# Modules

Now that we've covered the history, the only modules we can use are the Electro Mechanical modules. We currently know of a few modules which are being used.

The most relevant part of the part number is the first three characters. The first two characters indicate the revision of the EPS, the last letter indicates which side it's for, 1 will indicate RHD, 2 indicates LHD. This page will substitute the 3rd character with X.

<table><thead><tr><th width="164.55783685685248">Part Number</th><th width="182">Accepts HCA</th><th width="200.44884148051642">Used In</th><th>First Seen</th></tr></thead><tbody><tr><td>1SX 909 144</td><td>No</td><td>UP, Citigo, Mii</td><td>?</td></tr><tr><td>6RX 909 144</td><td>No - Unsupported State</td><td>Polo 6R, Skoda Rapid</td><td>?</td></tr><tr><td>6CX 909 144</td><td>Yes - Doesn't steer</td><td>Polo 6C, Skoda Fabia, Skoda Rapid</td><td>2016</td></tr><tr><td>2QX 909 144</td><td>Yes</td><td>Polo AW, T-Cross, E-UP (2019+)</td><td>2019</td></tr></tbody></table>

Curiously, the 6CX 909 144 EPS responds to HCA commands and puts itself into a state to reflect this, for some reason the EPS never actually steers. The cause for this is unknown, the 6RX 909 144 EPS instead returns a non supported state instead. There has not been much research on this phenomenon however, [Willem Melching did some research on another Volkswagen Group power steering rack which revealed some interesting calibration zones.](https://blog.willemmelching.nl/carhacking/2022/01/02/vw-part1/)

Unfortunately, only one EPS actually works, the 2QX 909 144. This column is fitted to both PQ and MQB cars allowing it to be used in all Polo-esque cars. This is achieved by using one of two different versions of firmware, one communicates using PQ messaging and the other one using MQB. The firmware for this is available, however you will need to purchase a tool capable of flashing firmware. *(link to next section about flashing fw)*


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