McIntosh PF-2824I and PF-4113I first glance

2015-03-27I now have on hand a Clarion/McIntosh PF-2824I and PF-4113I head units. These are fitted to higher end Subaru Legacy vehicles produced between 2005-2008. It includes MP3 and WMA support (why they didn’t support AAC instead of WMA beats me), a dual row VFD display and a more integrated look than the previous version (PF-2551I).

The PF-4113I is the Japanese version of the PF-2824I with a different tuner and a MiniDisc player. They are built around the same hardware platform (most components are the same including the PCB), however unfortunately run slightly different firmware. Unlike the previous model of McIntosh head unit in 2003-2005 Legacys, there is no easy way to convert the PF-4113I to European or American FM bands without hacking or replacing the firmware. There does appear to be a Micom firmware upgrade port on the side of the main board in the unit, however it appears that the microprocessor is of a mask ROM type and therefore cannot be flashed with new firmware.

It does use the same FM tuner module as many older McIntosh units, so if the firmware were to be sorted the necessary tuner mods are very simple.

Under the left hand seat is the EF-1259I amplifier. Unlike the old EF-1080I, this amplifier does not contain any EQ or crossover components as all this is now done in the head unit.

McIntosh Secret Key Combinations

After a bit of reading I’ve found that many Subaru head units have hidden options for changing settings. I couldn’t find much information on this unit so I spent a few moments trying various combinations to see what happens. Here’s the list I’ve discovered so far. If you discover any more please let everybody know by posting it in the comments!

To use these key combinations, switch the ignition to ACC and make sure the head unit is powered off.

Radio Location

Press the following to change the radio tuner region.

2 + AM is EXPORT (North America)
5 + AM is AUS & EXP

Here are the differences between these modes:

Location AM Range AM Step FM Range FM Step
Australia 531–1620 kHz 9 kHz 87.5 – 108 MHz 100 kHz
Export 540–1610 kHz 5 kHz 87.5 – 107.9 MHz 100 kHz
Aus & Exp Same as Australia

Note that switching locations will erase the radio presets.

5 + AM is JAPAN

Display firmware version

Press 5 + 6 + FM


PF-2824I (Japanese manufactured):
M 4.20

M 5.60
G37.00 0.37

Disc 1 on the display lights in both cases too. If anyone has details for Chinese-manufactured versions of the radios please let me know.

Button and Display Test

5 + 6 + press RPT twice

Button test that displays the name of any button you push as well as the tuning up/ down.
Use the volume knob to toggle the display test feature which illuminates every display element and LED. When in display test you can use the tune knob to toggle a checker board pattern to more easily view display state. This will make any phosphor burn very obvious!

To exit this mode switch the ignition off.


In previous McIntosh models this was an analogue circuit built into the amp or head unit. It’s now all software controlled so can be changed between a number of presets or bypassed completely. This is very useful if you buy a replacement unit, so you can have it sound like the original if it needs to be replaced.

Press the following buttons and T/B:
2 + 5 + T/B THROUGH MODE (bypass)

I haven’t investigated the frequency response of each setting, however after a very quick listen the sedan options appear to have more bass than the wagon (quick bass boost option if you have a wagon!) and the cloth seat options appear to have a little treble boost. While it’s intended to compensate for the acoustics of the vehicle interior, purists might prefer to bypass the EQ altogether.

Loudness Control

Unlike the other settings, this must changed while the unit is powered on.

To toggle loudness, press 5 + 6 + T/B.

The default setting is on.


Press 1 + 4 + CD to enter some sort of diagnostics mode. This displays the following:

H01 A1 256

Use tune to scroll through various options. As far as I can it seems to be read only. It also plays the current CD and the volume control works normally while in this mode.

Clarion and McIntosh parts

I recently had somebody refer me to PacParts who turn out to be an excellent source of spares for Clarion and McIntosh car audio. Parts include laser pickups, spindle motors, tuner modules, LCD/VFD displays, knobs and more.

Unfortunately they only ship to the US, however there are many companies around who offer international parcel forwarding such as Shipito.

Clarion CeNET – a first glance

I’m keen on reverse engineering at least some aspects of the Clarion CeNET bus in order to hook other gadgets to my car stereo. CeNET is a proprietary interconnect used by Clarion on many of their car audio products over the last ten years.

