====== Head unit versions ======

Which software your head unit runs is shown under ''Settings › About'': tap the version entry about **5 times**, then three numbers appear. Only all three together tell you what fits your car.

^ shown as ^ what it is ^
| **AP version** | the head unit's apps — this is your app build (e.g. _060). |
| **System version** | the operating system: _060 means firmware 0051, _052 means firmware 0046. |
| **MCU version** | the head unit's microcontroller. It talks to the rest of the car (CAN bus). Our sticks never change it. |

===== Why the MCU version matters =====

Apps and MCU must speak the same "language". In app builds 030, 052 and 060 it is the same; with 102, 104 and 108 the manufacturer changed it (checked in the apps' code). If 102, 104 or 108 runs on an MCU of the older language, our analysis says vehicle data such as doors, gear or range would no longer arrive, and some commands would be misunderstood. We have not observed this in a car. So: **never install an AP version that speaks a different language than your MCU** — i.e. no 102, 104 or 108 on an MCU version _030, _052 or _060.

===== What left the factory together =====

From the manufacturer's factory records (version combinations only, no vehicle data). They show the factory state — later dealer updates are not included. Look up your **MCU version** in the first column.

^ MCU version ends in ^ AP version from the factory ^ System version ^ Firmware ^ newest AP version speaking the same language ¹ ^
| _010 | 010 | _010 | ? | ? |
| _012 | 015 | _012 | ? | ? |
| _014 | 017 | _014 | ? | ? |
| _020 | 020 | _020 | 0016 | ? |
| _030 | 001, 030, 048 | _030 | 0024 | 060 |
| _052 | 052 | _052 | 0046 | 060 |
| _060 | 060 | _060 | 0051 | 060 |
| _070 | 076 | _060 | 0051 | probably 104 ² |
| _073 | 086 (rarely 076) | _060 | 0051 | probably 104 ² |

¹ Derived from the apps' code, **not tested in any car**.
² 104 did not leave the factory; it came later with a manufacturer update (vehicle version 1.9.2). Which MCU version those cars have, we are checking right now.

===== What you can do with it =====

  * **Stock firmware sticks** exist for AP versions 052, 060, 102, 104 and 108: [[:software:stock_firmware|Stock Firmware]]. Take the stick of your **current** AP version. Switching to another AP version of the same language (e.g. from 052 to 060) works with the stick of the new version, deletes all data and leaves the MCU as it is — nobody has tried that in a car yet.
  * **ADC** runs on AP versions 052, 060, 102, 104 and 108 with firmware 0051: [[:software:adc|ADC]].
  * If your combination is missing or you have 102, 104 or 108: send us your report with the [[:software:backup_stick|backup stick]] — or write us your three numbers.