I disconnected and connected in that area was the 12V battery, the negative cable of which I removed when I disassembled the back door and reassembled it, along with the broken glass!

 

[Shug]

There are no 800V cables inside the passenger compartment.

This switch in the centre rear of the Frunk disables the 800V system and makes it safe to work on.

The tab at the top of the switch pulls up pretty easily, but requires a small screwdriver inserted on the front to get a tab out of the way to close it.

 

[carlos vilarinho]

I really have no intention of touching the outside of the car, quite honestly, and I don't think there are any high-voltage orange cables inside the car. I only asked for information about disconnecting the 800V battery just to feel more protected, nothing more. If the car needs to have its CC/CC changed, I won't even touch it. I'll find someone to do the job for me. Those orange cables are dangerous. I don't even think about touching anything on the outside or inside of the hood. The only thing I disconnected and connected in that area was the 12V battery, the negative cable of which I removed when I disassembled the back door and reassembled it, along with the broken glass!

 

[carlos vilarinho]

There are no 800V cables inside the passenger compartment.

This switch in the centre rear of the Frunk disables the 800V system and makes it safe to work on.

The tab at the top of the switch pulls up pretty easily, but requires a small screwdriver inserted on the front to get a tab out of the way to close it.

There was a question here that you didn't answer for me: can I disassemble the side plastics, the plastics of the belts, the top lining... check the car's electrical wiring without taking any risks... as long as I disconnect the positive pole of the 12 V battery... this is inside the car...???? I previously checked all the fuses in the car and I don't have a single blown fuse... Obviously, if you also turn off this switch to turn off the 800 V, I think it's even safer!!!!! Is there only one switch on the front or is there also one on the back that also needs to be turned off????

 

[Shug]

PIWIS does all the heavy lifting for you in terms of where the issues are and it also allows you to reset the electronics so that where something has been corrupted, it can be reset using the PIWIS menu system.

The 12V battery can be easily disconnected (remove the earth strap) should you need to work on something.

There are several fuesboxes around the car, the hardest one to get to on a RHD car is inside the right hand side of the boot / trunk where you have to dismantle all the internal panels to expose the fuses, there are fuse panels, left and right at your feet, on the outer edges of the dashboard and one in the frunk, it's a black oblong box and finally there are layers of wires with big fuses on the top of the 12V battery.

Important point with electronics, you must pull the earth strap, not the +. If you pull the + you may get a big spark that will corrupt the electronics.

 

[Shug]

As far as dismantling the internal panels, you do not need to disconnect the 12V battery to do this, there is nothing behind the side panels other than the airbag wiring.

If you are looking inside the doors, be aware there is a calibration routine that is required for the windows, I would keep the 12V battery connected while I pulled the panels off.

Clearly if parts need switching out, you can take a view, but with the ignition off there will not be power to many parts around the doors.

 

[carlos vilarinho]

As far as dismantling the internal panels, you do not need to disconnect the 12V battery to do this, there is nothing behind the side panels other than the airbag wiring.

If you are looking inside the doors, be aware there is a calibration routine that is required for the windows, I would keep the 12V battery connected while I pulled the panels off.

Clearly if parts need switching out, you can take a view, but with the ignition off there will not be power to many parts around the doors.

What I need to research are the wire harnesses in the part that passes under the plastic of the doors that give power to the front and rear safety lights... and the wire harnesses that pass above the parcel shelf that pass through the airbag curtains and give power to the rain sensor etc... the Porsche guys were saying that there can always be high voltage inside the car (I found the comment a bit strange, I think it was more so that I wouldn't have to dismantle anything inside again)

 

[carlos vilarinho]

Just to give you an idea, this was the state of the back door lining that was vandalized and the glass was broken. The lining was replaced and inside there was absolutely nothing burned or damaged, the glass was in perfect condition and so was the door! in other words, a before and an after…

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