Ensuring the correct installation of telematics devices in vehicles is crucial for accurate data collection and vehicle performance monitoring. For many modern vehicles, this process involves utilizing the On-Board Diagnostics II (OBD2) port, a standardized interface providing access to a wealth of vehicle data. This guide will help you understand the OBD2 port, its importance in telematics installation, and how to select the appropriate harness for your vehicle, including specific considerations for vehicles like E-ONE fire trucks.
Vehicle Assessment: Identifying Your Harness Needs
Before installing any telematics device, a thorough vehicle assessment is essential. This involves gathering key information to determine the correct harness and ensure seamless connectivity. Follow these steps to prepare for your installation:
-
Vehicle Information Request: Obtain a comprehensive vehicle list from your customer, including:
- Vehicle Identification Number (VIN)
- Manufacturer
- Model
- Year of manufacture
-
Harness Lookup Preparation: Utilize a harness lookup tool or spreadsheet to organize vehicle data.
- Verify data completeness and accuracy, ensuring no missing or incomplete entries.
- Standardize manufacturer and model names for consistency (e.g., “F-150” instead of “F150”).
- Summarize vehicle types and quantities for efficient planning.
-
Compatibility Table Consultation: Refer to vehicle compatibility tables to pinpoint the specific harness requirements for each vehicle based on the collected data. These tables, like the ones provided below, are vital resources for accurate harness selection.
Vehicle Type and OBD2 Port Considerations
Light-Duty Vehicles and the OBD2 Standard
Since 1997, most light-duty vehicles are equipped with a standardized 16-pin OBD2 port. This standardization simplifies telematics device installation, often allowing the use of universal harnesses like the HRN-BS16S4, HRN-BS16S4F, or the HRN-GS16K22-A universal T-Harness. However, it’s important to consult compatibility tables for specific exceptions and vehicle requirements.
Note: Modern telematics devices like the GO9 often feature a 16-Pin Port, potentially eliminating the need for a separate harness in some light-duty vehicle installations.
Heavy-Duty Trucks and Diagnostic Port Variety
Heavy-duty trucks, from manufacturers like Freightliner, International, Kenworth, Mack, Peterbilt, Volvo, and Western Star, may present a wider range of diagnostic port types. While many utilize OBD2 ports, others may feature different connectors like 6-pin, 9-pin, or RP1226 ports. Careful assessment and the use of compatibility tables are crucial for these vehicle types.
GO RUGGED and Specialized Harnesses
For rugged environments and off-road applications, GO RUGGED devices are recommended. These devices often require specific harnesses tailored to the harsh conditions and vehicle types they are used in. Always refer to specific documentation for GO RUGGED harness compatibility and installation procedures.
Diagnostic Port Types: OBD2 and Beyond
Telematics installations may encounter both OBD2 and RP1226 diagnostic ports. While OBD2 is standard for many light-duty and some heavy-duty vehicles, RP1226 is more common in heavy-duty applications.
It’s critical to note a regulatory consideration regarding the California Air Resources Board (CARB). CARB regulations may restrict the use of RP1226 connectors for certain data access required for programs like the Clean Truck Check (CTC) in California. For vehicles operating in California and subject to CTC, OBD2 port connections are generally preferred to ensure compliance.
VIN Decoding for Vehicle Specification
In situations where only the VIN is readily available, online VIN decoding tools can be invaluable. These sites allow you to retrieve essential vehicle details such as Make, Model, and Year, streamlining the harness selection process when a full vehicle list isn’t immediately accessible.
Harness Compatibility and Important Considerations
Crucial Warning: Always use Geotab-approved harnesses sourced from authorized channels. Using non-Geotab harnesses can create serious safety hazards, including fire risks, potentially leading to vehicle damage or personal injury.
Harness Compatibility Disclaimer: Geotab strives to provide accurate harness compatibility information. However, due to the complexity of vehicle configurations, potential aftermarket modifications, and limited vehicle-specific data, Geotab cannot guarantee harness compatibility in every situation. Professional installation by an Authorized Installer is strongly recommended.
For assistance in determining the correct harness for a specific vehicle, always consult with an Authorized Installer or Geotab Support.
Compatibility Tables: Detailed Harness Information
The following tables provide detailed harness information categorized by vehicle type and manufacturer. These tables are essential for identifying the correct straight harness or T-harness for various makes, models, and years.
