MCU2 Upgrade and AM/FM/XM Radio Issues

Tesla is now offering an upgrade from MCU1 to MCU2 for $2500 for cars with HW2.0 or HW2.5. The retrofit will not work in older cars, made before 1-Oct-2016, considered HW0 or HW1. More details are available on the Tesla Infotainment Upgrade page.

Additional improvements not mentioned, include an updated display with no yellow banding issues, flash memory that should last about 4 to 8 times longer than the memory used in MCU1, and the ability for future features that will not work in MCU1. For those replacing MCU1 out of warranty, switching to MCU2 makes a lot of sense.

While it offers a number of improvements, it will remove the AM/FM/XM radio functions. This is because the radio module, separate from the MCU, is analog in MCU1 and all digital in MCU2.  We’ll outline all the options available.  (Created Mar-2020)

Options Available
  • Don’t Upgrade – This, of course, keeps your existing radios
  • Upgrade to MCU2 – Radios are removed, but there are options:
    • Live without AM/FM/XM
    • Use streaming audio with TuneIn, which supports many AM and FM stations
    • Use your phone with Bluetooth to stream XM radio with the XM radio app
    • Buy an external XM radio (See our XM Radio article)
    • Buy an external MP3/FM player that supports Bluetooth 5.0 (untested, but may work – antenna may be tricky)
    • Replace the analog radio with the MCU2 compatible digital radio for FM/XM (in theory – see below)
  • Buy a new Car that has MCU2 and FM/XM radios

Tesla has completely discontinued AM radios in all cars for several years now, and any possible upgrade will not include AM as the digital modules do not include AM radio and it’s unlikely MCU2 has any software to support AM radio.

Upgrading the Analog Radio to Digital

As of this writing, we are unaware of anyone taking this path. According to service, it is not possible to make FM/XM work with the retrofit, but we are not convinced. While we’ve not tried it yet, we’ve outlined the primary steps that could make it work.

  • Purchase of the MCU2 compatible digital radio.  There are different radios as noted for the USA market. If your car does not have XM radio, you will likely need to buy the non-XM radio version although perhaps the FM/XM radio version would work.  See below for part numbers.
  • Hopefully, the existing antennas will work fine. It appears Tesla uses the same antenna connectors, but they are now in a different location and may require a short extension
  • Purchase the mating female connector for the analog radio’s harness, a PCB mount
  • Purchase the mating male connector for the digital radio
  • Create a new wiring harness to connect the power and data from the existing analog connector to the digital connector. I expect a small PCB will be needed due to the PCB mount connector. In addition, data wires will need to be run to the MCU2 connector.
  • To be determined, but the retrofit connector that connects to MCU2 may require modifying
  • Have Tesla service run the Vehicle Firmware Update procedure to enable the new radio. It is very possible Tesla service is not allowed to perform this last step, which is required!
Removing the Radio Module Summary

The radio is mounted to the left of the steering column behind the padded dash panel. #4 in the image below. There are two modules next to each other. The left module is the premium amplifier for cars with UHFS, and the right module is the radio tuner. It is not all that easy to access, but we’ve outlined the basic steps to get to it.

disassembly

Disassembly steps 1 through 7

  1. Position the driver’s seat as far back as possible for easier access
  2. Remove the dash driver’s side panel and disconnect the FOB antenna
  3. Remove the screw that holds the footwell cover to the under-dash and remove the cover
  4. Remove the driver’s side padded lower dash trim that is left of the steering wheel, held on by 9 strong snaps
  5. Remove the driver’s side trim of the center console, held on by 8 clips and an adhesive pad
  6. Remove the two screws that hold the under-dash closing trim and partly remove
  7. Disconnect the footwell lamp mounted to the under-dash closing trim and remove the trim
  8. Remove the 3 bolts holding the retaining bracket to the cross-car beam
  9. Lower the retaining bracket to provide easier access to the radio module
  10. Remove the connectors attached to the radio module
  11. Remove the 4 screws holding the radio module
  12. Remove the radio module.

It may be helpful to see a video on Removing MCU1.  It shows some of the steps we outline above as well.

Analog Radio Details
The analog radio has 3 or 4 connections depending on the radio installed. One 16-pin connector is for the power, control, and stereo line-level outputs. A dual antenna connector is for the two FM antennas, and one is shared for the AM antenna. For cars with XM radio, another connector is used for the XM antenna (not shown). The analog radio is made by Panasonic and manufactured in China.
analog radio

The rear of the analog FM only radio

Female Connector: Molex 34729-0160 used on the wiring harness – do not buy this version!  To connect to the existing wiring harness, you need male version Molex 34690-0160, The mating connector is only available as a PCB mount. One could also cut off the existing connector and wire it to a new connector that fits the digital radio. We hate making changes that can’t be undone, so I don’t recommend it. Your tolerance for modifications may be higher than mine!

Pin Abbreviation Description
1 KL15 12V via 10 amp fuse
2 no connection
3 no connection
4 no connection
5 Aux_SHLD Shield for Line out, Left
6 Aux L- Line out, left, differential, 10KΩ
7 Aux L+ Line out, left, differential, 10KΩ
8 KL31 Ground
9 no connection
10 CAN+ CAN 2 data bus, differential
11 CAN- CAN 2 data bus, differential
12 no connection
13 Aux_SHLD Shield for Line out, Right
14 Aux R- Line out, right, differential, 10KΩ
15 Aux R+ Line out, right, differential, 10KΩ
16 KL31 Ground

 

Digital Radio Details

The digital radio is much smaller and is mounted on a bracket that fits into the same spot where the analog radio resided on older cars.  It has the same style antenna connections (shown on the right) but a different data connector on the left. There are no AM radio electronics in this module, so there is zero hope for those that want AM radio. The digital radio is made by Harman (now a Samsung company) and manufactured in Mexico. The radio module, not including the bracket, looks very similar to the Model 3 FM radio, which has a third connector to power the antenna amplifier. I suspect a model 3 radio could be used if you don’t need XM since the connectors appear the same. You would have to fabricate a new bracket. I only mention this, as eBay has a number of used Model 3 FM radios, but I’ve not seen any Model S/X radios for sale. The reported cost for a new Model S/X radio is $280.

digital radio

Top view of FM only digital radio

Side with the 10-pin connector for power and data

We are still investigating the wiring and how it may be connected to the MCU2.

Tesla Parts

Here are the latest Tesla part numbers for various items:

Description Part Number Notes
MCU2 Upgrade (includes labor & MCU2) 1582613-00-A Tesla service only
Radio, FM/HD, Model S 1143703-00-C No sale restrictions
Radio, FM/HD/XM, Model S 1143711-00-C No sale restrictions
Radio, FM/HD, Model X 1143705-00-B No sale restrictions
Radio, FM/HD/XM, Model X 1143716-00-C No sale restrictions