1
Test at the OBD port
This is where the taximeters connect. We sent the same standard odometer request (PID A6) the meters use, plus other read-only requests a normal scan tool sends.
Case Study·Passenger Transport·October 2026
Recovering Odometer Data from CAN Bus for Kabi Taxi
For months, Kabi Taxi's setup could not read the odometer on its Camry Hybrid taxis. In 2 hours, Truckoom found which module answers the request and proved the readings accurate to the kilometre.
Kabi TaxiDubai taxi operator whose Toyota Camry Hybrid taxis carry speed limiters and smart taximeters.
- to decode the odometer, after months with no data
- wheel run matched to the dashboard, to the kilometre
- independent data routes confirmed
- wires cut, moved or disconnected
to decode the odometer, after months with no data
wheel run matched to the dashboard, to the kilometre
independent data routes confirmed
wires cut, moved or disconnected
The Challenge
Kabi Taxi operates taxis in Dubai. Each taxi already carries a speed limiter and a smart taximeter connected through the vehicle's OBD port. For a taxi operator, the odometer is a core business number. It drives maintenance schedules, tyre and service intervals, vehicle utilisation reports, fuel and cost-per-km analysis, and audit trails for regulators.
Kabi Taxi's connected setup could not read the odometer from its Toyota Camry 2023 Hybrid taxis. The equipment was installed and connected, but no odometer value ever came through, and the existing solution had been unable to fix it for months.
The constraints made the problem harder.
No interference allowed. The speed limiter and taximeter are regulated equipment. Their wiring could not be cut, moved or disturbed.
No published data. Manufacturers do not publish where the odometer sits on the vehicle's CAN bus, or how it is encoded.
A modern, gated vehicle. Newer vehicles place a security gateway between the OBD port and the car's internal networks, hiding most of the data a device would normally see.
The Solution
Truckoom Telematics ran a structured, read-only diagnosis on a live Kabi Taxi vehicle in four stages. Nothing was sent to the vehicle behind the cluster, and the speed limiter and taximeter connections were never touched.
2
Map which modules answer
Controlled tests sent requests to all modules and to individual modules, in ignition-only and hybrid READY mode.
3
Check behind the instrument cluster
A contactless clip in listen-only mode showed whether the odometer is also broadcast on the vehicle side of the gateway. Over 115 data channels were visible there, against 1 to 2 at the OBD port.
4
Prove it on the lift
With the front wheels turning on a lift, we compared both readings with the dashboard before, during and after an 8 km wheel run. Both routes matched exactly, and the broadcast value climbed one kilometre at a time without ever jumping or decreasing.
Validation: proven on the lift
Readings taken before and after an 8 km wheel run, with the front wheels turning on a lift.
| Stage | Dashboard | Broadcast odometer (behind cluster) | Diagnostic request (OBD port) |
|---|---|---|---|
| Before | 686,842 km | 686,842 km | 686,842.3 km |
| After | 686,850 km | 686,850 km | 686,850.6 km |
The diagnostic route even reports to a tenth of a kilometre.
Conclusion
The car does report its odometer through the standard OBD request. The answer simply came from a module the taximeters were not listening to. The meters send the A6 request and wait for a reply from the engine unit (7E8), which never answers it. On this hybrid, only the hybrid control unit replies (reply ID 7EA), so the meters received nothing.
Listening at the port was not an option either, because a security gateway behind the OBD port blocks the vehicle's broadcast traffic. Behind the cluster, on the vehicle side of the gateway, we confirmed the odometer is broadcast on Toyota's own CAN message about once per second. That gave a second, independent reference.
The fix needs no vehicle changes: a meter firmware update so the meter accepts the odometer reply from the hybrid control unit, ideally from any engine or hybrid module.
After months without odometer data, and about 2 hours of decoding, Kabi Taxi now has a confirmed, accurate odometer source for its Camry Hybrid fleet, with two independent ways to read it. Existing equipment stayed exactly as installed, every test was read-only, and the same method can be applied model by model across the rest of the fleet.
Hybrids are now standard in taxi fleets, but much in-vehicle equipment was designed around conventional engines and older vehicle networks. When such a device reports "no data", the data is often still there, coming from a different module or sitting behind a gateway. Truckoom combines CAN bus expertise with practical, non-invasive installation, so fleets get the data they need without risking regulated equipment or vehicle warranties.
About the solution