Light-Duty Vehicle Harnesses
All Makes / Models (Light-Duty)
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| All |
All |
HRN-CW03K3 |
|
Any vehicle without a diagnostic port. |
| All light duty |
All |
1997+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Applies to all light duty makes and models. See exceptions below. |
Ford Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Ford |
F150–F550 |
1997+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
|
| Ford |
F650+ |
1997+ |
HRN-DS09S4 HRN-BS16S4 HRN-DS06S4 |
HRN-GS09K2-A HRN-GS16K22-A HRN-DS06T2-A |
If the vehicle has a Ford Engine, use the 16-pin harness HRN-GS16K22-A. For non-Ford Engines, use either the 6-pin harness HRN-DS06S4 or 9-pin harness HRN-GS09K2-A. Be sure to confirm the vehicle diagnostic port before purchase. |
| Ford |
Fiesta |
1997+ |
Must use T-harness |
HRN-GS16K22-A |
Must use T-harness due to the location of the diagnostic port. The 2017+ Mk7 models can be directly plugged into the diagnostic port. |
| Ford |
Fusion |
1997+ |
Must use T-harness |
HRN-GS16K22-A |
Must use T-harness due to the location of the diagnostic port. |
Dodge Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Dodge |
All |
1997+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII before ordering the harness. |
General Motors (GM) / Chevrolet / GMC Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| GM/Chevy |
All light-duty GM/Chevy cars/trucks (e.g. Cruze, Malibu, Silverado, Sierra, etc.) |
1997+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII before ordering the harness. |
| Chevrolet |
C4–C7 & T6–T8 Series |
2006–2009 |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII before ordering the harness. |
| GMC |
C4–C8 & T6–T8 Series |
2006–2009 |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII before ordering the harness. |
Nissan Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Nissan |
Frontier |
1997+ |
Must use T-harness |
HRN-GS16K22-A |
Must use T-harness due to the location of the diagnostic port. |
| Nissan |
UD |
2009 |
HRN-DS09S4 |
HRN-GS09K2-A |
!**IMPORTANT: The vehicle has two diagnostic ports — do not connect to the OBDII port.** |
Isuzu Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Isuzu |
All |
1997+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII before ordering the harness. If not, use HRN-CW03K3 instead. |
| Isuzu |
Diesel N-series vehicles with RPO code I4H (will be listed on the sticker located on the door jamb). Applies to North America vehicles only. |
2017+ |
N/A |
HRN-CM24Y1-A + HRN-CI04A2 |
The optional Isuzu FMS port provides features required for ELD solutions, such as odometer, which are not provided by HRN-GS16K22-A. Requires HRN-CM24Y1 (from Geotab) and FMS kit (CAN converter), which, if not ordered at time of manufacture, must be ordered and activated through an Isuzu dealer. |
| Isuzu |
F-series |
2022+ |
N/A |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII prior to ordering the harness. If 9-pin diagnostic port on vehicle, order the HRN-GS09K2-A harness. |
Hino Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Hino |
All |
1997-2013 |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
The vehicle has two diagnostic ports. Data typically comes through the 16-pin but in some cases the 9-pin. |
| Hino |
200-500 Series |
2014-2018 |
|
Universal 16-pin Harness HRN-GS16K22-A OR Adapter harness HRN-CM24Y1-A + HRN-CH06A2 |
Use either the universal 16-pin harness or the special adapter harness. Note that data on the diagnostic port may be limited. |
| Hino |
100 Series |
2014-2018 |
|
Universal 16-pin harness HRN-GS16K22-A OR Adapter harness HRN-CM24Y1-A + HRN-CH10A2 |
Use either the universal 16-pin harness or the special adapter harness. Note that data on the diagnostic port may be limited. |
| Hino |
All |
2019+ |
|
Universal 16-pin harness HRN-GS16K22-A OR Universal 9-pin harness HRN-GS09K2-A OR Adapter harness HRN-CM24Y1-A + HRN-CH10A2 |
|
Mercedes-Benz Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Mercedes |
All |
1997+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
|
| Mercedes |
