> ## Documentation Index
> Fetch the complete documentation index at: https://helpdocs.servinix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Install DataLogger on a medium-duty vehicle

> Install the DataLogger on a Class 4–6 medium-duty vehicle in Servinix GPS Tracking using an OBDII, 6-pin, or 9-pin port and the matching cable.

# Install DataLogger on a medium-duty vehicle

**Step 4 of 6 — Install on a medium-duty vehicle (Class 4–6)**

Install the DataLogger on a Class 4–6 vehicle by identifying the available diagnostic port and connecting the device directly or with the correct cable. Medium-duty vehicles can have an OBDII port, a 6-pin port, a 9-pin port, or multiple port types.

## Before you start

* Confirm your vehicle is a **Class 4–6 medium-duty vehicle**.
* Inspect the vehicle to identify which diagnostic port(s) are present before you begin (see Step 2 below).
* Have the DataLogger device and any cables from your shipment ready.
* The vehicle must be turned off before you begin.
* If you have not yet received and inspected your shipment, complete [Receive and inspect your device shipment](/gps-tracking/device-setup/receive-and-inspect-your-device-shipment) first.

## Steps

1. **Turn the vehicle off.**
2. **Locate and identify the diagnostic port(s).** Medium-duty vehicles can have an OBDII port, a 6-pin port, a 9-pin port, or a combination. It is common to find multiple port types, especially on vehicles from manufacturers who also produce light-duty vehicles.
3. **Determine which port to use:**
   * If only one port is present, use that port.
   * If the vehicle has an OBDII port and comes from a manufacturer who also builds light-duty vehicles, the OBDII port is the preferred choice for installation.
   * If no OBDII port is present, or if the vehicle is from a manufacturer that does not build light-duty vehicles, use the 6-pin or 9-pin port.
4. **Install the device based on port type:**
   * **OBDII port:** Firmly install the device directly into the OBDII port. No cable required.
   * **6-pin or 9-pin port:** Use the supplied cable.
     1. Firmly connect the device to the 16-pin end of the cable.
     2. Connect the 6-pin or 9-pin end of the cable to the vehicle diagnostic port.
5. **Check the LED indicators.** The LEDs should illuminate, confirming the device is receiving power. LEDs may extinguish after a period of time — this is normal.
6. **Secure the device and cable.** Tuck the assembly behind vehicle paneling. Use zip ties, double-sided tape, or Velcro to secure it in place. The device must remain stationary and must not be able to move freely — movement can cause rattling, rubbing, or connector wear.

## Extension and Y-cable situations

Extension cables and Y-cables are available for OBDII, 6-pin, and 9-pin ports:

* **Extension cable:** Use when the diagnostic port is in an inconvenient location and the device or cable assembly would interfere with the driver or safe vehicle operation.
* **Y-cable:** Use when the diagnostic port must remain accessible for other tools while the device is installed.

Contact Servinix support to request extension or Y-cables.

## Result / verify

The device LEDs illuminate (or illuminate briefly) after connecting, confirming it has power. Proceed to [Verify device connection](/gps-tracking/device-setup/verify-device-connection) to confirm data is flowing to Servinix.

## Troubleshooting

* **Unsure whether to use the OBDII or 6/9-pin port when both are present:** Default to OBDII if the vehicle manufacturer also builds light-duty vehicles. Otherwise, use the 6-pin or 9-pin port.
* **Cable connector does not fit the vehicle port:** Do not force the connection. Contact Servinix support — you may have received the wrong cable type. See [Device install cable mismatch](/gps-tracking/gps-troubleshooting/device-install-cable-mismatch).
* **LEDs do not illuminate:** Confirm the cable is firmly connected at both ends. Try re-seating. If LEDs still do not light, see [Device LEDs off after install](/gps-tracking/gps-troubleshooting/device-leds-off-after-install).

## Related

* [Install DataLogger on a light-duty vehicle](/gps-tracking/device-setup/install-datalogger-light-duty-vehicle) — Step 3 of 6
* [Install DataLogger on a heavy-duty vehicle](/gps-tracking/device-setup/install-datalogger-heavy-duty-vehicle) — Step 5 of 6
* [Verify device connection](/gps-tracking/device-setup/verify-device-connection) — Step 6 of 6
* [Device install cable mismatch](/gps-tracking/gps-troubleshooting/device-install-cable-mismatch)