Retrofitting PCM4 in a 991.1
#1
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Retrofitting PCM4 in a 991.1
I'm about to attempt a PCM4 retrofit on my 991.1 GT3 and would like to document the process so others can see what's involved. Note this isn't a how to, this post serves as a journal of my progress. I've done this before in my Audi, and the PCM4 is Audi's MIB2 hardware running Porsche software, so I have high hopes that this is possible.
To start off, here's the parts I ordered and cost.
PCM4 Central Computer + Display w/ GSM, NAV, SXM, AM/FM, CarPlay, $700
Quadlock Female to Male Extension Cable (to rewire into PCM3.1 to PCM4 adapter harness) - $15
6-Pin TE MultiLock Connector (for wiring Quadlock grey block to display panel) 174044-2 $4
Fakra HSD Female to Female Cable (for LVDS to display panel) $19
Cellular antenna, Fakra A connector $5
Sirius XM antenna, Fakra A connector $11
Fakra B (dual) to Fakra A (single) adapter cable (to adapt AM/FM and Cellular to existing antennae) 2 @ $8ea
MOST Fiber Optic Y Splitter Cable $8
MOST Fiber Optic Extension Cable $8
--------
Total BOM $786.
PCM4 is vastly different from PCM3.1 so this is not a drop-in replacement. I will be re-wiring essentially the entire connector block, and anybody that chooses to do this retrofit, please ensure that you're comfortable with electrical work. Once the unit is wired, it must be coded to the car so it's properly configured for any installed equipment, displays the correct model on boot-up, etc. Wiring and coding information will follow in a future post once I receive and re-wire the adapter harness to install this head unit in my car. Wiring diagrams are available via PIWIS TSI.
In my previous retrofit attempts, I have had to bring the car into a willing dealership to have component protection deactivated, the cost is typically a few hours of labor, but I'd like to avoid the dealership altogether for this retrofit. So while I am awaiting the parts from China, I have the PCM4 system out on the bench and am in the process of pulling firmware from the NOR and eMMC for further examination.
For others who would like to examine the inner workings of PCM and contribute, I have attached some pictures of some pinouts that I've traced out for UART and the eMMC TPs. The system runs QNX, and the UART interface prompts for a login which I do not know the password for. I'll find the hash from the eMMC dump and post the password once it's found (the password does change with each release)
To start off, here's the parts I ordered and cost.
PCM4 Central Computer + Display w/ GSM, NAV, SXM, AM/FM, CarPlay, $700
Quadlock Female to Male Extension Cable (to rewire into PCM3.1 to PCM4 adapter harness) - $15
6-Pin TE MultiLock Connector (for wiring Quadlock grey block to display panel) 174044-2 $4
Fakra HSD Female to Female Cable (for LVDS to display panel) $19
Cellular antenna, Fakra A connector $5
Sirius XM antenna, Fakra A connector $11
Fakra B (dual) to Fakra A (single) adapter cable (to adapt AM/FM and Cellular to existing antennae) 2 @ $8ea
MOST Fiber Optic Y Splitter Cable $8
MOST Fiber Optic Extension Cable $8
--------
Total BOM $786.
PCM4 is vastly different from PCM3.1 so this is not a drop-in replacement. I will be re-wiring essentially the entire connector block, and anybody that chooses to do this retrofit, please ensure that you're comfortable with electrical work. Once the unit is wired, it must be coded to the car so it's properly configured for any installed equipment, displays the correct model on boot-up, etc. Wiring and coding information will follow in a future post once I receive and re-wire the adapter harness to install this head unit in my car. Wiring diagrams are available via PIWIS TSI.
In my previous retrofit attempts, I have had to bring the car into a willing dealership to have component protection deactivated, the cost is typically a few hours of labor, but I'd like to avoid the dealership altogether for this retrofit. So while I am awaiting the parts from China, I have the PCM4 system out on the bench and am in the process of pulling firmware from the NOR and eMMC for further examination.
For others who would like to examine the inner workings of PCM and contribute, I have attached some pictures of some pinouts that I've traced out for UART and the eMMC TPs. The system runs QNX, and the UART interface prompts for a login which I do not know the password for. I'll find the hash from the eMMC dump and post the password once it's found (the password does change with each release)
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#2
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But isn’t the communication protocol different on the 991.2? I thought that was the reason the .2 MF steering wheel cannot be retrofitted without an adapter translating the communication. That said, the new interior mirror can be retrofitted without issues. Maybe you can shed more light on this.
But isn’t the communication protocol different on the 991.2? I thought that was the reason the .2 MF steering wheel cannot be retrofitted without an adapter translating the communication. That said, the new interior mirror can be retrofitted without issues. Maybe you can shed more light on this.
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#10
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But isn’t the communication protocol different on the 991.2? I thought that was the reason the .2 MF steering wheel cannot be retrofitted without an adapter translating the communication. That said, the new interior mirror can be retrofitted without issues. Maybe you can shed more light on this.
But isn’t the communication protocol different on the 991.2? I thought that was the reason the .2 MF steering wheel cannot be retrofitted without an adapter translating the communication. That said, the new interior mirror can be retrofitted without issues. Maybe you can shed more light on this.
I left all of the parts at work so I'll have more updates this week, should have the firmware pulled tomorrow to take a look at how the system functions.
Last edited by chris2; 05-13-2019 at 12:04 AM.
#11
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#13
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Parts got delayed, the main wiring harness is stuck in customs still but the board that will allow me to dump the firmware from the PCM4 arrived today. I'll have to look at the firmware dump and find out how to bypass component protection and feature activation codes, but I won't be able to do much work on this until mid next week. More to follow soon