The green unit appears to be a modern OEM DENSO TEN/Toyota-family multimedia platform, but the photographs do not expose the external radio model, Toyota/DENSO part number, FCC ID, donor vehicle, or software model string. Those identifiers are required before any exact firmware or connector map can be trusted.
The most important correction for the vehicle side is that a 2007 Chrysler Town & Country does not use the later two-wire CAN-IHS radio network. Its radio participates in Chrysler's older single-wire PCI bus, identified in Chrysler documentation as circuit D25 and commonly associated with SAE J1850 VPW signaling. Therefore the green head unit cannot be connected directly to the van's data wire. It needs a protocol gateway that translates Chrysler PCI messages into the donor head unit's expected CAN/LIN/hardwired signals.
Android Auto: likely situation
The presence of working Apple CarPlay proves that the head unit already has several hardware resources Android Auto would also need: a USB path, display/compositor path, audio path, microphone path, Bluetooth/Wi-Fi hardware, and projection software infrastructure. The visible MT7902 family radio is a 1x1 Wi-Fi 6E plus Bluetooth/BLE device.
However, same PCB does not mean Android Auto can be enabled with one test pad. OEM tiers commonly differ through:
Signed firmware packages
Feature/vehicle configuration stored in secure or calibration memory
Region and model manifests
USB hub/port configuration
Projection certificates and Google/OEM licensing
Vehicle VIN or ECU provisioning
Backend entitlement or dealer configuration
Different software partitions despite identical hardware
Ranked enablement paths
Correct official firmware for the exact part number — safest route. Toyota/DENSO service bulletins show that these systems accept model-specific USB update packages. Installing firmware for a visually similar but different variant can brick the unit or disable audio, cameras, display, and vehicle networking.
OEM diagnostic configuration — possible if Android Auto is present in the image but disabled by a model/region/grade flag. This requires the exact donor vehicle, service tool, and configuration identifiers.
Swap the complete storage/module or main board from the higher tier — often more realistic than cross-flashing if software is signed and hardware identifiers are checked.
External Android Auto receiver — a separate wired/wireless Android Auto interface feeding an existing AUX/video/USB path. This avoids modifying secure OEM firmware but needs compatible display/touch/audio injection.
Firmware reverse engineering — last resort. It requires boot logs, storage identification, update-package analysis, and a recoverable full backup. Secure boot may make modified firmware impossible to run.
Do not flash a higher-tier image until the full model identifiers and a recovery method are known.
What LINUX-SW probably means
A pad marked LINUX-SW most likely means Linux switch, a manufacturing/service boot strap sampled by the processor or companion MCU. Possible functions include:
Requesting a Linux recovery or factory-test boot
Selecting a production diagnostic image
Changing boot source or console behavior
Entering update/download mode
Holding a GPIO state for automated fixture tests
It does not imply a general-purpose Linux interface, extra operating system, or automatically unlocked shell. The pad could be active-low, active-high, analog-coded, checked only at reset, or connected through a resistor network. Driving it blindly can hold the unit in reset, start destructive factory provisioning, or trigger a flash erase.
Safe method for identifying LINUX-SW
With power disconnected, measure resistance from the pad to ground and all nearby rails.
Trace continuity through nearby resistors to the processor, MCU, or connector.
Power normally and measure idle voltage during OFF, wake, boot, and running states.
Capture the suspected UART console during normal boot.
Only then test the switch through 10 kOhm, first to ground and later to the confirmed logic rail, while current-limited and able to recover power.
Test only during reset/boot and record changes in UART output.
Never short the pad directly to 12 V, battery ground, or an unverified VCC pad.
Why there are so many labeled footprints
Modern OEM infotainment boards are designed for multiple trims, regions, factories, and service procedures. The extra pads and unpopulated connectors typically serve:
ICT/flying-probe production testing
Boundary scan and processor debugging
Bootloader and flash programming
Calibration of radio, display, camera, GNSS, and audio
Optional tuner, modem, satellite-radio, or amplifier variants
Engineering-only serial consoles
Power-rail and clock measurements
Panel/display variants
Factory end-of-line tests
Most reference marks such as CNxxxx, ICxxxx, Rxxxx, Cxxxx, 1/4, 2/4, LF, KD, and SYS identify components, assemblies, or manufacturing sections—not usable external signals.