Sprinter |
2019+ |
HRN-CP04K2 + HRN-CM24Y1 (for PSM connection) |
N/A |
For 907 and 910 chassis only. This harness is only required if you are connecting to the PSM module instead of the OBD port (for example, if the OBD port is already being used). Note that connecting to the PSM module is a more difficult install and does not provide any fault data or EV data. Therefore, if the OBDII port is available, we strongly recommend using a HRN-GS16K22-A in the OBD port instead. |
Mitsubishi Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Mitsubishi |
All Light Duty |
1997+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII before ordering the harness. |
| Mitsubishi Fuso |
All |
HRN-CW03K3 |
N/A |
Please use HRN-CW03K3 unless confirmed diagnostic port with Auxiliary port. If an Auxiliary port is present, use HRN-BU16Y5. |
| Mitsubishi Fuso |
All |
2010+ |
HRN-BU16Y5 |
N/A |
Must use HRN-BU16Y5. May require HRN-CW03K3 if no Auxiliary port is available. |
Workhorse Chassis Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Workhorse Chassis |
All |
1999+ |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
Please confirm that the diagnostic port is a 16-pin OBDII before ordering the harness. |
Electric Vehicle Harnesses
BYD Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| BYD |
All Bus Models |
All |
HRN-BS16S4 |
HRN-GS16K22-A |
Only applicable for BYD buses made in North America. For BYD buses made outside North America, please work with your Geotab Solutions Engineering team member and BYD person of contact to determine the appropriate harness to use. |
Tesla Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Tesla |
Model S |
September 16, 2015 or older |
HRN-CT06S2 |
N/A |
Please check the diagnostic connector of any MY2015 Model S prior to purchasing the harness. |
| Tesla |
Model S/X |
September 17, 2015 – 2021 |
HRN-CT06S1 |
N/A |
Please check the diagnostic connector of any MY2015 Model S prior to purchasing the harness. |
| Tesla |
Model S/X |
2022+ Plaid |
N/A |
HRN-CT06K1 |
Harness currently in Development |
| Tesla |
Model 3 |
2018 |
N/A |
HRN-CT20T1 |
The diagnostics port can be found in the rear behind the lower center console panel. |
| Tesla |
Model 3 |
2019-2023 |
N/A |
HRN-CT20T11 |
The diagnostics port can be found in the rear behind the lower center console panel. |
| Tesla |
Model 3 |
2024+ (Re-design) |
N/A |
HRN-CT06K1 |
Harness currently in development, expected to be ready in February 2025. |
| Tesla |
Model Y |
2019+ |
N/A |
HRN-CT26T1 |
The diagnostic port can be found in the rear behind the lower center console panel. |
Heavy-Duty Vehicle Harnesses
All Makes / Models (Heavy-Duty)
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| All |
All |
HRN-CW03K3 |
|
Any vehicle without a diagnostic port. |
| All Heavy Duty (see list above) |
All |
1997–1999 |
HRN-DS06S4 |
HRN-DS06T2-A |
|
Autocar Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Autocar |
All |
|
HRN-DS09S4 |
HRN-GS09K2-A |
|
Freightliner Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Freightliner |
All Medium Duty (i.e. M2 106 Medium Duty) |
2000+ |
HRN-DS09S4 or HRN-DS06S4 |
HRN-GS09K2-A or HRN-DS06T2-A |
Confirm if there is a 6-pin or 9-pin diagnostics port on the vehicle. |
| Freightliner |
All Heavy/Super Duty (ie. Cascadia, 114SD, 122SD & 108SD) |
2000–2012 |
HRN-DS09S4 or HRN-DS06S4 |
HRN-GS09K2-A or HRN-DS06T2-A |
Confirm if there is a 6-pin or 9-pin diagnostics port on the vehicle. |
| Freightliner |
All Heavy/Super Duty (ie. Cascadia, 114SD, 122SD & 108SD) |
2013+ |
Must use T-harness |
HRN-GS09K2-A |
Must use T-harness due to the location of the diagnostic port. |
| Freightliner |
All models |
2019+ |
HRN-CS14S21 |
HRN-CS14T2 |
Alternative if the vehicle is equipped with a 14-pin (RP1226) port. If the RP1226 port is not available, or if the vehicle is operating in California and part of the Clean Truck Check (CTC) program then use HRN-GS09K2-A with the diagnostic port. |
International Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| International |
7300–9900 |
2000–2005 |
HRN-DS06S4 |
HRN-DS06T2-A |