It uses a proprietary 13-pin square DIN style connector that is not available off the shelf. The pinout is shown below (this was taken from a Clarion service manual).

Electrically, CeNET appears to be a form of asymmetric serial bus. There is some discussion online that suggests a 38400 baud rate. The same person also says that it appears to use some form of encryption which may make it difficult to hack.

My experience with CeNET stereos is that the display will flash SYS or SYSTEM if the battery is disconnected or a CeNET device is inserted or removed. They do this until the stereo is powered on. Perhaps an encryption key is negotiated during that period?

On the hardware side, closer inspection reveals the bus consists of a transceiver IC (CA0008AM) connected to one of UARTs in the host devices microprocessor as shown in the simplified diagram below. Note that there are also some pull-down resistors on the Tx and Rx pins, as well as a 68 Ohm termination resistor across the Bus+ and Bus- pins. I’m unable to find data on the bus transceiver but I guess it’s possible that other generic ICs could be used here. The bus itself floats at 2.5v and swings +/- 200mV during signalling.

I have capture some data samples from a stereo connected to a EA-1251B iPod adapter that emulates a 6 disc changer. I haven’t yet studied them in detail but you can download the capture files below.

You will need to download Saleae Logic to view the capture files (it’s free). The cables were connected according to the colours in the diagram below:

In all captures I powered on the stereo from cold (no battery) immediately, then switched the unit on after about 3 flashes on the display (4-5 seconds). With the EA-1251 samples I switched from radio to the CD changer at about 7-9 seconds. From here the stereo waits for the iPod to wake up (it thinks the CD changer is loading) before it starts playing the first track of the first ‘disc’ (playlist) at about 14-15 seconds. The song then continues to play until the end of the capture.

Update: I’ve also grabbed a couple of samples of a TV tuner and display.

When the TV tuner is selected via the TV display it places the head unit into aux mode (it displays Aux on the screen). This could be a very useful hack; to make a ‘proper’ CeNet aux input. In the samples above, all units were powered up from cold (no battery) immediately after beginning the capture. The head unit is switched on at about 4 seconds, then there is a bit of wait for the display unit to boot up. Once this is done I’ve switched to the TV tuner at about 27 seconds. Shortly after (about 35 seconds) I switch back to the head unit’s internal FM radio.

It turns out trying to capture the bus pins was a waste of time as they normally float at 2.5V. I haven’t been able to look into that side of things any further as my only oscilliscope died before I could check it.

Hopefully somebody else finds this useful. I’ll keep working on it as I get time, and post any updates to the site if i come up with anything.

Japanese import FM tuner conversion

This post describes how to modify a McIntosh PF-2142I (often but incorrectly referred to as PF-21421) JDM car radio to natively tune from 87.5-108MHz as used in most countries around the world. This model of radio is fitted as standard equipment in many JDM Subaru Legacy and Outback cars manufactured between 1998 and 2003. Read more of this post

Clarion aux input

Here’s a quick and simple project to get a proper auxillary input for your iPod, etc on some models of Clarion OEM stereo.

I’ve posted details on the Projects page.

Subary Legacy BE/BH factory satnav and climate replacement

This is a copy of a post I wrote on the Club Sub forums.

Here’s how to replace a Subaru OEM “FM Hybrid Navigation System” included in many JDM BE and BH Legacys (MY1998-2003). This unit also functions as a display for the HVAC (heating, ventilation and air conditioning) controls so it’s a pain if you want to rip it out or don’t have the firmware CD (I have a working image of this if you need it BTW).

The good new is you can replace it with the standard auto climate panel. Note that all the mechanics and wreckers I’ve spoken to say this can’t be done; however it can and I have! It took a bit of hacking and research, and I’ve never found any instructions on it anywhere so I’ve written this in case you want to have a go yourself. Unfortunately I didn’t take the photos until afterwards so there aren’t many.



Before I start, I should mention that if you modify your car it is at your own risk. I am not to be held responsible for any damage or injury caused as a result of using the information in this post. It has worked well for me but there may be variations between models, etc.

Stuff you will need (read notes!)

