Tesla Model 3 Charger/DCDC ("PCS")

Overview

The Tesla Model 3 has a "Power Conversion System" (also known as the "PCS") which contains both a 10kW AC charger and a ??W DCDC converter. The PCS is located inside the "Penthouse" part of the main traction battery system.

Learning/Resources

Video - The Tesla Project : Model 3 PCS First Look - https://youtu.be/_TYvSmDJSPQ

Video - Tesla Model 3 Power Conversion System - https://youtu.be/3ARHdRwfxjY

OpenInverter PCS overview/tech thread: https://openinverter.org/forum/viewtopic.php?f=10&t=171

OpenInverter PCS controller support thread: https://openinverter.org/forum/viewtopic.php?p=27744#p27744

Damien's GitHib: https://github.com/damienmaguire/Tesla-Model-3-Charger

Hardware

Controller

Damien from EVBMW has designed a control solution which is open source hardware and software. Design files for the controller hardware and software sources are available on Damien's GitHub here. Controllers are also available as a fully-built kit (with pre-loaded software) on the EVBWM webstore.

Data Connector on PCS (12-way)

EDITOR'S NOTE: my research shows some conflicting/different part numbers mentioned - would appreciate some clarification here once validated

As per: https://openinverter.org/forum/viewtopic.php?p=26614#p26614

The connector used for communications with the PCS:

Pins:

In true Muskian fashion it seems they use the 1379662-5 natural color variant of the plug which has no coding tabs. It is of course unavailable from mouser. The black and green variants are functionally identical and should work with coding tabs removed.

annotated view of PCS data connector viewed from the front

However, as per: https://github.com/muehlpower/EV-FFB, there is also mention of 1318774-1 (white) or 1318774-2 (black) for the comms/data connector.

Power Connectors

The power-side connector assemblies are not widely available. The housings are a Tesla internal part (photos/part numbers here), however, 3D printable housings have been made available here. The terminals also aren't widely available, but are known. As per https://github.com/muehlpower/EV-FFB:

Note: the US variant of the charger (1-phase) has a different AC pin layout; see photo for reference.

The contacts for 400V are Uni F630 from MTA, part number 1107940. For 12V Kostal PLK 14.5, part number 23124734300. The connector for the data is from TE connectivity, part number 1318774-1 for white or 1318774-2 for black.

AC connector pinout for US Model 3 PCS (1-phase)

Connections

The minimum wiring needed to wake the PCS:

1. PCS controller connected to PCS via 12-way X420
2. PCS controller is powered via 20-way +12V input pin and grounded to chassis via 20-way ground pin
3. +12v and Chassis ground applied to PCS 12v Connector input terminal
4. Chassis ground on the PCS case

Firmware

Current Version

The current version of the PCS firmware can be found here: https://github.com/damienmaguire/Tesla-Model-3-Charger/releases

The current firmware will auto detect what Tesla firmware is installed on the PCS and adjusts the CAN messages accordingly (different versions of the PCS firmware from Tesla have different CAN requirements). It will also auto detect if the PCS is EU or US spec and whether single or three phase AC is connected. It also includes an integrated alert logging function to help diagnose any issues the PCS sees.

Alerts Logging

The PCS has an array of potential alerts to help diagnose issues. The images below show a matrix of potential alerts

Initially alerts had to be identified through CAN logs (PCS IPC CAN). In later firmware releases, the PCS web interface incorporated a decoder to help identify alerts (decimal number identifier relating to the alert tables shown here). In the current version of firmware, the alerts are now displayed in word format to make it easier and quicker to troubleshoot.

Testing

First Power Up

Set up to initially test connections between a PCS and the PCS controller are straightforward. This can be done without any HV DC battery or charging connected to the PCS. Once the PCS controller is connected to the PCS (follow the relevant V2 or V3 pin-outs) the basic steps are:

1. Connect the PCS aluminium case to LV ground
2. Connect PCS controller ground wire to 12V ground
3. Connect PCS 12V power wire via a 5A fuse to +12V
4. Observe the PCS controller continuous 3.3V indicator red LED and the flashing activity red LED
5. Connect to the PCS controller wifi to view the web interface. The interface will indicate that the PCS 'opmode' is 'Off' at this time
6. On the web interface, change 'inputype' to 'Manual' in the drop down menu and select refresh at the top of the screen
7. On the web interface, change 'activate' to 'Both'. This will tell the PCS to try start DC-DC and Charging if enabled (as above, these are not connected at this time so will generate alerts that will be mentioned further below)
8. On the web interface, change 'AlertLog' to 'On'. This will tell the PCS to show any alerts
9. To enable the PCS connect the PCS controller 'Input 1 (enable)' wire to +12V and select refresh at the top of the screen. 'Opmode' should now change to 'Run' on the web interface to show the PCS is now operational
10. At this point, 'PCSAlertCnt' will likely show a number indicating the number of alerts the PCS has flagged and 'PCSAlerts' will show the first alert
11. To see each alert separately, under General, change the number in the 'Alert' option (0 indicates first alert and should be default) to the next sequential number and select refresh at the top of the screen. 'PCSAlerts' will now show a description of the selected alert. Do this to step through each alert (total number indicated by 'PCSAlertCnt')
12. Typical alerts with this configuration (no HV DC battery or charger interface connected) will be: 63chgVOutRationality, 66dcdcHVRationality
13. Now the connections and communication with the PCS and controller are established, further testing can be carried out to check DC-DC and charging functionality. See below
    

DC-DC First Test

TBC

AC Charging Test

TBC

Confirmed Working Models

to date a number of PCS units have been tested and confirmed to work with the current firmware: 1x 3p EU PCS from circa 2020 model year car 1x 1p US PCS from circa 2018 model year car. Running in BMW E46 touring conversion 1x 1p US PCS from circa 2020 model year car

The minimum recommended HV DC battery voltage for testing is 250V (This needs to be confirmed)