For MY2005, please check your diagnostic port prior to purchasing the harness. For International 7400, 2005 use HRN-DS09S4 and HRN-GS09K2-A. |
| International |
7300–9900 |
2006+ |
HRN-DS09S4 |
HRN-GS09K2-A |
|
| International |
5500i–9900i |
2000–2007 |
HRN-DS06S4 |
HRN-DS06T2-A |
Please check your diagnostic port prior to purchasing the harness. |
| International |
5500i–9900i |
2008+ |
HRN-DS09S4 |
HRN-GS09K2-A |
|
| International |
LT, RH, MV, HV, HX |
|
HRN-DS09S4 |
HRN-GS09K2-A |
Note: Vehicle may also be equipped with RP1226 port. In that case, use either HRN-CS14S21 or HRN-CS14T2. Please verify the port before ordering. |
| International |
CV Series |
2018+ |
HRN-BS16S4 |
HRN-GS16K22-A |
|
Kenworth Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Kenworth |
All |
2000–2016 |
HRN-DS09S4 |
HRN-GS09K2-A |
|
| Kenworth |
All |
2017+ |
Must use T-harness |
HRN-GS09K2-A |
For 2017+ model years, you must use a GO9 or newer. |
| Kenworth |
All models |
2019+ |
HRN-CS14S21 |
HRN-CS14T2 |
Alternative if the vehicle is equipped with a 14-pin (RP1226) port. If the RP1226 port is not available, or if the vehicle is operating in California and part of the Clean Truck Check (CTC) program, then use HRN-GS09K2-A with the diagnostic port. |
Mack Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Mack |
All |
2000–2012 |
N/A |
HRN-GS09K2-A |
|
| Mack |
All |
2013-2018 |
N/A |
Universal 16-pin harness HRN-CG13S1-A + HRN-GS16K22-A OR Adapter harness HRN-CM24Y1-A + HRN-CK10K2 |
If you are in California participating in the Clean Truck Check (CTC) Program, and there is a 16-pin diagnostic port, use the Universal Harness option. If you are not participating in the CTC, use the Adapter Harness. For more information, refer to the 2006-2018 Mack Install Guide |
| Mack |
All |
2019+ |
If RP1226 port is available, use HRN-CS14S21 Otherwise, N/A |
Universal 16-pin harness HRN-CG13S1-A + HRN-GS16K22-A OR Adapter harness HRN-CM24Y1-A + HRN-CE10K2 OR RP1226 harness HRN-CS14T2 |
If you are in California participating in the Clean Truck Check (CTC) Program, and there is a 16-pin diagnostic port, use the Universal Harness option. If you are not participating in the CTC, use the Adapter Harness. For more information, refer to the Installation Instructions |
| Mack |
MD Series |
2022+ |
N/A |
HRN-GS09K2-A |
|
Mercedes-Benz (Heavy-Duty and Medium-Duty) Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-Harness |
Notes |
| Mercedes |
Trucks and buses (Euro 3 / Euro 4) |
1995-2008 |
HRN-CW03K3 |
|
3-wire harness only, some models support engine data using IOX-UREADER |
| Mercedes |
Trucks and Buses (Euro 5 and Euro 6) |
2008+ |
HRN-BS16S4 |
HRN-GS16K22-A |
Dashboard message may appear when any device is connected to the OBD port of these vehicles. For more information, refer to https://myadmin.geotab.com/alerts |
| Mercedes |
Trucks and Buses (Euro 5 and Euro 6) |
2008+ |
HRN-CW03K3 + IOX-UREADER |
|
(Optional) For vehicles displaying dashboard message |
| Mercedes |
Trucks and Buses |
All |
HRN-ES12S1 |
|
For vehicles equipped with an FMS module |
Peterbilt Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Peterbilt |
All |
2000–2007 |
HRN-DS09S4 |
HRN-GS09K2-A |
Please confirm the diagnostic port, as in some cases the vehicle may have a 6-pin port and will require the HRN-DS06T2. |
| Peterbilt |
All |
2008-2018 |
N/A |
HRN-GS09K2-A |
To guarantee proper operation of the GO device, it is recommended that a GO9 is used exclusively for 2017+ Peterbilt. GO7 and GO8 devices may not work correctly with some motors (MX13 and MX15). |
| Peterbilt |
All models |
2019+ |
HRN-DS09S4 |
HRN-GS09K2-A |
|
| Peterbilt |
All models |
2021+ |
HRN-CS14S21 |
HRN-CS14T2 |
Alternative if the vehicle is equipped with a 14-pin (RP1226) port. If the RP1226 port is not available, or if the vehicle is operating in California and part of the Clean Truck Check (CTC) program, then use HRN-GS09K2-A with the diagnostic port. |
Sterling Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Sterling |
All (except Bullet) |
1997–1999 |
HRN-DS06S4 |
HRN-DS06T2-A |
|
| Sterling |
All (except Bullet) |
2000+ |
HRN-DS09S4 |