  • Auto climate control unit part 72311AExxx (xxx can be 000, 100, 170 or 180)
  • Plugs to fit above unit with a few inches of cable attached
  • Stereo mounting brackets to suit above unit
  • Suitable dash surround
  • Dash air sensor for 170/180 units
  • #1 Phillips screwdriver
  • #1 Phillips stubby
  • Plastic wedge/flat blade screwdriver/butter knife for unclipping the fascia
  • Soldering iron and solder
  • Heatshrink tubing (approx 4mm dia)
  • Black PVC insulation tape (use good stuff like Nitto)

First, some important notes. It seems there are several different types of ‘standard’ (i.e. non-satnav) climate panel available; 000, 100, 170 and 180. There may even be others for all I know. The 030 is the satnav-style one. The 000 and 100 were used from 1998 to 2000 and have a built-in air temperature sensor. I’ve no idea what the difference between the two is.

The 170 and 180 were used from 2001 to 2003 and have a separate air sensor located in the dash surround. I’m not sure what the official difference between them is but I do know the 180 doesn’t beep when you press buttons and doesn’t seem to be quite compatible with the 170 wiring loom. Maybe someone else here can explain in better detail.

I replaced my old 030 with a 170 and it works fine. I have no idea what to expect with the others but can’t see why they wouldn’t work either; I doubt Subaru engineers would make significant changes to the electrical specs as it would just cost them money.

Whatever type you choose, make sure you get the plugs and wiring to match that same part number! They all physically fit the same but I’ve been warned by my mechanic that Subaru had a habit of changing the pins around with each model.

Shop around too; try TradeMe, eBay and various wreckers as prices vary widely. I was originally quoted between $220-$300 but in the end I got mine from RPM Garage for US$55.

The other thing to note is the dash fascia. Obviously to save money you could just replace the fascia around the stereo with one of a matching colour. Mine was fake wood grain so I decided to go the whole hog and replace the entire kit (transmission shift fascia, stereo fascia, drink holder and lighting control panel) with a smarter black brushed aluminium look. Note you will need to find a shift fascia that matches your transmission type.

If you use a 170 or 180 controller you will need the surround that has an air temperature sensor on it. It’s probably easiest to visit a wreckers in person so you can hand pick all the bits you need.


There is a nice post with photos on getting things apart here. I’ve described it anyway.

First up you should disconnect the battery ground.

The transmission fascia simply unclips. Start by carefully lifting the handbrake end straight up until it pops off, then gently pull the fascia towards the rear of the car until the top two clips pop out. Manuals you will need to unscrew the gear shift knob, autos you need to unplug the mode switch.

Remove the two screws on the accessory tray and lift it out.

Remove the ash tray. There are two screws under the stereo fascia where the ash tray sits; remove these.

The stereo fascia simply pulls out. You will need to run a flat object around the sides to help unclip everything. I use a stainless butter knife wrapped in PVC tape for this to prevent damage to the dash. The drink holder and climate buttons come out with the fascia.

Disconnect any plugs from the fittings on the fascia and the air temperature sensor hose.

Undo the screw below the air vents and gently pop the air vent panel out slightly to make room for the next step.

Undo the six screws on the stereo brackets and remove the stereo/satnav assembly. It’s quite heavy and there are a lot of plugs to disconnect! Be careful not to knock the sharp metal brackets on the dash as it scratches very easily.

The climate system consists of three units; a beige box on top of the satnav unit, the satnav unit itself and the button panel. The beige box is the HVAC computer; this is almost identical inside to the standard climate unit sans the buttons and display.

Identify the plugs to each of the units. There are two grey ones to the HVAC computer, a black one to the control panel and another black one to the satnav unit.

Here comes the fun part. Remove the tape from the above four looms all the way back to where they join to the stereo loom. You will notice that there are a lot of wires that link the units; two (black and brown) between the HVAC computer and the satnav and quite a few more between the beige box and control panel.

Cut each wire one at a time (except the looped ones) and connect the replacement plugs as shown in the chart below. Solder and heatshrink each connection for the best reliability. I recommend labeling each one as you go so you can easily revert it all if the mod doesn’t work. There will be quite a few spare wires left over; heatshrink any spare ends to prevent shorting. Note the two light blue wires that need to be joined together.

