For automotive enthusiasts and DIY mechanics looking to delve deeper into vehicle diagnostics, especially for models like the 2008 Ford Taurus X, understanding and accessing different Controller Area Networks (CAN) is crucial. While standard ELM327 OBD2 adapters are widely used for reading engine codes and basic data, they often fall short when it comes to accessing the full spectrum of your vehicle’s systems. This article guides you through modifying a budget-friendly ELM327 clone to unlock Medium Speed CAN (MS-CAN) functionality, significantly expanding your diagnostic capabilities for Ford vehicles, including the 2008 Ford Taurus X.
Before 2004, OBD-II systems in vehicles primarily utilized the SAE J1850 PWM protocol. However, modern vehicles, particularly those with digital instrument clusters (common in models like the 2008 Ford Taurus X), adopted CAN bus technology. For Ford and Mazda owners, tools like FORScan offer powerful diagnostic capabilities. But to fully leverage FORScan and access modules beyond the engine control unit, modifying your ELM327 for MS-CAN support becomes a game-changer.
Understanding CAN Bus: HS-CAN and MS-CAN
You might be wondering, “What exactly are HS-CAN and MS-CAN?” CAN, or Controller Area Network, is essentially a digital communication network within your car. Think of it as a local network (LAN) connecting various computer modules, similar to how devices connect in your home or office. This network allows modules to share data and enables comprehensive diagnostics and troubleshooting beyond just engine-related issues. Accessing this network empowers you to diagnose problems within systems like the Anti-lock Braking System (ABS), airbags, climate control, and more, all from the convenience of your own garage using affordable tools.
Historically, accessing this intricate vehicle network required expensive, professional-grade scan tools and specialized software. However, the landscape has shifted dramatically. Now, for as little as $10, you can modify a cheap ELM327 adapter and gain access to a wealth of diagnostic information previously unavailable to the average user.
In most vehicles manufactured before 2013, including the 2008 Ford Taurus X, you’ll find two primary CAN buses:
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HS-CAN (High-Speed CAN): This network is dedicated to time-sensitive, critical data. It handles priority communications related to engine management (PCM), safety-critical systems like ABS and Restraint Control Module (RCM – airbags and seatbelts), and other essential functions.
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MS-CAN (Medium-Speed CAN): MS-CAN manages less time-critical but equally important functions within the vehicle’s interior and comfort systems. This includes modules controlling the radio, climate control, lighting, body control functions, and more. For owners of a 2008 Ford Taurus X experiencing issues with interior electronics, MS-CAN access is invaluable.
In newer vehicles (2013 and onwards), the complexity of vehicle systems has increased significantly, leading to an expansion of the CAN network. These vehicles often utilize four CAN buses (three HS-CAN and one MS-CAN) to manage the increased data flow. Virtually every function, from headlight switches and door controls to seat adjustments and dashboard buttons, communicates over the CAN bus.
It’s important to note that the HS-CAN and MS-CAN buses are bridged within the Instrument Panel Cluster (IPC). This bridging allows data to be exchanged between the networks as needed, ensuring seamless communication across different vehicle systems.
To give you a clearer picture, here’s a breakdown of typical modules found on HS-CAN and MS-CAN in vehicles like the 2008 Ford Taurus X:
HS-CAN Modules:
- PCM (Powertrain Control Module)
- ABS (Anti-lock Brake System, including AdvanceTrac and Traction Control)
- RCM (Restraint Control Module, AKA airbags and seatbelts)
- AWD (All Wheel Drive module, if equipped)
- OCSM (Occupant Classification System Module, AKA Passenger Seat Sensors)
- PAM (Parking Aid Module)
- IPC (Instrument Panel Cluster)
- PSCM (Power Steering Control Module, Hydraulic Power Steering only)
- SECM (Steering Effort Control Module, Electric Power Steering only)
- CCM (Cruise Control Module)
- APIM (Accessory Protocol Interface Module AKA SYNC)
MS-CAN Modules:
- SJB/BCM (Smart Junction Box/Body Control Module)
- HVAC (Heating, Ventilation & Air Conditioning module)
- ACM (Audio Control Module)
- DSP (Audio Digital Signal Processing Module)
- DSM (Driver Seat Module)
- DDM (Driver Door Module)
- RFA (Remote Function Actuator Module)
- DCSM (Dual Climate Controlled Seat Module)
- SDARS (Satellite Digital Audio Radio Service)
- FCIM (Front Controls Interface Module)
- FDIM (Front Display Interface Module)
- ILCM (Interior Lighting Control Module)
- HCM-2 (High Beam Control Module)
- SOD-R/L (Side Obstacle Detection Control Module AKA BLIS, one module for each side)
- IPC-MS (Instrument Panel Cluster – MS-CAN side)
- GPSM (Global Positioning System Module)
- APIM (Accessory Protocol Interface Module AKA SYNC – MS-CAN side in some configurations)
Keep in mind that module configurations can vary across different Ford models and model years. For a detailed visual representation of module connections, you can refer to diagrams like this one from a 2011 Ford vehicle: http://revbase.com/BBBMotor/Wd/DownloadPdf?id=875110
Modifying Your ELM327 Adapter for MS-CAN Access: A Step-by-Step Guide
Many automotive enthusiasts and DIYers utilize affordable ELM327 clones purchased online. Out of the box, these clones are typically configured to only communicate over HS-CAN, limiting their diagnostic capabilities. However, some newer scan tools equipped with STN1170 chips natively support MS-CAN (and GM single-wire CAN), eliminating the need for modification. Check your device specifications to see if you already have MS-CAN support.