HRN-GS09K2-A |
|
| Sterling |
Bullet |
2008-2009 |
HRN-BS16S4 or HRN-BS16S4F |
HRN-GS16K22-A |
|
Volkswagen Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Volkswagen |
All heavy duty trucks |
|
|
HRN-CG04T3 |
It is a proprietary FMS connection for VW heavy Duty trucks |
Volvo North America Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Volvo |
All Heavy Duty (ie. VNM, VNL, VNX, VHD, VAH, VNR) |
2000–2003 |
HRN-DS09S4 or HRN-DS06S4 |
HRN-GS09K2-A or HRN-DS06T2-A |
Please confirm if there is a 6-pin or 9-pin diagnostics port on the truck. |
| Volvo |
All Heavy Duty |
2004-2012 |
N/A |
HRN-GS09K2-A |
Models from 2004 to 2012 can use either HRN-GS09K2-A or HRN-CM24Y1 & HRN-CE10K2. |
| Volvo |
All Heavy Duty (ie. VNM, VNL, VNX, VHD, VAH, VNR) |
2013-2018 |
N/A |
Universal harness HRN-CG13S1-A + HRN-GS16K22-A OR Adapter harness HRN-CM24Y1-A + HRN-CE10K2 |
If you are in California, participating in the Clean Truck Check (CTC) Program, and there is a 16-pin diagnostic port, use the universal harness option. If you are not participating in the CTC, use the adapter harness. For more information, refer to the Installation Instructions |
| Volvo |
All heavy duty models |
2019+ |
If RP1226 port available, use HRN-CS14S21 Otherwise, N/A |
Universal harness HRN-CG13S1-A + HRN-GS16K22-A OR Adapter harness HRN-CM24Y1-A + HRN-CE10K2 OR RP1226 harness HRN-CS14T2 |
If you are in California, participating in the Clean Truck Check (CTC) Program, and there is a 16-pin diagnostic port, use the universal harness option. If you are not participating in the CTC, use either the Adapter Harness or RP1226 Harness option. For more information, refer to the Installation Instructions |
| Volvo |
All Models with Cummins Engine |
TBD |
|
HRN-GS09K2-A |
For Volvo vehicles equipped with a Cummins engine, use HRN-GS09K2-A. |
Volvo Europe / Asia / Australasia / Latin America Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Volvo |
All models (FL / FE / FH / FM / FMX |
Euro 3/4 (2000 – 2008) |
HRN-CW03K3 |
N/A |
3-wire harness only, some models support engine data using IOX-UREADER |
| Volvo |
All Models (FL / FE / FH / FM / FMX |
Euro 5 (2008-2012) |
HRN-BS16S4 |
HRN-CG13S1-A + HRN-GS16K22-A |
Fuel data requires use of IOX-UREADER |
| Volvo |
All models (FL / FE / FH / FM / FMX) |
Euro 6 (2013-2025) |
HRN-BS16S4 |
HRN-CG13S1-A + HRN-GS16K22-A |
Fuel data requires use of IOX-UREADER |
| Volvo |
All models (FL / FE / FH / FM / FMX) |
All |
HRN-ES12S1 |
N/A |
For vehicles equipped with an FMS module |
| Volvo |
Electric FHE / FME |
2023+ |
HRN-BS16S4 |
HRN-CG13S1-A + HRN-GS16K22-A |
Must unclip the pin 3 and 11 shunt on the T-harness |
Western Star Vehicle Harnesses
| Make |
Model |
Year |
Straight Harness |
T-harness |
Notes |
| Western Star |
All |
2006+ |
HRN-DS09S4 |
HRN-GS09K2-A |
If the vehicle is equipped with a 14-pin (RP1226) port, you can order HRN-CS14S21 or HRN-CS14T2 instead. If the RP1226 port is not available, or if the vehicle is operating in California and part of the Clean Truck Check (CTC) program, then use HRN-GS09K2-A with the diagnostic port. |
Fire Truck Harnesses: Including E-ONE Considerations
Fire trucks, such as those from E-ONE, Oshkosh, Spartan, and Pierce, often utilize specific diagnostic port configurations. For many fire trucks manufactured from 2008 onwards, the HRN-GS09K2-A T-harness is commonly used. However, always verify the diagnostic port type on the specific fire truck model, including E-ONE engines, before selecting a harness. Due to the critical nature of fire truck operations, ensuring correct harness and telematics device installation is paramount for reliable vehicle monitoring and performance data.
| Make |
Model |
Year |
Straight harness |
T-harness |
Notes |
| Oshkosh |
All |
2008+ |
N/A |
HRN-GS09K2-A |
|
| Spartan |
All |
2008+ |
N/A |
HRN-GS09K2-A |
|
| E-ONE |
All |
2008+ |
N/A |
HRN-GS09K2-A |
|
| Pierce |
All |
2008+ |
N/A |
HRN-GS09K2-A |
|
Equipment & Off-Road Asset Harnesses
Note: GO RUGGED devices are mandatory for equipment and off-road assets due to their robust design and environmental resilience.