Interfaces worth investigating
Table
Interface
What it can provide
How to recognize it
Initial connection
UART console
Bootloader/Linux logs, software versions, device failures, possibly a shell
One idle-high TX pin with bursts during boot; usually 1.8 or 3.3 V
Board TX to level-compatible adapter RX through 1–4.7 kOhm; common GND; leave adapter TX disconnected
JTAG/SWD/proprietary debug
Halt/debug/programming if security permits
Clock/data/reset/VREF cluster near SoC or MCU
Do not connect until exact processor suffix and pin map are known
USB host/device
Phone projection, updates, diagnostics
90-ohm differential D+/D- pair, ESD parts, USB switch/hub
Use the original USB port or identify the hub; do not tack long wires onto high-speed pairs
CAN
Donor-vehicle messages
Two matched traces into a CAN transceiver, commonly 60 ohm across H/L in a terminated network
Isolated CAN interface; first sniff passively at candidate rates
LIN
Single-wire local peripheral control
One protected single wire into a LIN transceiver
LIN interface, not TTL UART
I2C
Audio/display/tuner configuration
SCL/SDA pair with pull-ups and short bursts
Logic analyzer after measuring 1.8/3.3 V level
SPI
Flash/peripheral control
Clock, chip-select, MOSI, MISO
Passive capture first
I2S/TDM
Digital audio injection/capture
MCLK/BCLK/LRCLK/data signals
High-impedance analyzer; establish clock ownership and voltage first
Display FFC
MIPI/LVDS/eDP or proprietary panel interface
Multiple tightly coupled differential pairs plus backlight/control
Requires exact panel model and connector pinout
2007 Chrysler Town & Country integration
Factory radio environment
The 2007 van uses a 22-pin Chrysler radio connector family. Public pinout material identifies typical functions including:
Constant battery power
Switched accessory power
Chassis ground
Panel illumination
Four speaker pairs
Amplifier/radio control output where equipped
Single-wire PCI bus
The Chrysler PCI network is not ordinary UART and is not two-wire CAN. Documentation for the same RS/RG platform describes an idle state near 0 V, transmitted pulses rising to roughly 7.5 V, and approximately 10.8 kbit/s average signaling. Directly connecting it to the green unit's CAN, LIN, or MCU pins would likely damage hardware.
Required gateway architecture
The practical installation should use a custom or commercial interface with:
Chrysler PCI/J1850-VPW physical-layer transceiver — protected connection to the van's single-wire D25 bus.
Gateway MCU — decodes vehicle messages and generates the donor radio's expected messages or discrete outputs.
Donor-radio network interface — usually isolated/protected CAN, possibly LIN and discrete wake/ACC lines; exact choice depends on the green unit's source vehicle.
Automotive power front end — fuse, reverse-polarity protection, load-dump/transient protection, filtered permanent B+, and switched/wake control.
Audio adaptation — direct speaker outputs only if the green unit contains a suitable amplifier; otherwise balanced/line-level adaptation to the Chrysler factory amplifier or an aftermarket amplifier.
USB, microphone, camera, antenna, and steering-wheel adapters — handled independently from the data gateway.
Signals the gateway should expose
Table
Van information
Source
Green-unit output/action
Ignition/RAP
Hardwired ACC and/or PCI
ACC/wake and delayed shutdown
Illumination/dimmer
Hardwired panel-lamp signal or PCI
Illumination input or CAN message
Reverse
Reverse-lamp circuit or PCI
Reverse trigger and camera selection
Parking brake
Hardwired brake switch via safe isolated sensing
Parking state input
Vehicle speed
PCI message or conditioned VSS if available
VSS pulse or donor CAN message
Steering-wheel buttons
BCM sends button events on PCI
Donor CAN messages, analog KEY ladder, or USB HID depending on head unit
Factory amplifier enable
PCI plus remote output
Amplifier wake/enable
Door/vehicle status
PCI
Optional display integration only
Safer first integration stage
Do not begin by translating the whole vehicle bus. Bring the green unit up using only:
Permanent fused B+
Ground
Controlled ACC/wake
Illumination
Reverse trigger
External speakers or a known amplifier
USB phone port and microphone
Once the unit boots and CarPlay works on the bench, passively record the donor CAN traffic needed for startup. Then add Chrysler PCI decoding for steering controls and vehicle state.
What can realistically be achieved
High probability
Bench operation
CarPlay through the original USB/wireless hardware
Audio output
Microphone
Reverse camera switching
Illumination/day-night control
Steering-wheel controls through a gateway
Chrysler ignition/RAP integration
Medium probability
Android Auto through correct OEM firmware or higher-tier board/storage swap
Vehicle speed, reverse, and parking state through a gateway
Factory amplifier retention
UART boot-log capture
Service/recovery mode discovery through LINUX-SW
Low probability without OEM engineering material
Arbitrary Linux shell/root access
Running unsigned modified firmware
Reusing every FFC or production test connector
Enabling higher-tier functions solely by grounding one pad
Complete emulation of the donor vehicle's network without capturing a working donor installation
Information still required for an exact plan
Provide clear photos of:
The complete external product label and barcode sticker on the green radio chassis.
Every rear connector and its keying.
The on-screen Settings > Software update > Model information page.
The donor vehicle's year, make, model, trim, screen size, and whether it had JBL/premium audio.
The exact location and close-up of the LINUX-SW label, with nearby parts readable.
Your Town & Country's factory radio sales code and whether it has the Infinity amplifier, steering-wheel buttons, rear DVD, and factory camera.
Without the donor identity, Android Auto firmware selection and donor-CAN emulation remain blocked because visually identical boards can require incompatible signed images and network messages.