Pin numbers are per the service manual and match those with the 170 I used. Most will have some pin numbers on them, but to identify them anyway hold the plug with the retainer clip facing up and the wires facing away from you. The pins are numbered from left to right, top to bottom. For example, a 16 pin plug will be numbered like this:

1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16

Photo of 20 pin plug:

Wiring Layout

Replacement unit
Plug A (black) – 16 pins
Plug B (black) – 20 pins

Old units
Climate control computer
Plug C (grey) – 22 pins
Plug D (grey) – 26 pins

Control panel
Plug E (black) – 20 pins

Satnav unit
Plug F (black) – 6 pins

Anything italics doesn’t have to be reconnected, I’ve just provided them for reference.

Old New Colour Purpose
C1 A1 Blue/Red +12V Battery
C2 A2 Green/Blue +12V Ignition
C3 A3 Yellow/Red +12V Accessory
C4 A4 Green/Red Sunload Sensor
C5 A5 White/Red Heater
C6 A6 White/Green Heater
C7 N/C Purple Illumination
C8 A7 Yellow A/C Clutch Relay
C9 A8 Blue/White Heater
C10 B1 Green/Yellow Heater
C11 B2 L. Green/White Blower
C12 A9 Black Ground
C13 A10 Sky Blue Sensor Ground
C14 N/C Black/Yellow Illumination ground?
C15 A11 Orange Ambient Sensor
C16 A12 Brown/White Blower
C17 A13 Pink/White Ext. Thermometer
C18 A14 White/Orange Heater
C19 N/C Brown/Yellow Ground (diagnostics?)
C20 A16 Red/Black Heater
C21 B11 Yellow/Blue Heater
C22 B12 Black/Blue Blower
D1 B3 Violet/Yellow Blower Relay
D2 B5 Red/Yellow Blower
D4 Loop Brown/Black Data to Satnav
D6 B8 Green/White Diagnostics
D7 B7 Blue/Orange Diagnostics
D8 Loop Black/Red Control Panel
D9 Loop Brown Control Panel
D10 Loop Blue/Yellow Control Panel
D11 Loop Red/Black Control Panel
D12 Loop White Control Panel
D13 Loop Yellow/Black Control Panel
D14 B13 Violet/Green Demist Relay
D15 B15 Pink/White ECU
D16 B16 Green/Black Speed Sensor (MT)/TCU (AT)
D17 Loop Black/White Data Gnd to Satnav
D20 B17 L. Green/Red Diagnostics
D21 Loop White/Black Control Panel
D22 Loop Red Control Panel
D23 Loop Brown/Red Control Panel
D24 Loop White/Red Control Panel
D25 Loop Red/White Control Panel
D26 Loop Blue/Black Control Panel
E1 N/C Blue/Green +12V Ignition
E3 N/C Black/Yellow Illumination ground?
E4 Loop White/Black Climate Computer
E5 Loop Blue/Yellow Climate Computer
E6 Loop Red/Black Climate Computer
E7 Loop White Climate Computer
E8 Loop Red/White Climate Computer
E9 A10 Sky Blue Sensor Ground
E10 B20 Black Illum. Ground
E11 B10 Violet Illumination
E13 Loop Black/Red Climate Computer
E14 Loop Red Climate Computer
E15 Loop Brown/Red Climate Computer
E16 Loop White/Red Climate Computer
E17 Loop Yellow/Black Climate Computer
E18 Loop Blue/Black Climate Computer
E19 A15 Black Ground
E20 Loop Brown Climate Computer

F – None used. The Yellow/Violet wire is 12V accessory and a handy tap if you have a band expander as it saves chopping the stereo wiring.

Double check your work before reconnecting the battery!


Hold down the Auto and Recirculate buttons while switching on the ignition. The climate unit will flash a test display (all symbols on) and beep four times. After that it will display a troubleshooting code. If it says 20 then all is well so far. If it says 25 you probably have your car in the shade; try parking it in sunlight. If anything else then double check your wiring. Here’s a list of possible trouble codes:

Press Defrost to begin the self-test cycle. The unit will cycle through a variety of tests and display the number of each test as it runs. Check that everything operates as shown in the test chart below. If this all works OK, ensure the engine starts normally and no fault lights appear.


The GPS antenna is located behind the instrument cluster. If you want to remove it you will need to take the instruments out first. I left mine in there.

The CeNet and video cable go under the driver kick panel and end up under the drivers seat where there is a TV tuner module stuck to the carpet with Velcro. I removed all of this intact as it it quite simple.

Now you can tape up the looms, put it all back together and enjoy your new climate unit!

Safe driving!