Harness selection for equipment and off-road assets requires careful consideration due to the diverse nature of these vehicles. Generally, these assets fall into categories:
- Equipment with engines under 25 hp or without diagnostic ports: These often require non-ECM harnesses like HRN-RW03K4, HRN-RW04K4, or HRN-RW03K5.
- Assets NOT considered on-highway vehicles: This broad category includes agricultural, construction, oil & gas, and recreational equipment. To verify on-highway status, use the NHTSA VIN decoder: https://vpic.nhtsa.dot.gov/decoder/. If a valid 17-character VIN is absent, the asset is likely off-road, and the table below applies.
| Make |
Model |
Year |
Straight harness |
T-harness |
Notes |
| All |
All |
HRN-RW03K4 |
|
Any vehicle without a diagnostic port. |
| All Equipment |
All |
2000+ |
See Notes |
HRN-GR09K1-A |
General guideline for all yellow iron equipment. Please check the table for specific manufacturers. Check for a diagnostic port. If no port exists, then only the HRN-RW03K4-A is required. See exceptions below. |
| Caterpillar |
All equipment with 9-pin Deutsch diagnostic port |
2000+ |
|
HRN-GR09K1-A + HRN-RMRCA1 |
Please confirm if the vehicle has a 9-pin diagnostic port. If not, refer to HRN-DC14T1 |
| Caterpillar |
All equipment with 14-pin Deutsch diagnostic port |
2016+ |
HRN-DC14S2 |
HRN-DC14T1 |
Note: Some models have a 9-pin Deutsch port instead of a 14-pin Deutsch port. Refer to 9-pin row for recommendation |
| John Deere |
All |
2000+ |
|
HRN-GR09K1-A |
Please confirm there is a diagnostic port prior to purchasing the harness. If no port exists, HRN-RW03K4-A is required. |
| Komatsu |
All |
2000-2009 |
|
HRN-GR09K1-A |
Please confirm there is a diagnostic port prior to purchasing the harness. If no port exists, HRN-RW03K4-A is required. |
| Komatsu |
All |
2010+ |
|
HRN-RC12T2 |
This harness is only compatible with Komatsu Tier 4 engines, and is not compatible with Tier 3 engines. In addition, please confirm there is a 12-pin diagnostic port prior to purchasing the harness. If no port exists, HRN-RW03K4-A is required. |
| Polaris |
All equipment with a diagnostic port. In particular, this includes smaller off-road vehicles such as snowmobiles and ATVs. |
2000+ |
HRN-RD04S1 |
N/A |
|
ECM and NON-ECM Harnesses for Specialized Applications
Note: GO RUGGED devices are mandatory for both ECM and NON-ECM applications.
Intelligent ECM (Engine Control Module) Harnesses
For vehicles with intelligent Engine Control Modules, specific harnesses ensure proper data integration.
| Harness |
Description |
| HRN-RZ04T41 |
Ford Model type Engine MSG-425. 2.5 liter (Ground Service Equipment). |
| HRN-RZ04T4 |
Kubota gasoline and diesel engines interface harness for the GO RUGGED device. |
NON-ECM Harnesses
For equipment without an Engine Control Module or without true ignition systems, specialized NON-ECM harnesses are required.
| Harness |
Description |
| HRN-RW04K4 |
All Equipment with Ground Disconnect on Asset and/or NON-ECM with no true ignition. |
| HRN-RW03K5 |
NON-ECM with no true ignition using Low Voltage/Primary side of ignition coil. |
Conclusion: Ensuring Correct OBD2 Port and Harness Utilization
Selecting the correct harness for your telematics device installation is vital for vehicle compatibility, data accuracy, and safety. By thoroughly assessing the vehicle, understanding OBD2 port standards and variations, and consulting compatibility resources like the tables provided, you can ensure a successful and reliable telematics deployment. Remember to always prioritize safety by using Geotab-approved harnesses and seeking professional installation when needed. For specific questions regarding E-ONE engine OBD2 port configurations or any other harness compatibility inquiries, contact Geotab Support or your Authorized Installer for expert assistance.
