Mastering Zonar
★ Zonar Products · Telematics Control Unit
The V4 is Zonar's main hardwired telematics unit for light, medium and heavy-duty vehicles and off-road equipment. Here is what it does, which version you have, what it needs at install time and where it fits in a fleet.
The Zonar V4 is a telematics control unit, the box that sits in the cab, talks to the engine computer and sends location and vehicle data to Zonar's platform over 4G LTE. Zonar introduced it in 2018 as the 4G successor to the 3G V3.
Unlike a plug-in tracker, the V4 is hardwired. It takes constant power, switched power and ground through a 4-pin power lead, and reads engine data through a separate cable that matches the vehicle: OBD-II on light-duty, a 9-pin Deutsch port on heavy trucks, or the J1708 and J1939 backbone. That is why the same V4 can go in a pickup, a school bus or a loader.
Zonar has sold five versions in the same housing, and they install the same way. The fastest way to tell them apart is the GPS ID on the back label: the first two digits name the model.
| Model | GPS ID starts with | Accelerometer | Bluetooth | Wi-Fi |
|---|---|---|---|---|
| V4 (part 10096) | 18 | Yes | Very limited | Yes, 2.4 GHz |
| V4 Base, V4B (part 10106) | 27 | Yes | BLE, limited | No |
| V4 Essential, V4E (part 10113) | 30 | No | BLE, limited | No |
| V4E-NBT (part 10129) | 34 | No | No | No |
| V4B2 (part 10134) | 38 | Yes | Yes | Yes, limited, 2.4 GHz |
For equipment that lives outside or gets pressure washed, Zonar also makes the V4R, a V4 in a rugged housing rated IP67 and IP69K.
School bus fleets. The V4 is the hub of Zonar's bus system. It logs door open and close events through the discrete inputs, docks the driver tablet and runs the Z Pass reader that records which students board and exit. Zonar states that many Thomas Built Saf-T-Liner, Minotour and C2 Jouley buses come with a V4 factory installed, and IC Bus offers factory fit or a Zonar pre-wire kit.
Municipal and public works trucks. Snowplow and spreader engagement, PTO hours on a bucket truck and idle time on a garbage truck all come from the same unit, which makes billing hours and maintenance intervals easier to prove.
Over-the-road and vocational trucks. Fault codes, ELD hours and inspection records from the 2010 reader all report through one box. Zonar lists integrations with Daimler Truck North America and International.
Construction and off-road equipment. A dedicated 4-wire power cable adds a chassis ground for machines with a battery disconnect on the negative side, and the V4R handles mud, dust and wash-downs.
| Spec | Detail |
|---|---|
| Dimensions | 6.0 x 3.85 x 1.25 in (153 x 98 x 32 mm); 6.31 x 4.03 x 1.65 in with the mounting bracket |
| Supply voltage | 8 to 32 VDC, 12 V and 24 V systems, reverse voltage protected |
| Operating current | 100 mA typical at 12 V, 500 mA maximum, without accessories |
| Key-off current | Under 1 mA |
| Operating temperature | -40 to +85 °C (-40 to 185 °F) |
| Humidity | 95% RH, non-condensing |
| Shock and vibration | SAE J1455, MIL-STD-202G |
| GNSS | GPS and GLONASS with QZSS, WAAS, EGNOS, MSAS and GAGAN augmentation, up to 2 Hz; Zonar's 2026 cutsheet also lists Galileo and BeiDou |
| GPS antenna | Internal patch antenna plus an SMA port for an external antenna; the unit switches between them automatically |
| Cellular | 4G LTE with an embedded industrial SIM; the current cutsheet lists LTE Category 1 on bands 1, 2, 4, 5, 8 and 12 (early V4 units were LTE Cat 4) |
| Storage | 4 GB eMMC flash |
| Vehicle data | Two CAN interfaces (250k or 500k baud) and one J1708/J1587 interface; OBD-II through the Light Duty cable |
| Other interfaces | Two RS-232 ports; two switched outputs (one 5 V, one vehicle voltage, each limited to 1 A) |
| Ports | External GPS antenna, 4-pin power, 6-pin Z Pass and operator ID, 8-pin 2010 and Connect dock, 12-pin discrete inputs, 10-pin ECM data |
| Inputs | Six general-purpose inputs (input 0 is a multi-use sense, inputs 1 to 5 take ground or battery-side signals); the optional discrete I/O cable brings five out as 20 AWG leads |
| Power loss | Attempts to send a final data packet when external power is cut |
| Warranty | 3 years |
| Sound | None. The V4 has no buzzer; it reports through five LEDs |
Most V4 problems trace back to the white wire. It is the switched power lead, and it must be live only when the engine is running. Zonar is specific that it should read 0 volts with the key in accessory, so a plain ignition circuit that stays hot in accessory gives wrong idle times, cold-start flags and straight-line gaps in the trail. Fuse both the red constant and the white switched leads at 3 to 5 amps as close to the source as possible, keep the black ground under 1 ohm to the chassis, and stay off the noise-kill circuit on late-model school buses. Zonar approves only Littelfuse and Bussmann add-a-circuit fuse taps, never in a fuse slot above 10 amps. Pick the data cable by vehicle: the 9-pin cable for heavy-duty J1939 ports, the 6-pin adapter for older J1708 trucks, the backbone cable with an engine-specific adapter where needed, and the Light Duty kit for OBD-II. Plug the 4-pin power in last, start the engine, then connect OBD-II. Mount the unit flat, logo up, with a clear view of the sky through glass or fiberglass, and add the external antenna anywhere metal blocks it. Finally, drive the vehicle at least 100 feet at 5 mph or more, or the account will not show GPS or input data yet.
The V4 fits any fleet that needs more than location: engine faults, ELD hours, equipment inputs, inspections or rider tracking. It is the standard choice for buses, medium and heavy trucks and mixed fleets that want one unit type across every class of vehicle.
A fleet of only cars, pickups and vans that just needs tracking and diagnostics should ask Zonar about the LD TCU first, which plugs into the OBD-II port with no wiring. Equipment parked outside or washed often belongs on a V4R, and trailers or unpowered assets belong on a battery-powered ZTrak. We can supply and install whichever one matches the vehicle.
Read the GPS ID on the back label. Zonar uses the first two digits to identify the model: 18 is the original V4, 27 is the V4 Base, 30 is the V4 Essential, 34 is the V4E-NBT and 38 is the V4B2.
Yes, with Zonar's Light Duty cable kit, as long as the vehicle is labeled OBD-II compliant, is not a hybrid, and has no other aftermarket device on the OBD-II network. For a light-duty-only fleet, Zonar also makes the LD TCU, which plugs straight into the port.
Zonar requires a new install on the 3-wire, 4-wire or Light Duty cable to drive at least 100 feet at 5 mph or more. Until that happens, GPS and discrete input data will not appear in Ground Traffic Control.
No. The V4 has no buzzer or tone. Everything it tells the installer comes through its five LEDs: Cellular, GPS, Status, DataLink 1 and DataLink 2. The V4 Technical Information page shows what every light pattern means.
When you are ready to put V4 units in your vehicles, API Signal supplies the unit with the right power and data cables, and our technicians install it on site at your yard so the trucks never leave your lot. Call 803-513-1009 or use Get a Quote to set a date.
Sources: Zonar V4 cutsheet and specifications (2026), Zonar V4 User Manual and Installation Guide, Zonar GPS LED States, Zonar Glossary, Zonar fleet telematics devices page, Zonar V4 product page. ZONAR is a trademark of Zonar Systems, Inc. API Signal is an independent installer and is not Zonar.
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