For those with standard ELM327 clones, modifying the device to enable MS-CAN access is a straightforward process. You’ll need a dual-position, dual-pole (DPDT) switch. This switch will allow you to toggle between connecting the ELM327 chip to either the HS-CAN or MS-CAN terminal pairs in your vehicle’s Diagnostic Link Connector (DLC), commonly known as the OBD2 port.
Image showcasing a Double Pole Double Throw (DPDT) switch, essential for modifying an ELM327 adapter to switch between HS-CAN and MS-CAN.
The following instructions, adapted from forscan.org, outline the modification process:
Step 1: Disassemble Your ELM327 Clone.
Carefully open your ELM327 device. Typically, you’ll find four screws located beneath the sticker. Remove these screws to access the internal components.
Step 2: Disconnect and Desolder HS-CAN Wires.
Unplug the OBD-II connector from the circuit board if it’s detachable. Identify and desolder the wires connected to pins 6 and 14 on the OBD-II connector. These are the original HS-CAN wires. Crucially, mark these wires so you can easily identify them later.
Step 3: Solder New Wires to HS-CAN Pins.
Solder two new wires to pins 6 and 14 on the OBD-II connector. These new wires will eventually connect to the switch and carry the HS-CAN signal.
Step 4: Solder New Wires to MS-CAN Pins.
Solder another two new wires to pins 3 and 11 on the OBD-II connector. These wires will be used for the MS-CAN connection and will also connect to the switch.
Step 5: Connect Original HS-CAN Wires to the Switch.
Solder the wires you originally desoldered from pins 6 and 14 (the marked HS-CAN wires) to the two center poles of the DPDT switch.
Step 6: Connect New HS-CAN Wires to the Switch.
Solder the new wires you attached to pins 6 and 14 in Step 3 to one side of the DPDT switch. Ensure correct polarity by matching pin 6 wire to the terminal connected to the original pin 6 wire on the center pole, and similarly for pin 14.
Step 7: Connect New MS-CAN Wires to the Switch.
Solder the new wires connected to pins 3 and 11 (from Step 4) to the other side of the DPDT switch. Again, maintain polarity. Connect the wire from pin 3 to the terminal associated with the original pin 6 wire (for polarity consistency), and the wire from pin 11 to the terminal associated with the original pin 14 wire.
Important Polarity and Wiring Considerations:
- Do not mix up HS-CAN and MS-CAN wires.
- Strictly observe polarity. Incorrect wiring can lead to damage.
- Using different colored wires for HS-CAN and MS-CAN (e.g., red for HS-CAN, black for MS-CAN) can help prevent confusion during wiring.
Refer to these diagrams for a visual guide to the wiring: (Note: Diagrams show the dash connector view, reverse for the scan tool view!)
Diagram illustrating the wiring configuration for modifying an ELM327 adapter to incorporate a switch for HS-CAN and MS-CAN selection.
Pinout diagram of a Ford OBD2 connector, highlighting the positions of HS-CAN and MS-CAN pins for accurate wiring during ELM327 modification.
Visual Walkthrough of the Modification Process:
The following images provide a visual guide through the modification steps and showcase the final modified ELM327 adapter:
Image showcasing the internal motherboard of an ELM327 adapter, providing a visual reference for users undertaking the modification process.
Image of wires soldered to OBD-II connector
Close-up image detailing the soldering of wires onto the OBD-II connector of the ELM327 adapter, a crucial step in the MS-CAN modification.
Image displaying the DPDT switch installed within the ELM327 adapter housing, allowing for manual selection between HS-CAN and MS-CAN modes.
Image of components inside the ELM327 housing
Image showing the modified components neatly placed back inside the ELM327 adapter housing before final reassembly, demonstrating a clean and organized modification.
Image of finished modified ELM327
Image of the completed, modified ELM327 adapter, now equipped with MS-CAN capability, ready for enhanced vehicle diagnostics.
Accessing MS-CAN with FORScan: Unleashing the Full Potential
Once you’ve modified your ELM327 adapter, you can utilize software like FORScan to access the MS-CAN network on your 2008 Ford Taurus X and other compatible Ford vehicles.
Here’s how to configure FORScan:
When you launch FORScan after modifying your adapter, the software should detect the modification and ask: “MS/HS CAN Switch?”: Select “YES.”
Screenshot of FORScan software prompting the user to confirm the presence of an MS/HS CAN switch, a key step in utilizing the modified ELM327 adapter.
You might need to delete your car’s profile in FORScan, close and reopen the program, and then reconnect to your vehicle for the prompt to appear consistently. Some users report needing to repeat this step each time they use FORScan.
With the MS/HS switch enabled in FORScan, you can now perform a wider range of diagnostic tests and access modules that were previously inaccessible via standard ELM327 adapters limited to HS-CAN. This includes running self-tests and reading data from both HS-CAN and MS-CAN modules, significantly expanding your diagnostic capabilities for your 2008 Ford Taurus X and other Ford vehicles.
Screenshot of FORScan module list
Screenshot from FORScan displaying an extensive list of modules accessible via both HS-CAN and MS-CAN, showcasing the enhanced diagnostic capabilities after ELM327 modification.
By modifying your ELM327 adapter, you gain access to a wealth of diagnostic information for your 2008 Ford Taurus X and other Ford vehicles, empowering you to troubleshoot a wider range of issues and gain a deeper understanding of your vehicle’s systems. Download FORScan today from FORSCAN.org and unlock the full diagnostic potential of your Ford.
